#include "local.h"
#include "utils.h"

using namespace std;

// chat message buffer
char message[BUF_SIZE];

// for debug mode
int DEBUG_MODE = 0;

/*
  We use 'fork' to make two process.
      Child process:
          - waiting for user's input message;
              - and sending all users messages to parent process through pipe.
                  ('man pipe' has good example how to do it)
                  
                      Parent process:
                          - wating for incoming messages(EPOLLIN):
                              -- from server(socket) to display;
                                  -- from child process(pipe) to transmit to server(socket)
                                       
                                       */
                                       
                                       int main(int argc, char *argv[])
                                       {
                                               // *** Define debug mode
                                                       //     any additional parameres on startup
                                                               //     i.e. like './client f' or './client debug'
                                                                       //     we will switch to debug mode(very simple anmd useful)
                                                                               if(argc > 1) DEBUG_MODE = 1;
                                                                               
                                                                                       if(DEBUG_MODE){
                                                                                                       printf("Debug mode is ON!\n");
                                                                                                                       printf("MAIN: argc = %d\n", argc);
                                                                                                                                       for(int i=0; i<argc; i++)
                                                                                                                                                               printf(" argv[%d] = %s\n", i, argv[i]);
                                                                                                                                                                       }else printf("Debug mode is OFF!\n");
                                                                                                                                                                       
                                                                                                                                                                               // *** Define values
                                                                                                                                                                                       //     socket connection with server(sock)
                                                                                                                                                                                               //     process ID(pid)
                                                                                                                                                                                                       //     pipe between chils & parent processes(pipe_fd)
                                                                                                                                                                                                               //     epoll descriptor to watch events
                                                                                                                                                                                                                       int sock, pid, pipe_fd[2], epfd;
                                                                                                                                                                                                                       
                                                                                                                                                                                                                               //     define ip & ports for server(addr)
                                                                                                                                                                                                                                       struct sockaddr_in addr;
                                                                                                                                                                                                                                               addr.sin_family = PF_INET;
                                                                                                                                                                                                                                                       addr.sin_port = htons(SERVER_PORT);
                                                                                                                                                                                                                                                               addr.sin_addr.s_addr = inet_addr(SERVER_HOST);
                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                       //     event template for epoll_ctl(ev)
                                                                                                                                                                                                                                                                               //     storage array for incoming events from epoll_wait(events)
                                                                                                                                                                                                                                                                                       //     and maximum events count could be 2
                                                                                                                                                                                                                                                                                               //     'sock' from server and 'pipe' from parent process(user inputs)
                                                                                                                                                                                                                                                                                                       static struct epoll_event ev, events[2]; // Socket(in|out) & Pipe(in)
                                                                                                                                                                                                                                                                                                               ev.events = EPOLLIN | EPOLLET;
                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                       //     if it's zero, we should shoud down client
                                                                                                                                                                                                                                                                                                                               int continue_to_work = 1;
                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                       // *** Setup socket connection with server
                                                                                                                                                                                                                                                                                                                                               CHK2(sock,socket(PF_INET, SOCK_STREAM, 0));
                                                                                                                                                                                                                                                                                                                                                       CHK(connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0);
                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                               // *** Setup pipe to send messages from child process to parent
                                                                                                                                                                                                                                                                                                                                                                       CHK(pipe(pipe_fd));
                                                                                                                                                                                                                                                                                                                                                                               if(DEBUG_MODE) printf("Created pipe with pipe_fd[0](read part): %d and pipe_fd[1](write part): % d\n",
                                                                                                                                                                                                                                                                                                                                                                                                       pipe_fd[0],
                                                                                                                                                                                                                                                                                                                                                                                                                               pipe_fd[1]);
                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                       // *** Create & configure epoll
                                                                                                                                                                                                                                                                                                                                                                                                                                               CHK2(epfd,epoll_create(EPOLL_SIZE));
                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(DEBUG_MODE) printf("Created epoll with fd: %d\n", epfd);
                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                               //     add server connetion(sock) to epoll to listen incoming messages from server
                                                                                                                                                                                                                                                                                                                                                                                                                                                                       ev.data.fd = sock;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                               CHK(epoll_ctl(epfd, EPOLL_CTL_ADD, sock, &ev));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(DEBUG_MODE) printf("Socket connection (fd = %d) added to epoll\n", sock);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               //     add read part of pipe(pipe_fd[0]) to epoll
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       //     to listen incoming messages from child process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ev.data.fd = pipe_fd[0];
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CHK(epoll_ctl(epfd, EPOLL_CTL_ADD, pipe_fd[0], &ev));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(DEBUG_MODE) printf("Pipe[0] (read) with fd(%d) added to epoll\n", pipe_fd[0]);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // Fork
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               CHK2(pid,fork());
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       switch(pid){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       case 0: // child process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               close(pipe_fd[0]); // we dont need read pipe anymore
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       printf("Enter 'exit' to exit\n");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               while(continue_to_work){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               bzero(&message, BUF_SIZE);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               fgets(message, BUF_SIZE, stdin);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               // close while cycle for 'exit' command
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(strncasecmp(message, CMD_EXIT, strlen(CMD_EXIT)) == 0){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       continue_to_work = 0;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               // send user's message to parent process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               }else CHK(write(pipe_fd[1], message, strlen(message) - 1));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               break;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               default: //parent process
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       close(pipe_fd[1]); // we dont need write pipe anymore
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               // incoming epoll_wait's events count(epoll_events_count)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // results of different functions(res)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               int epoll_events_count, res;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // *** Main cycle(epoll_wait)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               while(continue_to_work) {
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               CHK2(epoll_events_count,epoll_wait(epfd, events, 2, EPOLL_RUN_TIMEOUT));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(DEBUG_MODE) printf("Epoll events count: %d\n", epoll_events_count);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               for(int i = 0; i < epoll_events_count ; i++){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       bzero(&message, BUF_SIZE);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               // EPOLLIN event from server( new message from server)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(events[i].data.fd == sock){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(DEBUG_MODE) printf("Server sends new message!\n");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CHK2(res,recv(sock, message, BUF_SIZE, 0));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // zero size of result means the server closed connection
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(res == 0){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(DEBUG_MODE) printf("Server closed connection: %d\n", sock);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CHK(close(sock));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               continue_to_work = 0;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               }else printf("%s\n", message);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               // EPOLLIN event from child process(user's input message)
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }else{
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(DEBUG_MODE) printf("New pipe event!\n");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       CHK2(res, read(events[i].data.fd, message, BUF_SIZE));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // zero size of result means the child process going to exit
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(res == 0) continue_to_work = 0; // exit parent to
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       // send message to server
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       else{
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               CHK(send(sock, message, BUF_SIZE, 0));
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(pid){
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               if(DEBUG_MODE) printf("Shutting down parent!\n");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               close(pipe_fd[0]);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               close(sock);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }else{
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       if(DEBUG_MODE) printf("Shutting down child!\n");
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       close(pipe_fd[1]);
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       return 0;
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       }