#include <windows.h>
#include <iostream>
#include <strsafe.h>
#define MAX_BUF 256
using namespace std;

int msgCount, pCount;	// messages count, r/w count
TCHAR buf[MAX_BUF] = {0};
HANDLE hMutexR1, hMutexR2, hMutexW1, hMutexW2;	// mutex for maximum 2 current r/w
HANDLE hMsgA, hMsgB;	// msg events
HANDLE hEndW, hEndR;	// end session events

bool getRaW();
bool getMSG();

int main()
{
	if(!getRaW() || !getMSG())	// get r/w and messages
	{
		printf("Incorrect value!\r\n");
		return 0;
	}
	
	//printf("MSG: %d\r\nRaW: %d\r\n", msgCount, pCount);
	hMutexR1 = CreateMutex(NULL, FALSE, L"MutexR1");
	hMutexR2 = CreateMutex(NULL, FALSE, L"MutexR2");
	hMutexW1 = CreateMutex(NULL, FALSE, L"MutexW1");
	hMutexW2 = CreateMutex(NULL, FALSE, L"MutexW2");

	hMsgA = CreateEvent(NULL, TRUE, FALSE, L"MessageA");
	hMsgB = CreateEvent(NULL, TRUE, FALSE, L"MessageB");

	hEndW = CreateEvent(NULL, TRUE, FALSE, L"EndW");
	hEndR = CreateEvent(NULL, TRUE, FALSE, L"EndR");

	StringCbPrintf(buf, MAX_BUF, L"%d", msgCount);	// total msg per session
	SetEnvironmentVariable(L"msgCount", buf);
	
	int i = 0;
	while (i < pCount)	// run r/w count
	{
		i++;
		STARTUPINFO si, si2;	// some vars
		PROCESS_INFORMATION pi, pi2;
		ZeroMemory(&si, sizeof(STARTUPINFO));
		si.cb = sizeof(STARTUPINFO);
		ZeroMemory(&si2, sizeof(STARTUPINFO));
		si2.cb = sizeof(STARTUPINFO);

		// start writer and reader
		if (!CreateProcess(L"Writer.exe", NULL, NULL, NULL, FALSE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi))	 // relative path
		{
			printf("Can't start Writer.exe\r\n");
			return GetLastError();
		}
		
		if (!CreateProcess(L"Reader.exe", NULL, NULL, NULL, FALSE, CREATE_NEW_CONSOLE, NULL, NULL, &si2, &pi2))
		{
			printf("Can't start Reader.exe\r\n");
			return GetLastError();
		}
	}

	// open end session events
	int ends = 0;
	HANDLE hEnd[2];
	hEnd[0] = OpenEvent(EVENT_ALL_ACCESS, FALSE, L"EndW");
	hEnd[1] = OpenEvent(EVENT_ALL_ACCESS, FALSE, L"EndR");

	while (ends < pCount)	// wait all sessions end
	{
		WaitForMultipleObjects(2, hEnd, TRUE, INFINITE);
		ResetEvent(hEnd[0]);	// reset events for next session
		ResetEvent(hEnd[1]);
		ends++;
		printf("Writer and Reader session closed\r\n");
	}
	
	printf("\r\nInput any char to exit...\r\n");
	scanf_s("%d", &pCount);
	
	// close all handles
	CloseHandle(hMutexR1);
	CloseHandle(hMutexR2);
	CloseHandle(hMutexW1);
	CloseHandle(hMutexW2);
	
	CloseHandle(hMsgA);
	CloseHandle(hMsgB);
	CloseHandle(hEndW);
	CloseHandle(hEndR);

	return 0;
}

bool getRaW()
{
	printf("Enter number of Readers/Writers (max 10): ");
	
	if (scanf_s("%d", &pCount) == 0)
		return false;

	if(pCount > 10)
	{
		pCount = 10;
		printf("Number of Readers/Writers set to 10 (max)\r\n");
	}
	
	if(pCount < 1)
	{
		pCount = 1;
		printf("Number of Readers/Writers set to 1 (min)\r\n");
	}

	return true;
}

bool getMSG()
{
	printf("Enter number of messages (max 10): ");
	
	if (scanf_s("%d", &msgCount) == 0)
		return false;

	if(msgCount > 10)
	{
		msgCount = 10;
		printf("Number of messages set to 10 (max)\r\n");
	}
	
	if(msgCount < 1)
	{
		msgCount = 1;
		printf("Number of messages set to 1 (min)\r\n");
	}

	return true;
}