#include "LuaEngine.h"
#include <iostream>
#include <string>
#include <vector>
#include "SDL2/include/SDL.h"
#include "SDL2/include/SDL_mixer.h"
#include "SDL2/include/SDL_ttf.h"
#include "SDL2/include/SDL_image.h"
#include "PlatAPI.h"
using namespace std;

void check(lua_State* L, const vector<int>& typearr)
{
	int sz = typearr.size();
	for (int i = 0; i < sz; i++)
	{
		if (lua_type(L, i + 1) != typearr[i])
		{
			luaL_error(L, "Bad argument #%d. %s expected, got %s", i + 1, lua_typename(L, typearr[i]), lua_typename(L, lua_type(L, i + 1)));
		}
	}
}

struct LuaTimerCallbackData
{
	void* p;
	int id;
	int type; // 0=setTimeout, 1=setInterval
};

Uint32 LuaTimerCallbackGate(Uint32 interval, void* param)
{
	SDL_Event e;
	e.type = SDL_USEREVENT;
	e.user.code = 1001;
	e.user.data1 = param;
	SDL_PushEvent(&e);
	return ((LuaTimerCallbackData*)(param))->type ? interval : 0;
}

#define setfn(L, cfunc, name) lua_pushcfunction(L, cfunc); lua_setfield(L, -2, name)

struct Window
{
	SDL_Window* wnd;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Window::close" << endl;
		Window* p = (Window*)lua_touserdata(L, 1);
		if (p->wnd)
		{
			// release data table
			lua_pushlightuserdata(L, p);
			lua_pushnil(L);
			lua_settable(L, LUA_REGISTRYINDEX);
			SDL_DestroyWindow(p->wnd);
			p->wnd = nullptr;
		}
		return 0;
	}

	static int start(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		Window* p = (Window*)lua_touserdata(L, 1);
		lua_settop(L, 1);
		lua_pushlightuserdata(L, p);
		lua_gettable(L, LUA_REGISTRYINDEX);

		bool running = true;

		SDL_Event e;
		while (running && SDL_WaitEvent(&e))
		{
			switch (e.type)
			{
			case SDL_MOUSEBUTTONDOWN:
			{
				if (lua_getfield(L, -1, "onclick") != LUA_TNIL)
				{
					lua_pushnumber(L, e.button.x);
					lua_pushnumber(L, e.button.y);
					lua_call(L, 2, LUA_MULTRET);
				}
				else lua_pop(L, 1);
				break;
			}
			case SDL_QUIT:
			{
				if (lua_getfield(L, -1, "onquit") != LUA_TNIL)
				{
					lua_call(L, 0, LUA_MULTRET);
				}
				else lua_pop(L, 1);
				running = 0;
				break;
			}
			case SDL_KEYDOWN:
			{
				if (lua_getfield(L, -1, "onkeydown") != LUA_TNIL)
				{
					lua_pushnumber(L, e.key.keysym.sym);
					lua_call(L, 1, LUA_MULTRET);
				}
				else lua_pop(L, 1);
				break;
			}
			case SDL_USEREVENT:
			{
				switch (e.user.code)
				{
				case 1001:
				{
					LuaTimerCallbackData* pd = (LuaTimerCallbackData* )e.user.data1;
					lua_pushlightuserdata(L, pd->p);
					lua_gettable(L, LUA_REGISTRYINDEX);
					lua_pushfstring(L, "tmcb%d", pd->id);
					lua_gettable(L, -2);
					delete pd;
					lua_call(L, 0, LUA_MULTRET);
					lua_pop(L, 1);
					break;
				}
				}
				break;
			}
			}
		}

		return 0;
	}

	static int set_event_handler(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TSTRING, LUA_TFUNCTION });
		Window* p = (Window*)lua_touserdata(L, 1);
		lua_pushlightuserdata(L, p);
		lua_gettable(L, LUA_REGISTRYINDEX);
		lua_pushfstring(L, "on%s", lua_tostring(L, 2));
		lua_pushvalue(L, 3);
		lua_settable(L, -3);
		return 0;
	}

	static int setTimeout(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TFUNCTION, LUA_TNUMBER }); // ms
		Window* p = (Window*)lua_touserdata(L, 1);

		LuaTimerCallbackData* pd = new LuaTimerCallbackData();
		pd->p = p;
		pd->type = 0;
		pd->id = SDL_AddTimer(lua_tointeger(L, 3), LuaTimerCallbackGate, pd);

		lua_pushlightuserdata(L, p);
		lua_gettable(L, LUA_REGISTRYINDEX);
		lua_pushfstring(L, "tmcb%d", pd->id);
		lua_pushvalue(L, 2);
		lua_settable(L, -3);
		return 0;
	}
	
	static int create(lua_State* L)
	{
		check(L, { LUA_TSTRING, LUA_TNUMBER, LUA_TNUMBER });
		cout << "In Window::create" << endl;
		Window* p = (Window*) lua_newuserdata(L, sizeof(Window));
		// Data table (for storing lua values)
		lua_pushlightuserdata(L, p);
		lua_newtable(L);
		lua_settable(L, LUA_REGISTRYINDEX);
		// Metatable
		lua_getfield(L, LUA_REGISTRYINDEX, "__window_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "window"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");
			setfn(L, set_event_handler, "on");
			setfn(L, start, "start");
			setfn(L, setTimeout, "setTimeout");

			// Binding
			lua_setfield(L, -2, "__index");
			
			lua_setfield(L, LUA_REGISTRYINDEX, "__window_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__window_mt");
		}
		lua_setmetatable(L, -2);

		// Internal logic
		p->wnd = SDL_CreateWindow(lua_tostring(L, 1), SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, lua_tointeger(L, 2), lua_tointeger(L, 3), SDL_WINDOW_SHOWN);
		return 1;
	}
};


struct Texture
{
	SDL_Texture* text;
	int w;
	int h;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Texture::close" << endl;
		Texture* t = (Texture*)lua_touserdata(L, 1);
		if (t->text)
		{
			SDL_DestroyTexture(t->text);
			t->text = nullptr;
		}
		return 0;
	}

	static void create(lua_State* L) // -2, +1
	{
		// 此函数由Renderer在C层直接调用. 调用前需要先放一个renderer userdata和lightuserdata在栈上, 值就是当前的SDL_Texture.
		// 调用后栈上会留下Texture的userdata.
		// 因此在Lua层没有直接创建Texture的方法.
		cout << "In Texture::create" << endl;
		Texture* p = (Texture*)lua_newuserdata(L, sizeof(Texture));
		// Metatable
		lua_getfield(L, LUA_REGISTRYINDEX, "__texture_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "texture"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");

			// Binding
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__texture_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__texture_mt");
		}
		lua_setmetatable(L, -2);
		p->text = (SDL_Texture * )lua_touserdata(L, -2);
		SDL_QueryTexture(p->text, NULL, NULL, &p->w, &p->h);
		lua_pushvalue(L, -3);
		lua_setuservalue(L, -2);   // 绑定这个Rendere userdata

		// stack balance
		lua_remove(L, lua_gettop(L) - 1); // 删除lightuserdata
		lua_remove(L, lua_gettop(L) - 1); // 删除rendere userdata
	}
};

int LuaRectPointToRect(lua_State* L, int index, SDL_Rect& rect)
{
	if (lua_getfield(L, index, "type") != LUA_TSTRING)
	{
		lua_pop(L, 1);
		return -1;
	}

	const char* type = lua_tostring(L, -1);
	if (strcmp(type, "point") == 0)
	{
		lua_pop(L, 1);
		lua_getfield(L, index, "x");
		rect.x = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "y");
		rect.y = lua_tointeger(L, -1);
		lua_pop(L, 1);

		return 1;
	}
	else if (strcmp(type, "rect") == 0)
	{
		lua_pop(L, 1);
		lua_getfield(L, index, "x");
		rect.x = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "y");
		rect.y = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "w");
		rect.w = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "h");
		rect.h = lua_tointeger(L, -1);
		lua_pop(L, 1);

		return 0;
	}
	else
	{
		return -1;
	}
}

struct Surface
{
	SDL_Surface* surf;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Surface::close" << endl;
		Surface* p = (Surface*)lua_touserdata(L, 1);
		if (p->surf)
		{
			SDL_FreeSurface(p->surf);
			p->surf = nullptr;
		}
		return 0;
	}

	static void create(lua_State* L) // -1, +1
	{
		cout << "In Surface::create" << endl;
		Surface* p = (Surface*)lua_newuserdata(L, sizeof(Surface));
		// Metatable
		lua_getfield(L, LUA_REGISTRYINDEX, "__surface_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "surface"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");

			// Binding
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__surface_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__surface_mt");
		}
		lua_setmetatable(L, -2);
		p->surf = (SDL_Surface*)lua_touserdata(L, -2);

		// stack balance
		lua_remove(L, lua_gettop(L) - 1); // 删除lightuserdata
	}
};

struct Renderer
{
	SDL_Renderer* rnd;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Renderer::close" << endl;
		Renderer* p = (Renderer*)lua_touserdata(L, 1);
		if (p->rnd)
		{
			SDL_DestroyRenderer(p->rnd);
			p->rnd = nullptr;
		}
		return 0;
	}

	static int update(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		Renderer* p = (Renderer*)lua_touserdata(L, 1);
		SDL_RenderPresent(p->rnd);
		return 0;
	}

	static int clear(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		Renderer* p = (Renderer*)lua_touserdata(L, 1);
		SDL_RenderClear(p->rnd);
		return 0;
	}

	static int loadTexture(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TSTRING });
		Renderer* p = (Renderer*)lua_touserdata(L, 1);
		const char* filepath = lua_tostring(L, 2);
		SDL_Texture* text = IMG_LoadTexture(p->rnd, filepath);
		lua_pushvalue(L, 1);
		lua_pushlightuserdata(L, text);
		Texture::create(L);
		return 1;
	}

	static int copy(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TTABLE, LUA_TTABLE });
		Renderer* p = (Renderer*)lua_touserdata(L, 1);

		return 0;
	}

	static int copyTo(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TTABLE });
		Renderer* r = (Renderer*)lua_touserdata(L, 1);
		Texture* t = (Texture*)lua_touserdata(L, 2);
		SDL_Rect rect;
		int ret = LuaRectPointToRect(L, 3, rect);
		if (ret < 0)
		{
			luaL_error(L, "Bad argument #%d. Point or Rect expected, got %s", 3, lua_typename(L, lua_type(L, 3)));
		}
		if (ret == 1)
		{
			rect.w = t->w;
			rect.h = t->h;
		}
		SDL_RenderCopy(r->rnd, t->text, NULL, &rect);
		return 0;
	}

	static int create(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Renderer::create" << endl;
		Renderer* p = (Renderer*)lua_newuserdata(L, sizeof(Renderer));
		lua_getfield(L, LUA_REGISTRYINDEX, "__renderer_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "renderer"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");
			setfn(L, update, "update");
			setfn(L, clear, "clear");
			setfn(L, loadTexture, "loadTexture");
			setfn(L, copy, "copy");
			setfn(L, copyTo, "copyTo");

			// Set __index of metatable.
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__renderer_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__renderer_mt");
		}
		lua_setmetatable(L, -2);
		// 绑定当前Renderer的对象到自身, 防止SDL_Window被提前销毁.
		lua_pushvalue(L, 1);
		lua_setuservalue(L, -2);
		// Internal logic
		p->rnd = SDL_CreateRenderer(static_cast<Window*>(lua_touserdata(L, 1))->wnd, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_TARGETTEXTURE);
		return 1;
	}
};

int LuaColorToColor(lua_State* L, int index, SDL_Color& c)
{
	if (lua_getfield(L, index, "type") != LUA_TSTRING)
	{
		lua_pop(L, 1);
		return -1;
	}

	const char* type = lua_tostring(L, -1);
	if (strcmp(type, "color") == 0)
	{
		lua_pop(L, 1);
		lua_getfield(L, index, "r");
		c.r = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "g");
		c.g = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "b");
		c.b = lua_tointeger(L, -1);
		lua_pop(L, 1);
		lua_getfield(L, index, "a");
		c.a = lua_tointeger(L, -1);
		lua_pop(L, 1);

		return 0;
	}
	else
	{
		return -1;
	}
}

struct Font
{
	TTF_Font* font;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Font::close" << endl;
		Font* f = (Font*)lua_touserdata(L, 1);
		if (f->font)
		{
			TTF_CloseFont(f->font);
			f->font = nullptr;
		}
		return 0;
	}

	static int renderText(lua_State* L)
	{
		Renderer* r = nullptr;
		Font* f = nullptr;
		const char* text = nullptr;
		SDL_Color c;
		if (lua_gettop(L) >= 4)
		{
			check(L, { LUA_TUSERDATA, LUA_TUSERDATA, LUA_TSTRING, LUA_TTABLE });
			f = (Font*)lua_touserdata(L, 1);
			r = (Renderer*)lua_touserdata(L, 2);
			text = lua_tostring(L, 3);
			if (LuaColorToColor(L, 4, c) < 0)
			{
				luaL_error(L, "Bad argument #%d. Color expected, got %s", 4, lua_typename(L, lua_type(L, 4)));
			}
		}
		else
		{
			check(L, { LUA_TUSERDATA, LUA_TSTRING, LUA_TTABLE });
			f = (Font*)lua_touserdata(L, 1);
			text = lua_tostring(L, 3);
			if (LuaColorToColor(L, 4, c) < 0)
			{
				luaL_error(L, "Bad argument #%d. Color expected, got %s", 4, lua_typename(L, lua_type(L, 4)));
			}
		}

		SDL_Surface* surf = TTF_RenderText_Blended(f->font, text, c);

		if (r)
		{
			SDL_Texture* text = SDL_CreateTextureFromSurface(r->rnd, surf);
			SDL_FreeSurface(surf);
			lua_pushvalue(L, 2);
			lua_pushlightuserdata(L, text);
			Texture::create(L);
		}
		else
		{
			lua_pushlightuserdata(L, surf);
			Surface::create(L);
		}
		return 1;
	}

	static int create(lua_State* L)
	{
		check(L, { LUA_TSTRING, LUA_TNUMBER });
		cout << "In Font::create" << endl;
		Font* f = (Font*)lua_newuserdata(L, sizeof(Font));
		lua_getfield(L, LUA_REGISTRYINDEX, "__font_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "font"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");
			setfn(L, renderText, "renderText");

			// Set __index of metatable.
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__font_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__font_mt");
		}
		lua_setmetatable(L, -2);
		const char* filename = lua_tostring(L, 1);
		int fontsz = lua_tointeger(L, 2);
		f->font = TTF_OpenFont(filename, fontsz);

		return 1;
	}
};

struct Music
{
	Mix_Music* music;

	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In Music::close" << endl;

		Music* m = (Music*)lua_touserdata(L, 1);
		if (m->music)
		{
			Mix_FreeMusic(m->music);
			m->music = nullptr;
		}
		return 0;
	}

	static int create(lua_State* L)
	{
		check(L, { LUA_TSTRING });
		cout << "In Music::create" << endl;

		Music* m = (Music*)lua_newuserdata(L, sizeof(Music));
		lua_getfield(L, LUA_REGISTRYINDEX, "__music_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "music"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");

			// Set __index of metatable.
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__music_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__music_mt");
		}
		lua_setmetatable(L, -2);

		const char* filename = lua_tostring(L, 1);
		m->music = Mix_LoadMUS(filename);
		cout << "Load music error: " << SDL_GetError() << endl;

		return 1;
	}
};

struct MusicPlayer
{
	static int close(lua_State* L)
	{
		check(L, { LUA_TUSERDATA });
		cout << "In MusicPlayer::close" << endl;

		return 0;
	}

	static int play(lua_State* L)
	{
		check(L, { LUA_TUSERDATA, LUA_TUSERDATA });
		MusicPlayer* p = (MusicPlayer*)lua_touserdata(L, 1);
		Music* m = (Music*)lua_touserdata(L, 2);
		cout << "Play music ret: " << Mix_PlayMusic(m->music, 1) << " " << SDL_GetError() << endl;
		return 0;
	}

	static int create(lua_State* L)
	{
		cout << "In MusicPlayer::create" << endl;

		MusicPlayer* m = (MusicPlayer*)lua_newuserdata(L, sizeof(MusicPlayer));
		lua_getfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
		if (lua_type(L, -1) == LUA_TNIL)
		{
			lua_pop(L, 1);
			lua_newtable(L);
			// GC
			lua_pushcfunction(L, close);
			lua_setfield(L, -2, "__gc");

			// Fields
			lua_newtable(L);
			lua_pushstring(L, "musicplayer"); lua_setfield(L, -2, "type");
			setfn(L, close, "close");
			setfn(L, play, "play");

			// Set __index of metatable.
			lua_setfield(L, -2, "__index");

			lua_setfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
			lua_getfield(L, LUA_REGISTRYINDEX, "__musicplayer_mt");
		}
		lua_setmetatable(L, -2);

		return 1;
	}
};

struct LibFS
{
	static int listdir(lua_State* L)
	{
		check(L, { LUA_TSTRING });
		vector<FileInfo> vec = ListDir(lua_tostring(L, 1));
		int sz = vec.size();
		lua_newtable(L);
		for (lua_Integer i = 0; i < sz; i++)
		{
			const FileInfo& info = vec[i];
			lua_newtable(L);
			lua_pushstring(L, info.name.c_str());
			lua_setfield(L, -2, "name");
			lua_pushstring(L, info.type ? "dir" : "file");
			lua_setfield(L, -2, "type");
			lua_pushinteger(L, info.size);
			lua_setfield(L, -2, "size");
			lua_seti(L, -2, i + 1);
		}
		return 1;
	}
	static int create(lua_State* L)
	{
		lua_newtable(L);
		setfn(L, listdir, "listdir");

		return 1;
	}
};

#define reg_in_lua(L, cfunc, name) lua_pushcfunction(L, cfunc); lua_setglobal(L, name)

void check_init(lua_State* L, const char* name, int ret, int expected = 0)
{
	if (ret != expected)
	{
		luaL_error(L, "Failed to initialize %s. ret: %d. expected: %d. SDLError: %s", name, ret, expected, SDL_GetError());
	}
}

int InitEngine(lua_State* L)
{
	int ret;
	ret = SDL_Init(SDL_INIT_EVERYTHING);
	check_init(L, "SDL", ret);
	ret = IMG_Init(IMG_INIT_JPG | IMG_INIT_PNG);
	check_init(L, "IMG", ret, IMG_INIT_JPG | IMG_INIT_PNG);
	ret = TTF_Init();
	check_init(L, "TTF", ret);
	ret = Mix_Init(MIX_INIT_MP3 | MIX_INIT_MOD | MIX_INIT_OGG );
	check_init(L, "MIX", ret, MIX_INIT_MP3 | MIX_INIT_MOD | MIX_INIT_OGG);

	ret = Mix_OpenAudio(44100, MIX_DEFAULT_FORMAT, 2, 512);
	check_init(L, "AUDIO", ret);
	Mix_AllocateChannels(16);

	reg_in_lua(L, Window::create, "Window");
	reg_in_lua(L, Renderer::create, "Renderer");
	reg_in_lua(L, Font::create, "Font");
	reg_in_lua(L, Music::create, "Music");
	reg_in_lua(L, MusicPlayer::create, "MusicPlayer");
	
	LibFS::create(L); lua_setglobal(L, "fs");

	return 0;
}