#define _POSIX_C_SOURCE 200809l

#include <stdio.h>
#include <unistd.h>
#include <math.h>
#include <SDL2/SDL.h>

#include "api/api.h"
#include "renderer.h"

#define MAX(a,b) ((a)>(b)?(a):(b))

// TODO: configuration here is required
#define FONT_14PT_SIZE_MM 3

SDL_Window *window;

static double get_scale(void)
{
	float dpi, s;
	SDL_GetDisplayDPI(0, NULL, &dpi, NULL);
	s = (1.0/dpi)*25.4; // size of a point
	// as per standard 14 point should be 3mm
	return floor((FONT_14PT_SIZE_MM/(14*s))*10)/10.0;
}

static void get_exe_filename(char *buf, int sz)
{
#ifdef __linux__
	char path[512];
	sprintf(path, "/proc/%d/exe", getpid());
	int len = readlink(path, buf, sz - 1);
	buf[len] = '\0';
#elif defined(_PREFIX)
	strncpy(buf, _PREFIX, sz);
#else
	strncpy(buf, "/usr/local/share/lite/", sz);
#endif
}

static void init_window_icon(void)
{
	// FIXME: include inside function!?
	#include "../icon.inl"
	(void) icon_rgba_len; /* unused */
	SDL_Surface *surf = SDL_CreateRGBSurfaceFrom(
	  icon_rgba, 64, 64,
	  32, 64 * 4,
	  0x000000ff,
	  0x0000ff00,
	  0x00ff0000,
	  0xff000000);
	SDL_SetWindowIcon(window, surf);
	SDL_FreeSurface(surf);
}


int main(int argc, char **argv)
{
	SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTS);
	SDL_EnableScreenSaver();
	SDL_EventState(SDL_DROPFILE, SDL_ENABLE);
	atexit(SDL_Quit);

#ifdef SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR /* Available since 2.0.8 */
	SDL_SetHint(SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR, "0");
#endif
#if SDL_VERSION_ATLEAST(2, 0, 5)
	SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1");
#endif

	SDL_DisplayMode dm;
	SDL_GetCurrentDisplayMode(0, &dm);

	window = SDL_CreateWindow(
	    "", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
	    dm.w * 0.8, dm.h * 0.8,
	    SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_HIDDEN);
	init_window_icon();
	ren_init(window);

	lua_State *L = luaL_newstate();
	luaL_openlibs(L);
	api_load_libs(L);


	lua_newtable(L);
	for (int i = 0; i < argc; i++) {
		lua_pushstring(L, argv[i]);
		lua_rawseti(L, -2, i + 1);
	}
	lua_setglobal(L, "ARGS");

	lua_pushstring(L, "1.11");
	lua_setglobal(L, "VERSION");

	lua_pushstring(L, SDL_GetPlatform());
	lua_setglobal(L, "PLATFORM");

	lua_pushnumber(L, get_scale());
	lua_setglobal(L, "SCALE");

	char exename[2048];
	get_exe_filename(exename, sizeof(exename));
	lua_pushstring(L, exename);
	lua_setglobal(L, "EXEFILE");

	(void) luaL_dostring(L,
	  "local core\n"
	  "xpcall(function()\n"
	  "  SCALE = tonumber(os.getenv(\"LITE_SCALE\")) or SCALE\n"
	  "  USERDIR = os.getenv(\"HOME\") .. '/.config/lite'\n"
	  "  TEMPDIR = os.getenv(\"LITE_CACHE\") or '/tmp'\n"
	  "  PATHSEP = package.config:sub(1, 1)\n"
	  "  EXEDIR = EXEFILE:match(\"^(.+)[/\\\\].*$\")\n"
	  "  package.path = EXEDIR .. '/data/?.lua;' .. package.path\n"
	  "  package.path = EXEDIR .. '/data/?/init.lua;' .. package.path\n"
	  // load user config file
  	  "  package.path = USERDIR .. '/?.lua;' .. package.path\n"
	  "  package.path = USERDIR .. '/?/init.lua;' .. package.path\n"
	  "  core = require('core')\n"
	  "  core.init()\n"
	  "  core.run()\n"
	  "end, function(err)\n"
	  "  print('Error: ' .. tostring(err))\n"
	  "  print(debug.traceback(nil, 2))\n"
	  "  if core and core.on_error then\n"
	  "    pcall(core.on_error, err)\n"
	  "  end\n"
	  "  os.exit(1)\n"
	  "end)");


	lua_close(L);
	SDL_DestroyWindow(window);

	return EXIT_SUCCESS;
}