#include <node.h>
#include <windows.h>
#include <TlHelp32.h>
#include <vector>
#include "process.hpp"
#include "memoryjs.hpp"

process::process() {}
process::~process() {}

using v8::Exception;
using v8::Isolate;
using v8::String;

process::Pair process::openProcess(const char *processName, char **errorMessage)
{
	PROCESSENTRY32 process;
	HANDLE handle = NULL;

	// A list of processes (PROCESSENTRY32)
	std::vector<PROCESSENTRY32> processes = getProcesses(errorMessage);

	for (std::vector<PROCESSENTRY32>::size_type i = 0; i != processes.size(); i++)
	{
		// Check to see if this is the process we want.
		if (!strcmp(processes[i].szExeFile, processName))
		{
			handle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, processes[i].th32ProcessID);
			process = processes[i];
			break;
		}
	}

	if (handle == NULL)
	{
		*errorMessage = "unable to find process";
	}

	return {
		handle,
		process,
	};
}

process::Pair process::openProcess(DWORD processId, char **errorMessage)
{
	PROCESSENTRY32 process;
	HANDLE handle = NULL;

	// A list of processes (PROCESSENTRY32)
	std::vector<PROCESSENTRY32> processes = getProcesses(errorMessage);

	for (std::vector<PROCESSENTRY32>::size_type i = 0; i != processes.size(); i++)
	{
		// Check to see if this is the process we want.
		if (processId == processes[i].th32ProcessID)
		{
			handle = OpenProcess(PROCESS_ALL_ACCESS, FALSE, processes[i].th32ProcessID);
			process = processes[i];
			break;
		}
	}

	if (handle == NULL)
	{
		*errorMessage = "unable to find process";
	}

	return {
		handle,
		process,
	};
}

void process::closeProcess(HANDLE hProcess)
{
	CloseHandle(hProcess);
}

std::vector<PROCESSENTRY32> process::getProcesses(char **errorMessage)
{
	// Take a snapshot of all processes.
	HANDLE hProcessSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, NULL);
	PROCESSENTRY32 pEntry;

	if (hProcessSnapshot == INVALID_HANDLE_VALUE)
	{
		*errorMessage = "method failed to take snapshot of the process";
	}

	// Before use, set the structure size.
	pEntry.dwSize = sizeof(pEntry);

	// Exit if unable to find the first process.
	if (!Process32First(hProcessSnapshot, &pEntry))
	{
		CloseHandle(hProcessSnapshot);
		*errorMessage = "method failed to retrieve the first process";
	}

	std::vector<PROCESSENTRY32> processes;

	// Loop through processes.
	do
	{
		// Add the process to the vector
		processes.push_back(pEntry);
	} while (Process32Next(hProcessSnapshot, &pEntry));

	CloseHandle(hProcessSnapshot);
	return processes;
}