#include "main.h"

//======================================================================

void * dialogThread(void *arg)
{
	char buffer[0x100];
	int ok;
	
	pthread_detach(pthread_self());
	//---- obtain dialog socket from arg ----
	int dialogSocket=*(int*)arg;
	free(arg);
	for(;;)
	  {
			  //---- receive and display message from client ----
			  int nb=recv(dialogSocket,buffer,0x100,0);
			  if(nb<=0) { break; }
			  buffer[nb]='\0';
			  printf("%s\n",buffer);

			  //---- send reply to client ----
			  nb=sprintf(buffer,"%d bytes received\n",nb);
			  ok = send(dialogSocket,buffer,nb,0);
									if( ok == -1 ){ perror("send"); exit(1); }
	  }

	//---- close dialog socket ----
	printf("client disconnected\n");
	close(dialogSocket);
	return (void *)0;
}

//======================================================================
//						MAIN
//======================================================================

int main(int argc,  char **argv)
{
	int ok;
	int portNumber;
	struct sockaddr_in myAddr;
	struct sockaddr_in fromAddr;
	
	//---- check command line arguments ----
	if(argc!=2)
				{ fprintf(stderr,"usage: %s port\n",argv[0]); exit(1); }

	//---- extract local port number ----
	ok = sscanf(argv[1],"%d",&portNumber);
				if( ok == -1 ){ fprintf(stderr,"invalid port %s\n",argv[1]); exit(1); }

	//---- create listen socket ----
	int listenSocket=socket(PF_INET,SOCK_STREAM,0);
	if(listenSocket==-1)
				{ perror("socket"); exit(1); }
	// ... avoiding timewait problems (optional)
	int on=1;
	ok = setsockopt(listenSocket,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(int));
				if( ok == -1 ){ perror("setsockopt"); exit(1); }
				
	// ... bound to any local address on the specified port
	myAddr.sin_family=AF_INET;
	myAddr.sin_port=htons(portNumber);
	myAddr.sin_addr.s_addr=htonl(INADDR_ANY);
	if(bind(listenSocket,(struct sockaddr *)&myAddr,sizeof(myAddr))==-1)
	  { perror("bind"); exit(1); }
	// ... listening connections
	if(listen(listenSocket,10)==-1)
							{ perror("listen"); exit(1); }

	for(;;)
	  {
		  //---- accept new connection ----
		  socklen_t len=sizeof(fromAddr);
		  int dialogSocket=accept(listenSocket,(struct sockaddr *)&fromAddr,&len);
		  if(dialogSocket==-1)
							{ perror("accept"); exit(1); }
		  printf("new connection from %s:%d\n",
				 inet_ntoa(fromAddr.sin_addr),ntohs(fromAddr.sin_port));

		  //---- start a new dialog thread ----
		  pthread_t th;
		  int *arg=(int *)malloc(sizeof(int));
		  *arg=dialogSocket;
		  if(pthread_create(&th,(pthread_attr_t *)0,dialogThread,arg))
							{ fprintf(stderr,"cannot create thread\n"); exit(1); }
	  }
	  
	close(listenSocket);
	return 0;
}

//----------------------------------------------------------------------------