#include "Platform.h"

#ifdef RUSH_PLATFORM_LINUX

#include "GfxCommon.h"
#include "GfxDevice.h"
#include "WindowXCB.h"

#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

namespace Rush
{

static Window*     g_mainWindow     = nullptr;
static GfxDevice*  g_mainGfxDevice  = nullptr;
static GfxContext* g_mainGfxContext = nullptr;

Window* Platform_CreateWindow(const WindowDesc& desc) { return new WindowXCB(desc); }

void        Platform_TerminateProcess(int status) { exit(status); }
GfxDevice*  Platform_GetGfxDevice() { return g_mainGfxDevice; }
GfxContext* Platform_GetGfxContext() { return g_mainGfxContext; }
Window*     Platform_GetWindow() { return g_mainWindow; }

const char* Platform_GetExecutableDirectory()
{
	static bool isInitialized = false;
	static char path[4096] = {};

	if (!isInitialized)
	{
		ssize_t writtenBytes = readlink("/proc/self/exe", path, sizeof(path));

		if (writtenBytes < 0)
		{
			RUSH_LOG_ERROR("readlink(\"/proc/self/exe\") failed: %s (%d)", strerror(errno), errno);
			strncpy(path, ".", 2);
		}
		else if (writtenBytes == sizeof(path))
		{
			RUSH_LOG_ERROR("readlink(\"/proc/self/exe\") failed because output buffer is too small");
			strncpy(path, ".", 2);
		}
		else
		{
			size_t lastSlash = 0;
			for (size_t i = 0; i < sizeof(path) && path[i]; ++i)
			{
				if (path[i] == '/')
					lastSlash = i;
			}

			if (lastSlash != 0)
			{
				path[lastSlash] = 0;
			}
		}

		isInitialized = true;
	}

	return path;
}

int Platform_Main(const AppConfig& cfg)
{
	WindowDesc windowDesc;
	windowDesc.width      = cfg.width;
	windowDesc.height     = cfg.height;
	windowDesc.resizable  = cfg.resizable;
	windowDesc.caption    = cfg.name;
	windowDesc.fullScreen = cfg.fullScreen;

	Window* window = Platform_CreateWindow(windowDesc);

	g_mainWindow = window;

	GfxConfig gfxConfig;
	if (cfg.gfxConfig)
	{
		gfxConfig = *cfg.gfxConfig;
	}
	else
	{
		gfxConfig = GfxConfig(cfg);
	}
	g_mainGfxDevice  = Gfx_CreateDevice(window, gfxConfig);
	g_mainGfxContext = Gfx_AcquireContext();

	if (cfg.onStartup)
	{
		cfg.onStartup(cfg.userData);
	}

	while (window->isClosed() == false)
	{
		window->pollEvents();

		Gfx_BeginFrame();

		if (cfg.onUpdate)
		{
			cfg.onUpdate(cfg.userData);
		}

		Gfx_EndFrame();
		Gfx_Present();
	}

	if (cfg.onShutdown)
	{
		cfg.onShutdown(cfg.userData);
	}

	Gfx_Release(g_mainGfxContext);
	Gfx_Release(g_mainGfxDevice);

	window->release();

	return 0;
}
}

#endif