#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>

#include "readLine.h"

#ifndef BOOL
#define BOOL int
#define TRUE 0
#define FALSE 1
#endif

#define PORT 7777
#define BACKLOG 10

int done[2];

int comunicacao(int socket){
  char tmp[1];
  char *buff = NULL;
  unsigned int size = 0;
  unsigned int i = 0;

  while(recv(socket,&tmp,1,(int)NULL) != 0){
    size++;
    if((buff=(char*)realloc(buff,sizeof(char)*size))==NULL){
      perror("realloc");
      close(socket);
      write(done[1],"0",1); /* Major failure, stop the server */
      exit(EXIT_FAILURE);
    }
    buff[size]='\0';
    buff[i++]=tmp[0];
    if(tmp[0]=='\n') break;
  }
  if(send(socket,buff,size,(int)NULL) < 0){
    perror("send");
    close(socket);
    free(buff);
    exit(EXIT_FAILURE); /* Apesar de ser um erro e inutilizar o servidor na maioria das vezes...eh apenas na maioria das vezes */
  }
  if(strncmp(buff,"STOP SERVER\n",strlen("STOP SERVER\n"))==0){
    if(send(socket,"STOPING\n",strlen("STOPING\n"),MSG_DONTWAIT) < 0){
      perror("send");
    }
    write(done[1],"0",1);
  }
  free(buff);

  close(socket);
  return 0;
}

void sigchld_handler(int s){
  int childStatus;
  while(waitpid(-1,&childStatus,WNOHANG) > 0);
  if(WIFEXITED(childStatus)){
    if(WEXITSTATUS(childStatus)!=0)
      perror("child");
  }
}

int main(int argc, char *argv[]){
  struct sockaddr_in server, client;
  int serverSock, clientSock;
  socklen_t clientSize = 0;
  pid_t clientPid;
  struct sigaction sa;
  BOOL stop = FALSE;
  char tmp;
  tmp='1';

  memset(&server,'\0',sizeof(struct sockaddr_in));
  memset(&client,'\0',sizeof(struct sockaddr_in));

  if(pipe(done) < 0){
    perror("pipe");
    exit(EXIT_FAILURE);
  }
  
  if(fcntl(done[0],F_SETFL,O_NONBLOCK) < 0)
    perror("fcntl");
  if(fcntl(done[1],F_SETFL,O_NONBLOCK) < 0)
    perror("fcntl");

  if((serverSock = socket(AF_INET,SOCK_STREAM,0))==0){
    perror("socket");
    exit(EXIT_FAILURE);
  }

  if(fcntl(serverSock,F_SETFL,O_NONBLOCK) < 0)
    perror("fcntl");

  server.sin_family = AF_INET;
  server.sin_port = htons(PORT);
  server.sin_addr.s_addr = INADDR_ANY;

  if(bind(serverSock,(struct sockaddr *)&server,sizeof(struct sockaddr)) < 0){
    perror("bind");
    exit(EXIT_FAILURE);
  }

  if(listen(serverSock,BACKLOG) < 0){
    perror("bind");
    exit(EXIT_FAILURE);
  }

  clientSize = sizeof(client);

  sa.sa_handler = sigchld_handler;
  sigemptyset(&sa.sa_mask);
  sa.sa_flags = SA_RESTART;
  if(sigaction(SIGCHLD,&sa,NULL) < 0){
    perror("sigaction");
    exit(EXIT_FAILURE);
  }

  while(stop==FALSE){
    read(done[0],&tmp,1);
    if(tmp=='0') stop=TRUE;
    tmp='1';

    if((clientSock = accept(serverSock,(struct sockaddr*)&client,&clientSize)) < 0){
      if(errno!=EAGAIN || errno!=EWOULDBLOCK)
	perror("accept");
    }
    if(clientSock > 0){
      clientPid = fork();
      if((int)clientPid < 0 ){
	perror("fork");
      }
      if((int)clientPid == 0){ /* Se este for o cliente */
	close(serverSock);
	comunicacao(clientSock);
	exit(0); /* Saimos do cliente */
      
      }else{      
	close(clientSock); /* O servidor nao precisa disso */
	read(done[0],&tmp,1);
	if(tmp=='0') stop=TRUE;
	tmp='1';
      }
    }
  }
  close(serverSock);
  exit(EXIT_SUCCESS);
}