/***************************************************************************
  Yvan Petillot
  Heriot Watt University

  Version 1.0   October, 2002 Yvan Petillot Initial Coding
****************************************************************************/
#include       <sys/types.h>
#include       <fcntl.h>
#include       <netdb.h>
#include       <sys/socket.h>
#include       <netinet/in.h>
#include       <unistd.h>
#include       <string.h>
#include       <errno.h>
#include       <stdio.h>
#include       <stdlib.h>

#define         TRUE            1
#define         FALSE           0
#define         BUFFER_SIZE     1000
#define         PORT            10000

void    SysError( char * );

 /* Thread used to handle send and receive */
pthread_t          chat_send;
pthread_t          chat_receive;

/* Socket use by main and threads */
struct sockaddr_in my_addr;                /* Structure storing socket info */
struct sockaddr_in their_addr;           /* Structure storing socket info */
int fd;   /* Socket id. On Unix a socket is a file descriptor */


/* function prototypes */
void thread_chat_send(void);
void thread_chat_receive(void);

char name[80];

/* Main Program */
main ( int argc, char *argv[] )
{
  int                family = AF_INET;       /* The default for most cases */
  int                type   = SOCK_STREAM;    /* Says it's a UDP connection */
  int                lsa = sizeof(my_addr);
  int                on;
  void *status;
  
  /* Checks first we have the correct number of arguments */
  if ( argc < 2 ) {
    printf( "The program expects arguments\n" );
    printf( "udp Name\n" );
    exit(0);
  }
  strcpy(name,argv[1]);
  /* Create socket*/
  if ((fd = socket (family, type, 0)) < 0)
    {
      SysError ("Error on socket");
    }
  /* Fills my_addr socket structure with correct fields */
  my_addr.sin_family       = family;
  my_addr.sin_port         = (PORT);              
  my_addr.sin_addr.s_addr  = htonl(0xFFFFFFFF); //Any addr
  
   /* Fills their socket structure with correct fields */
  their_addr.sin_family       = family;
  their_addr.sin_port         = (PORT);
  their_addr.sin_addr.s_addr  = htonl(0xFFFFFFFF); // Any addr

  /*memcpy((char *)&their_addr.sin_addr, (char *)host->h_addr, host->h_length);
    printf("%x\n",host->h_addr);*/
  on = 1;
  setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on));
  setsockopt(fd,SOL_SOCKET,SO_BROADCAST,&on,sizeof(on));

  /* First bind fd and sa structure*/ 
  if (bind (fd, (struct sockaddr *)&my_addr, sizeof(my_addr) ) == -1)
    SysError ("Error on bind");
  
  if(pthread_create(&chat_send,NULL, (void*) thread_chat_send,NULL)!=0)
    {
      SysError("Cannot create send thread");
    }
  if(pthread_create(&chat_receive,NULL, (void*) thread_chat_receive,NULL)!=0)
    {
      SysError("Cannot create send thread");
    }
  pthread_join(chat_send,&status);
  pthread_join(chat_receive,&status);
}                                 
/* End of main          */


void thread_chat_send()
{
  int                count;
  char               console_buffer[BUFFER_SIZE];
  char               ip_input_buffer[BUFFER_SIZE];
  char               ip_output_buffer[BUFFER_SIZE];

  /* First Say you are online! */

  /* Make sure output buffer is empty */
  bzero( ip_output_buffer, sizeof( ip_output_buffer ));
  /* Copy value to output buffer */
  strcpy( ip_output_buffer, name);
  strcat( ip_output_buffer," is on line ");
  count = sendto(fd, ip_output_buffer, strlen(ip_output_buffer), 0,&their_addr,sizeof(their_addr) );
  if (count == 0)
    SysError( "Error on send" );
  /* Infinite loop until fault */
  
  while( TRUE )
    {
      /* Get a number from console */
      printf( "%s> ",name);
      gets(&console_buffer );
      /* Convert it to integer (-1 to exit)*/
      if ( atoi( console_buffer ) == -1 )
	{
	  printf( "We Have Successfully Finished.\n" );
	  exit(0);
	}
      /* Make sure output buffer is empty */
      bzero( ip_output_buffer, sizeof( ip_output_buffer ));
      /* Copy value to output buffer */
      strcpy( ip_output_buffer, name);
      strcat( ip_output_buffer," says ");
      strcat( ip_output_buffer, console_buffer);
      //strcpy( ip_output_buffer, console_buffer );
	  /* Send value to other machine */
      count = sendto(fd, ip_output_buffer, strlen(ip_output_buffer), 0,&their_addr,sizeof(their_addr) );
      if (count == 0)
	SysError( "Error on send" );
    }  
  close(fd);
}

void thread_chat_receive()
{
  int                count;
  char               console_buffer[BUFFER_SIZE];
  char               ip_input_buffer[BUFFER_SIZE];
  char               ip_output_buffer[BUFFER_SIZE];
  /* Infinite loop until fault */
  while( TRUE )
    {
      bzero( ip_input_buffer, sizeof(ip_input_buffer) );
      /* receive data back from machine */
      count = recvfrom( fd, ip_input_buffer,sizeof(ip_input_buffer),0,&their_addr,sizeof(their_addr));
      if (count == 0)
	SysError( "Error on recv" );
      /*Print reception */
      printf( "%s\n", ip_input_buffer );
    }  
  close(fd);
}

void    SysError( char *string )
{
  printf( "Error found:  String given is --> %s\n", string );
  exit(0);
}