PSI 01

// UDP_Communication_Framework.cpp : Defines the entry point for the console application.
//

#pragma comment(lib, "ws2_32.lib")
#include "stdafx.h"
#include <winsock2.h>
#include "ws2tcpip.h"

#include<iostream>
#include<fstream>
#include<string>
#include<stdlib.h>
using namespace std;

#define TARGET_IP   "127.0.0.1"

#define BUFFERS_LEN 1024

//#define SENDER
#define RECEIVER

#ifdef SENDER
#define TARGET_PORT 5555
#define LOCAL_PORT 8888
#endif // SENDER

#ifdef RECEIVER
#define TARGET_PORT 8888
#define LOCAL_PORT 5555
#endif // RECEIVER

void InitWinsock()
{
	WSADATA wsaData;
	WSAStartup(MAKEWORD(2, 2), &wsaData);
}

// reads number saved as array of chars
int processSize(char* buffer) {
	int ret = 0;
	ret += buffer[0] << 24;
	ret += buffer[1] << 16;
	ret += buffer[2] << 8;
	ret += buffer[3];

	//for (int i = 0; i <= 32; i++) {
//		int tmp = (int)buffer[i] - 48;
		//printf("%d\n", tmp);
//		if (tmp < 10 && tmp >= 0) {
//			ret = ret * 10 + (int)tmp;
//		}
//	}
	return ret;
}

//**********************************************************************
int main()
{
	SOCKET socketS;

	InitWinsock();

	struct sockaddr_in local;
	struct sockaddr_in from;

	int fromlen = sizeof(from);
	local.sin_family = AF_INET;
	local.sin_port = htons(LOCAL_PORT);
	local.sin_addr.s_addr = INADDR_ANY;


	socketS = socket(AF_INET, SOCK_DGRAM, 0);
	if (bind(socketS, (sockaddr*)&local, sizeof(local)) != 0) {
		printf("Binding error!\n");
		getchar(); //wait for press Enter
		return 1;
	}
	//**********************************************************************
	char buffer_rx[BUFFERS_LEN];
	char buffer_tx[BUFFERS_LEN];

#ifdef SENDER

	sockaddr_in addrDest;
	addrDest.sin_family = AF_INET;
	addrDest.sin_port = htons(TARGET_PORT);
	InetPton(AF_INET, _T(TARGET_IP), &addrDest.sin_addr.s_addr);

	int size = 0;
	char name[] = "car.jpg";

	// send file name
	sprintf(buffer_tx, "%s", name);
	printf("Sending name.\n");
	sendto(socketS, buffer_tx, strlen(buffer_tx), 0, (sockaddr*)&addrDest, sizeof(addrDest));

	// open file
	FILE *p_file = fopen(name, "rb");

	// get file size
	fseek(p_file, 0, SEEK_END);
	size = ftell(p_file);
	rewind(p_file);

	// send file size


	buffer_tx[0] = (value >> 24);// &0xFF;
	buffer_tx[1] = (value >> 16);// &0xFF;
	buffer_tx[2] = (value >> 8);// &0xFF;
	buffer_tx[3] = value;// &0xFF;


	// sprintf(buffer_tx, "%d", size);
	printf("Sending size. (%d)\n", size);
	sendto(socketS, buffer_tx, strlen(buffer_tx), 0, (sockaddr*)&addrDest, sizeof(addrDest));

	// read file into memory(buffer)
	char* fileBuffer = (char*)malloc(size);
	fread(fileBuffer, 1, size + 1, p_file);

	printf("\n");

	// send start indicator
	//strncpy(buffer_tx, "START\n", BUFFERS_LEN);
	//sendto(socketS, buffer_tx, strlen(buffer_tx), 0, (sockaddr*)&addrDest, sizeof(addrDest));

	// send file
	int i;
	for (i = 0; i < size / BUFFERS_LEN; i++) {

		memcpy(buffer_tx, fileBuffer + i * BUFFERS_LEN, BUFFERS_LEN);
		printf("Sending packet. (%d)\n", i);
		sendto(socketS, buffer_tx, BUFFERS_LEN, 0, (sockaddr*)&addrDest, sizeof(addrDest));
	}

	// for last packet (can be shorter than BUFFERS_LEN)
	memcpy(buffer_tx, fileBuffer + i * BUFFERS_LEN, size % BUFFERS_LEN);
	printf("Sending last packet.");
	sendto(socketS, buffer_tx, BUFFERS_LEN, 0, (sockaddr*)&addrDest, sizeof(addrDest));

	// send end indicator
	//strncpy(buffer_tx, "END\n", BUFFERS_LEN);
	//sendto(socketS, buffer_tx, strlen(buffer_tx), 0, (sockaddr*)&addrDest, sizeof(addrDest));

	// close file and connection
	fclose(p_file);
	closesocket(socketS);

#endif // SENDER

#ifdef RECEIVER

	int messageLength;
	char name[BUFFERS_LEN];

	// cleans the buffer
	strncpy(buffer_rx, "", BUFFERS_LEN);
	printf("Recieving ...\n");

	// get name
	if (recvfrom(socketS, buffer_rx, sizeof(buffer_rx), 0, (sockaddr*)&from, &fromlen) == SOCKET_ERROR) {
		printf("Header socket error!\n");
		getchar();
		return 1;
	}
	else {
		printf("Name: %s!\n", buffer_rx);
	}
	strcpy(name, buffer_rx);


	// get size
	if (recvfrom(socketS, buffer_rx, sizeof(buffer_rx), 0, (sockaddr*)&from, &fromlen) == SOCKET_ERROR) {
		printf("Header socket error!\n");
		getchar();
		return 1;
	}
	else {




		 messageLength = processSize(buffer_rx);
		printf("Size: %d\n", messageLength);
	}

	// init file
	FILE *p_file = fopen(name, "wb");

	// read whole message
	int i;
	for (i = 0; i < messageLength / BUFFERS_LEN; i++) {

		if (recvfrom(socketS, buffer_rx, BUFFERS_LEN, 0, (sockaddr*)&from, &fromlen) == SOCKET_ERROR) {
			printf("Socket error!\n");
			getchar();
			return 1;
		}
		else {
			printf("Recieving packet: %i\n", i);
			fwrite(buffer_rx, 1, BUFFERS_LEN, p_file);
		}
	}

	// recieve last packet
	if (recvfrom(socketS, buffer_rx, sizeof(buffer_rx), 0, (sockaddr*)&from, &fromlen) == SOCKET_ERROR) {
		printf("Socket error!\n");
		getchar();
		return 1;
	}
	else {
		printf("Recieving last packet.");
		fwrite(buffer_rx, 1, messageLength % BUFFERS_LEN, p_file);
	}

	// close file and connection
	fclose(p_file);
	closesocket(socketS);

#endif
	//**********************************************************************

	getchar(); //wait for press Enter
	return 0;
}