#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <inttypes.h>
#include <netdb.h>
#include <ctype.h>
#include <netinet/in.h>
#include <errno.h>
#include <netinet/tcp.h>
#define _GNU_SOURCE
#define BDP 625


static void error_report ( const char *on_what )
{
	perror ( on_what );
	exit ( EXIT_FAILURE );
}

int main ( int argc , char **argv )
{
	int32_t tcp_socket = 0;//this will store the return value from the socket()
	char *srvr_addr = "[i]A.B.C.D[/i]";//change it according to the server IP.
	char *srvr_port = "[i]ABCD[/i]";//as you wish....
	struct sockaddr_in adr_srvr;
	struct sockaddr_in adr_clnt;
	int32_t accept_return = 0;
	int32_t listen_return = 0;
	int32_t recv_return = 0;
	int32_t send_return = 0;
	char *mesg_recv = NULL;
	char *substring = NULL;
	int32_t len_clnt = 0;
	int32_t bind_return = 0;
	uint32_t size_recv = 0;
	int32_t i = 0;
	int32_t j = 0;
	uint32_t size_substring = 0;
	uint32_t size_file_name = 0;
	char *file_name = NULL;
	uint32_t flag = 0;
	FILE *output_file;
	int32_t return_setsockopt = 0;
	int32_t sock_buf_size = 0;
	char *mesg = "this is a test mesg from linux";

		
	if ( argc > 2 )
	{
		srvr_addr = argv[1];
	}
	else
	{
		srvr_addr = "144.0.6.96";
	}
	if ( argc >= 3 )
	{
		srvr_port = argv[2];
	}
	
	tcp_socket = socket ( AF_INET , SOCK_STREAM , IPPROTO_TCP);
	if ( tcp_socket == -1 )
	{
		error_report ( "socket() malfunction" );
	}
	flag = 1;
	return_setsockopt = setsockopt ( tcp_socket , IPPROTO_TCP , TCP_NODELAY , ( char * )&flag , sizeof ( flag ) );
	if ( return_setsockopt == -1 )
	{
		printf ( "Couldn't setsockopt(TCP_NODELAY)\n");
		exit(EXIT_FAILURE);
	}
	sock_buf_size = BDP;
	return_setsockopt = setsockopt ( tcp_socket , SOL_SOCKET , SO_SNDBUF , ( char * )&sock_buf_size , sizeof ( sock_buf_size ) );
	if ( return_setsockopt == -1 )
	{
		error_report ( "setsockopt() malfunction" );
	}
	return_setsockopt = setsockopt ( tcp_socket , SOL_SOCKET , SO_RCVBUF , ( char * ) &sock_buf_size , sizeof ( sock_buf_size ) );
	if ( return_setsockopt == -1 )
	{
		error_report ( "setsockopt() error" );
	}

	flag = 0;
	memset ( &adr_srvr , 0 , sizeof ( adr_srvr ) );
	adr_srvr.sin_family = AF_INET;
	adr_srvr.sin_port = htons ( atoi ( srvr_port ) );
	adr_srvr.sin_addr.s_addr = inet_addr ( srvr_addr );
	bind_return = bind ( tcp_socket , ( struct sockaddr * ) &adr_srvr , sizeof ( adr_srvr ) );
	if ( bind_return == -1 )
	{
		error_report ( "bind() malfunction" );
	}
	listen_return = listen ( tcp_socket , 254 );
	if ( listen_return == -1 )
	{
		error_report ( "listen() malfunction " );
	}
	
	for ( ; ; )
	{
		output_file = fopen ( "output.dat" , "w" );
		
		size_recv = 500;
		mesg_recv = ( char * ) calloc ( size_recv , sizeof ( char ) );
	
		size_substring = 500;
		substring = ( char * ) calloc ( size_substring , sizeof ( char ) );
		
		size_file_name = 500;
		file_name = ( char * ) calloc ( size_file_name , sizeof ( char ) );
		len_clnt = sizeof ( adr_clnt );
		accept_return = accept ( tcp_socket , ( struct sockaddr * ) &adr_clnt , &len_clnt );
		if ( accept_return == -1 )
		{
			error_report ( "accept() malfunction" );
		}
		recv_return = recv ( accept_return , mesg_recv , 500 ,  0 );
		if ( recv_return == -1 )
		{
			error_report ( "recv() malfunction" );
		}
		i = 0;
		while ( mesg_recv[i] != '#' && mesg_recv[i] != '%' )
		{
			*(substring + j ) = mesg_recv[i];
			j++;
			i++;
			if ( mesg_recv[i] == '#' )
			{
				i++;
				fprintf ( output_file , "%s\n" , substring );
				memset ( substring , 0 , strlen( substring ) );;
				j = 0;
			}
		}
		for ( i = 0 ; i < j ; i++ )
		{
			fprintf ( output_file , "%c" , substring[i] );
		}
		fprintf ( output_file , "%c" , '\n' );
		j = 0;
		fclose ( output_file );
		i = 0;
		for ( i = 0 ; mesg_recv[i] != '\0' ; i++ )
		{
			if ( mesg_recv[i] == '%' )
			{
				i++;
				while ( mesg_recv[i] != '\0' )
				{
					*(file_name + j ) = mesg_recv[i];
					j++;
					i++;
					if ( mesg_recv[i] == '\0' )
					{
						flag = 0;
					}
				}
			}
		if ( flag == 1 )
		{
			break;
		}
	}
	i = 0;
	j = 0;
	write ( accept_return , mesg , strlen ( mesg  ) );
	free ( file_name );
	free ( substring );
	free ( mesg_recv );
	i = 0;
	j = 0;
	flag = 0;
	close ( accept_return );
	}
	return ( EXIT_SUCCESS );
}