#if defined(_WIN32) || defined(_WIN64)
#include "uniproc.h"
#include <Windows.h>
#include <fcntl.h>
#include <io.h>

uniproc_process uniproc_create_process(const char* cmd, const size_t num_args, const char** argv)
{
	// Create pipes
	HANDLE child_in;
	HANDLE in;
	HANDLE child_out;
	HANDLE out;
	HANDLE child_err;
	HANDLE err;
	
	SECURITY_ATTRIBUTES pipe_attribs;
	pipe_attribs.nLength = sizeof(SECURITY_ATTRIBUTES);
	pipe_attribs.bInheritHandle = 1;
	pipe_attribs.lpSecurityDescriptor = NULL;

	// Actually create the pipes
	if (!CreatePipe(&out, &child_out, &pipe_attribs, 0))
	{
		uniproc_nullify_processes(p, 1);
		return p;
	}
	if (!CreatePipe(&err, &child_err, &pipe_attribs, 0))
	{
		CloseHandle(child_out);
		CloseHandle(out);
		uniproc_nullify_processes(p, 1);
		return p;
	}
	if (!CreatePipe(&child_in, &in, &pipe_attribs, 0))
	{
		CloseHandle(child_out);
		CloseHandle(out);
		CloseHandle(child_err);
		CloseHandle(err);
		uniproc_nullify_processes(p, 1);
		return p;
	}

	// Unset inherrit flags for the pipes
	if (!SetHandleInformation(out, HANDLE_FLAG_INHERIT, 0))
	{
		CloseHandle(child_in);
		CloseHandle(in);
		CloseHandle(child_out);
		CloseHandle(out);
		CloseHandle(child_err);
		CloseHandle(err);
		uniproc_nullify_processes(p, 1);
		return p;
	}
	if (!SetHandleInformation(err, HANDLE_FLAG_INHERIT, 0))
	{
		CloseHandle(child_in);
		CloseHandle(in);
		CloseHandle(child_out);
		CloseHandle(out);
		CloseHandle(child_err);
		CloseHandle(err);
		uniproc_nullify_processes(p, 1);
		return p;
	}
	if (!SetHandleInformation(in, HANDLE_FLAG_INHERIT, 0))
	{
		CloseHandle(child_in);
		CloseHandle(in);
		CloseHandle(child_out);
		CloseHandle(out);
		CloseHandle(child_err);
		CloseHandle(err);
		uniproc_nullify_processes(p, 1);
		return p;
	}

	// Create child process
	uniproc_process p;

	// Create p_cmd by appending all argv's to cmd
	size_t x = strlen(cmd);
	size_t cmd_len = x + 1;
	for (size_t i = 0; i < num_args; ++i)
		cmd_len += strlen(argv[i]) + 1;
	char* p_cmd = malloc((cmd_len+1) * sizeof(char));
	p_cmd[x] = ' ';
	memcpy(p_cmd, cmd, x * sizeof(char));
	x += 1; // Account for space after cmd
	for (size_t i = 0; i < num_args; ++i)
	{
		size_t arglen = strlen(argv[i]);
		memcpy(p_cmd + x, argv[i], arglen);
		p_cmd[x + arglen] = ' ';
		x += arglen + 1;
	}
	p_cmd[cmd_len] = '\0';

	PROCESS_INFORMATION p_info;
	STARTUPINFOA p_startup;
	memset(&p_info, 0, sizeof(PROCESS_INFORMATION));
	memset(&p_startup, 0, sizeof(STARTUPINFOA));

	p_startup.cb = sizeof(STARTUPINFOA);
	p_startup.dwFlags |= STARTF_USESTDHANDLES;
	p_startup.hStdInput = child_in;
	p_startup.hStdOutput = child_out;
	p_startup.hStdError = child_err;

	int is_ok = CreateProcessA(
		NULL,// Application name
		p_cmd,	// Command to execute
		NULL,// Security attributes
		NULL,// Primary thread security
		1,		// Inherrit handles
		0,	// Creation flags
		NULL,// Environment (use parent's)
		NULL,// Current directory (use parent's)
		&p_startup,
		&p_info
	);
	free(p_cmd);

	if (!is_ok)
	{
		CloseHandle(child_in);
		CloseHandle(in);
		CloseHandle(child_out);
		CloseHandle(out);
		CloseHandle(child_err);
		CloseHandle(err);
		uniproc_nullify_processes(p, 1);
		return p;
	}

	p.err = _fdopen(_open_osfhandle((intptr_t)err, _O_RDONLY), "r");
	p.out = _fdopen(_open_osfhandle((intptr_t)out, _O_RDONLY), "r");
	p.in = _fdopen(_open_osfhandle( (intptr_t)in, _O_WRONLY), "w");
	p._proc_hdl		= (uint32_t)p_info.hProcess;

	CloseHandle(child_in);
	CloseHandle(child_out);
	CloseHandle(child_err);
	CloseHandle(p_info.hThread);

	return p;
}

void uniproc_await_processes(uniproc_process* p, int* return_codes, size_t num_processes)
{
	size_t num_valid_handles = 0;
	HANDLE* h = (HANDLE*)malloc(num_processes*sizeof(HANDLE));
	for (size_t i = 0; i < num_processes; ++i)
	{
		if (uniproc_is_process_null(p + i)) continue;
		h[i] = (HANDLE)p[i]._proc_hdl;
		num_valid_handles++;
	}

	WaitForMultipleObjects(num_valid_handles, h, 1, INFINITE);
	free(h);

	if (return_codes == NULL) return;
	for (size_t i = 0; i < num_processes; ++i)
	{
		if (uniproc_is_process_null(p + i)) continue;
		GetExitCodeProcess((HANDLE)p[i]._proc_hdl, (LPDWORD)(return_codes + i));
	}
}

void uniproc_close_process(uniproc_process* p)
{
	if (uniproc_is_process_null(p)) return;
	TerminateProcess((HANDLE)p->_proc_hdl, 2);
	CloseHandle((HANDLE)p->_proc_hdl);
	fclose(p->in);
	fclose(p->out);
	fclose(p->err);
	uniproc_nullify_processes(p, 1);
}

bool uniproc_are_processes_finished(const uniproc_process* p, const size_t num_processes)
{
	HANDLE* h = (HANDLE*)malloc(num_processes*sizeof(HANDLE));
	size_t num_valid_handles = 0;
	for (size_t i = 0; i < num_processes; ++i)
	{
		if (uniproc_is_process_null(p + i)) continue;
		h[i] = (HANDLE)p[i]._proc_hdl;
		num_valid_handles++;
	}
	DWORD ret = WaitForMultipleObjects(num_valid_handles, h, true, 0);
	free(h);
	return ret >= WAIT_OBJECT_0 && ret < WAIT_OBJECT_0 + num_valid_handles;
}

void uniproc_nullify_processes(uniproc_process* p, const size_t num_processes)
{ memset(p, 0, num_processes * sizeof(uniproc_process)); }

void uniproc_is_process_null(const uniproc_process* p)
{ return p->_proc_hdl == NULL; }

void uniproc_await_any_processes(const uniproc_process* p, const size_t num_processes)
{
	HANDLE* h = (HANDLE*)malloc(num_processes * sizeof(HANDLE));
	size_t num_valid_handles = 0;
	for (size_t i = 0; i < num_processes; ++i)
	{
		if (uniproc_is_process_null(p + i)) continue;
		h[i] = (HANDLE)p[i]._proc_hdl;
		num_valid_handles++;
	}
	WaitForMultipleObjects(num_valid_handles, h, false, INFINITE);
	free(h);
}

void uniproc_set_userdata(uniproc_process * p, void const* userdata)
{ p->userdata = (uint64_t)userdata; }

void* uniproc_get_userdata(uniproc_process* p)
{ return (void*)p->userdata; }

#endif