/*
 * WindowHandler.cpp, part of VCMI engine
 *
 * Authors: listed in file AUTHORS in main folder
 *
 * License: GNU General Public License v2.0 or later
 * Full text of license available in license.txt file, in main folder
 *
 */

#include "StdInc.h"
#include "WindowHandler.h"

#include "../../lib/CConfigHandler.h"
#include "../gui/CGuiHandler.h"
#include "../gui/NotificationHandler.h"
#include "CMT.h"
#include "SDL_Extensions.h"

#ifdef VCMI_ANDROID
#include "../lib/CAndroidVMHelper.h"
#endif

#include <SDL.h>

SDL_Window * mainWindow = nullptr;
SDL_Renderer * mainRenderer = nullptr;
SDL_Texture * screenTexture = nullptr;
SDL_Surface * screen = nullptr; //main screen surface
SDL_Surface * screen2 = nullptr; //and hlp surface (used to store not-active interfaces layer)
SDL_Surface * screenBuf = screen; //points to screen (if only advmapint is present) or screen2 (else) - should be used when updating controls which are not regularly redrawed

static const std::string NAME_AFFIX = "client";
static const std::string NAME = GameConstants::VCMI_VERSION + std::string(" (") + NAME_AFFIX + ')'; //application name

Point WindowHandler::getPreferredLogicalResolution() const
{
	// TODO: CONFIGURABLE ADVMAP - IMPLEMENT UI SCALE SETTING
	return {1280, 720};
}

Point WindowHandler::getPreferredRenderingResolution() const
{
	if (getPreferredWindowMode() == EWindowMode::FULLSCREEN_WINDOWED)
	{
		SDL_Rect bounds;
		SDL_GetDisplayBounds(getPreferredDisplayIndex(), &bounds);
		return Point(bounds.w, bounds.h);
	}
	else
	{
		const JsonNode & video = settings["video"];
		int width = video["screenRes"]["width"].Integer();
		int height = video["screenRes"]["height"].Integer();

		return Point(width, height);
	}
}

int WindowHandler::getPreferredDisplayIndex() const
{
#ifdef VCMI_MOBILE
	// Assuming no multiple screens on Android / ios?
	return 0;
#else
	if (mainWindow != nullptr)
		return SDL_GetWindowDisplayIndex(mainWindow);
	else
		return settings["video"]["displayIndex"].Integer();
#endif
}

EWindowMode WindowHandler::getPreferredWindowMode() const
{
#ifdef VCMI_MOBILE
	// On Android / ios game will always render to screen size
	return EWindowMode::FULLSCREEN_WINDOWED;
#else
	const JsonNode & video = settings["video"];
	bool fullscreen = video["fullscreen"].Bool();
	bool realFullscreen = settings["video"]["realFullscreen"].Bool();

	if (!fullscreen)
		return EWindowMode::WINDOWED;

	if (realFullscreen)
		return EWindowMode::FULLSCREEN_TRUE;
	else
		return EWindowMode::FULLSCREEN_WINDOWED;
#endif
}

WindowHandler::WindowHandler()
{
	if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_AUDIO | SDL_INIT_NOPARACHUTE))
	{
		logGlobal->error("Something was wrong: %s", SDL_GetError());
		exit(-1);
	}

	const auto & logCallback = [](void * userdata, int category, SDL_LogPriority priority, const char * message)
	{
		logGlobal->debug("SDL(category %d; priority %d) %s", category, priority, message);
	};

	SDL_LogSetOutputFunction(logCallback, nullptr);

#ifdef VCMI_ANDROID
	// manually setting egl pixel format, as a possible solution for sdl2<->android problem
	// https://bugzilla.libsdl.org/show_bug.cgi?id=2291
	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 6);
	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
#endif // VCMI_ANDROID

	validateSettings();
	recreateWindow();
}

bool WindowHandler::recreateWindow()
{
	destroyScreen();

	if(mainWindow == nullptr)
		initializeRenderer();
	else
		updateFullscreenState();

	initializeScreen();

	if(!settings["session"]["headless"].Bool() && settings["general"]["notifications"].Bool())
	{
		NotificationHandler::init(mainWindow);
	}

	return true;
}

void WindowHandler::updateFullscreenState()
{
#if !defined(VCMI_MOBILE)
	int displayIndex = getPreferredDisplayIndex();

	switch(getPreferredWindowMode())
	{
		case EWindowMode::FULLSCREEN_TRUE:
		{
			SDL_SetWindowFullscreen(mainWindow, SDL_WINDOW_FULLSCREEN);

			SDL_DisplayMode mode;
			SDL_GetDesktopDisplayMode(displayIndex, &mode);
			Point resolution = getPreferredRenderingResolution();

			mode.w = resolution.x;
			mode.h = resolution.y;

			SDL_SetWindowDisplayMode(mainWindow, &mode);
			SDL_SetWindowPosition(mainWindow, SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex), SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex));

			return;
		}
		case EWindowMode::FULLSCREEN_WINDOWED:
		{
			SDL_SetWindowFullscreen(mainWindow, SDL_WINDOW_FULLSCREEN_DESKTOP);
			SDL_SetWindowPosition(mainWindow, SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex), SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex));
			return;
		}
		case EWindowMode::WINDOWED:
		{
			Point resolution = getPreferredLogicalResolution();
			SDL_SetWindowFullscreen(mainWindow, 0);
			SDL_SetWindowSize(mainWindow, resolution.x, resolution.y);
			SDL_SetWindowPosition(mainWindow, SDL_WINDOWPOS_CENTERED_DISPLAY(displayIndex), SDL_WINDOWPOS_CENTERED_DISPLAY(displayIndex));
			return;
		}
	}
#endif
}

void WindowHandler::initializeRenderer()
{
	mainWindow = createWindow();

	if(mainWindow == nullptr)
		throw std::runtime_error("Unable to create window\n");

	//create first available renderer if preferred not set. Use no flags, so HW accelerated will be preferred but SW renderer also will possible
	mainRenderer = SDL_CreateRenderer(mainWindow, getPreferredRenderingDriver(), 0);

	if(mainRenderer == nullptr)
		throw std::runtime_error("Unable to create renderer\n");

	SDL_RendererInfo info;
	SDL_GetRendererInfo(mainRenderer, &info);
	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "best");
	logGlobal->info("Created renderer %s", info.name);
}

void WindowHandler::initializeScreen()
{
#ifdef VCMI_ENDIAN_BIG
	int bmask = 0xff000000;
	int gmask = 0x00ff0000;
	int rmask = 0x0000ff00;
	int amask = 0x000000ff;
#else
	int bmask = 0x000000ff;
	int gmask = 0x0000ff00;
	int rmask = 0x00ff0000;
	int amask = 0xFF000000;
#endif

	auto logicalSize = getPreferredLogicalResolution();
	SDL_RenderSetLogicalSize(mainRenderer, logicalSize.x, logicalSize.y);

	screen = SDL_CreateRGBSurface(0, logicalSize.x, logicalSize.y, 32, rmask, gmask, bmask, amask);
	if(nullptr == screen)
	{
		logGlobal->error("Unable to create surface %dx%d with %d bpp: %s", logicalSize.x, logicalSize.y, 32, SDL_GetError());
		throw std::runtime_error("Unable to create surface");
	}
	//No blending for screen itself. Required for proper cursor rendering.
	SDL_SetSurfaceBlendMode(screen, SDL_BLENDMODE_NONE);

	screenTexture = SDL_CreateTexture(mainRenderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, logicalSize.x, logicalSize.y);

	if(nullptr == screenTexture)
	{
		logGlobal->error("Unable to create screen texture");
		logGlobal->error(SDL_GetError());
		throw std::runtime_error("Unable to create screen texture");
	}

	screen2 = CSDL_Ext::copySurface(screen);

	if(nullptr == screen2)
	{
		throw std::runtime_error("Unable to copy surface\n");
	}

	screenBuf = screen;
	clearScreen();
}

SDL_Window * WindowHandler::createWindowImpl(Point dimensions, int flags, bool center)
{
	int displayIndex = getPreferredDisplayIndex();
	int positionFlags = center ? SDL_WINDOWPOS_CENTERED_DISPLAY(displayIndex) : SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex);

	return SDL_CreateWindow(NAME.c_str(), positionFlags, positionFlags, dimensions.x, dimensions.y, flags);
}

SDL_Window * WindowHandler::createWindow()
{
#ifndef VCMI_MOBILE
	Point dimensions = getPreferredRenderingResolution();

	switch(getPreferredWindowMode())
	{
		case EWindowMode::FULLSCREEN_TRUE:
			return createWindowImpl(dimensions, SDL_WINDOW_FULLSCREEN, false);

		case EWindowMode::FULLSCREEN_WINDOWED:
			return createWindowImpl(Point(), SDL_WINDOW_FULLSCREEN_DESKTOP, false);

		case EWindowMode::WINDOWED:
			return createWindowImpl(dimensions, 0, true);

		default:
			return nullptr;
	};
#endif

#ifdef VCMI_IOS
	SDL_SetHint(SDL_HINT_IOS_HIDE_HOME_INDICATOR, "1");
	SDL_SetHint(SDL_HINT_RETURN_KEY_HIDES_IME, "1");
	SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "best");

	uint32_t windowFlags = SDL_WINDOW_BORDERLESS | SDL_WINDOW_ALLOW_HIGHDPI;
	SDL_Window * result = createWindowImpl(Point(), windowFlags | SDL_WINDOW_METAL, false);

	if(result != nullptr)
		return result;

	logGlobal->warn("Metal unavailable, using OpenGLES");
	return createWindowImpl(Point(), windowFlags, false);
#endif

#ifdef VCMI_ANDROID
	return createWindowImpl(Point(), SDL_WINDOW_FULLSCREEN, false);
#endif
}

void WindowHandler::onFullscreenChanged()
{
	if(!recreateWindow())
	{
		//will return false and report error if video mode is not supported
		return;
	}
	GH.totalRedraw();
}

void WindowHandler::validateSettings()
{
#if !defined(VCMI_MOBILE)
	{
		int displayIndex = settings["video"]["displayIndex"].Integer();
		int displaysCount = SDL_GetNumVideoDisplays();

		if (displayIndex >= displaysCount)
		{
			Settings writer = settings.write["video"]["displayIndex"];
			writer->Float() = 0;
		}
	}

	if (getPreferredWindowMode() == EWindowMode::WINDOWED)
	{
		//we only check that our desired window size fits on screen
		int displayIndex = getPreferredDisplayIndex();
		Point resolution = getPreferredRenderingResolution();

		SDL_DisplayMode mode;

		if (SDL_GetDesktopDisplayMode(displayIndex, &mode) == 0)
		{
			if(resolution.x > mode.w || resolution.y > mode.h)
			{
				Settings writer = settings.write["video"]["screenRes"];
				writer["width"].Float() = mode.w;
				writer["height"].Float() = mode.h;
			}
		}
	}

	if (getPreferredWindowMode() == EWindowMode::FULLSCREEN_TRUE)
	{
		// TODO: check that display supports selected resolution
	}
#endif
}

int WindowHandler::getPreferredRenderingDriver() const
{
	int result = -1;
	const JsonNode & video = settings["video"];

	int driversCount = SDL_GetNumRenderDrivers();
	std::string preferredDriverName = video["driver"].String();

	logGlobal->info("Found %d render drivers", driversCount);

	for(int it = 0; it < driversCount; it++)
	{
		SDL_RendererInfo info;
		SDL_GetRenderDriverInfo(it, &info);

		std::string driverName(info.name);

		if(!preferredDriverName.empty() && driverName == preferredDriverName)
		{
			result = it;
			logGlobal->info("\t%s (active)", driverName);
		}
		else
			logGlobal->info("\t%s", driverName);
	}
	return result;
}

void WindowHandler::destroyScreen()
{
	screenBuf = nullptr; //it`s a link - just nullify

	if(nullptr != screen2)
	{
		SDL_FreeSurface(screen2);
		screen2 = nullptr;
	}

	if(nullptr != screen)
	{
		SDL_FreeSurface(screen);
		screen = nullptr;
	}

	if(nullptr != screenTexture)
	{
		SDL_DestroyTexture(screenTexture);
		screenTexture = nullptr;
	}
}

void WindowHandler::destroyWindow()
{
	if(nullptr != mainRenderer)
	{
		SDL_DestroyRenderer(mainRenderer);
		mainRenderer = nullptr;
	}

	if(nullptr != mainWindow)
	{
		SDL_DestroyWindow(mainWindow);
		mainWindow = nullptr;
	}
}

void WindowHandler::close()
{
	if(settings["general"]["notifications"].Bool())
		NotificationHandler::destroy();

	destroyScreen();
	destroyWindow();
	SDL_Quit();
}

void WindowHandler::clearScreen()
{
	SDL_SetRenderDrawColor(mainRenderer, 0, 0, 0, 255);
	SDL_RenderClear(mainRenderer);
	SDL_RenderPresent(mainRenderer);
}