/* chatserver.c - a simple chat demo
 * (based on echoserveri.c)
 */ 

#include "csapp.h"

void chat_receive(int connfd);
void chat_send(int connfd);

int main(int argc, char **argv){
  int listenfd, connfd;
  pid_t pid;    
  socklen_t clientlen;
  struct sockaddr_storage clientaddr;  /* Enough space for any address */
  char client_hostname[MAXLINE], client_port[MAXLINE];

  if (argc != 2) {
    fprintf(stderr, "usage: %s <port>\n", argv[0]);
    exit(0);
  }

  listenfd = Open_listenfd(argv[1]);
  while (1){
    printf("Waiting for client connection ... \n");
    
    clientlen = sizeof(struct sockaddr_storage); 
    connfd = Accept(listenfd, (SA *)&clientaddr, &clientlen);
    Getnameinfo((SA *) &clientaddr, clientlen, client_hostname, MAXLINE, 
		client_port, MAXLINE, 0);
    printf("Connected to (%s, %s)\n", client_hostname, client_port);

    if (pid = Fork()){
      // -- parent -- 
      chat_receive(connfd); // loop: receive lines, write to terminal
      // done when other end closes connection
      kill(pid, SIGINT);    // get rid of child (which is reading user input)
      // TODO: reap children with waitpid ?
      Close(connfd);
      // ... and continue, waiting for the next connection.
    }
    else {
      // -- child -- 
      chat_send(connfd);   // loop: send user input to remote process
      // stopped by parent after other end stops sending
    }
    
  } // end while(1)

  // The while(1) is an infinite loop, so we never get here.
  // To quit the program, type control-C.
  exit(0);
}