/*
    TE4 - T-Engine 4
    Copyright (C) 2009 - 2018 Nicolas Casalini

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Nicolas Casalini "DarkGod"
    darkgod@te4.org
*/

#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
#include "core_lua.h"
#include "tSDL.h"
#include "tgl.h"
#include "types.h"
#include "main.h"
#include "lua_externs.h"

extern SDL_Window *window;
extern SDL_Surface *screen;

static int wait_hooked = 0;
static bool manual_ticks_enabled = FALSE;
static int waiting = 0;
static int waited_count = 0;
static int waited_count_max = 0;
static long waited_ticks = 0;
static int bkg_realw, bkg_realh, bkg_w, bkg_h;
static GLuint bkg_t = 0;
static int wait_draw_ref = LUA_NOREF;

static int draw_last_frame(lua_State *L)
{
	if (!bkg_t) return 0;

	float w = screen->w / screen_zoom;
	float h = screen->h / screen_zoom;

	GLfloat btexcoords[2*4] = {
		0, (float)screen->h/(float)bkg_realh,
		(float)screen->w/(float)bkg_realw, (float)screen->h/(float)bkg_realh,
		(float)screen->w/(float)bkg_realw, 0,
		0, 0
	};
	GLfloat bcolors[4*4] = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
	GLfloat bvertices[2*4] = {
		0, 0,
		w, 0,
		w, h,
		0, h,
	};
	glTexCoordPointer(2, GL_FLOAT, 0, btexcoords);
	glColorPointer(4, GL_FLOAT, 0, bcolors);
	tglBindTexture(GL_TEXTURE_2D, bkg_t);
	glVertexPointer(2, GL_FLOAT, 0, bvertices);
	glDrawArrays(GL_QUADS, 0, 4);
	return 0;
}

bool draw_waiting(lua_State *L)
{
	if (!waiting) return FALSE;

	if (wait_draw_ref != LUA_NOREF)
	{
		lua_rawgeti(L, LUA_REGISTRYINDEX, wait_draw_ref);
		if (lua_isfunction(L, -1)) lua_call(L, 0, 0);
		else lua_pop(L, 1);
	}
	else draw_last_frame(L);

	return TRUE;
}

bool is_waiting()
{
	if (!waiting) return FALSE;
	return TRUE;
}

extern int requested_fps;
static void hook_wait_display(lua_State *L, lua_Debug *ar)
{
	if (!manual_ticks_enabled) waited_count++;
	SDL_PumpEvents();

	static int last_tick = 0;
	int now = SDL_GetTicks();
	if (now - last_tick < (3000 / requested_fps)) return;
	last_tick = now;
	redraw_now(redraw_type_normal);
}

extern long draw_tick_skip;
static int enable(lua_State *L)
{
	waiting++;

	// Grab currently displayed stuff
	if (waiting == 1)
	{
		waited_count = 0;
		waited_count_max = 0;
		manual_ticks_enabled = FALSE;
		waited_ticks = SDL_GetTicks();

		SDL_GL_SwapWindow(window);

		float w = screen->w;
		float h = screen->h;

		bkg_w = w;
		bkg_h = h;

		glGenTextures(1, &bkg_t);
		tglBindTexture(GL_TEXTURE_2D, bkg_t);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

		// In case we can't support NPOT textures round up to nearest POT
		bkg_realw=1;
		bkg_realh=1;
		while (bkg_realw < w) bkg_realw *= 2;
		while (bkg_realh < h) bkg_realh *= 2;
		glTexImage2D(GL_TEXTURE_2D, 0, 3, bkg_realw, bkg_realh, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
		glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 0, 0, w, h);
		printf("Make wait background texture %d : %dx%d (%d, %d)\n", bkg_t, w, h, bkg_realw, bkg_realh);

		int count = 300;
		if (lua_isnumber(L, 1)) count = lua_tonumber(L, 1);
		if (!lua_gethookmask(L))
		{
			lua_sethook(L, hook_wait_display, LUA_MASKCOUNT, count);
			wait_hooked = count;
		}

		if (lua_isfunction(L, 2))
		{
			lua_pushvalue(L, 2);
			lua_call(L, 0, 1);
			wait_draw_ref = luaL_ref(L, LUA_REGISTRYINDEX);
		}

		redraw_now(redraw_type_normal);
	}

	lua_pushboolean(L, waiting == 1);
	lua_pushnumber(L, waiting);
	return 2;
}

static int disable(lua_State *L)
{
	waiting--;
	if (waiting < 0) waiting = 0;
	if (!waiting)
	{
		if (bkg_t)
		{
			glDeleteTextures(1, &bkg_t);
			bkg_t = 0;
		}
		if (wait_hooked) lua_sethook(L, NULL, 0, 0);
		if (wait_draw_ref != LUA_NOREF) luaL_unref(L, LUA_REGISTRYINDEX, wait_draw_ref);
		waited_ticks = SDL_GetTicks() - waited_ticks;
		printf("Wait finished, counted %d, %ld ticks\n", waited_count, waited_ticks);

		waited_count = 0;
		waited_count_max = 0;
	}
	lua_pushboolean(L, waiting > 0);
	lua_pushnumber(L, waiting);
	return 2;
}

static int enable_manual_tick(lua_State *L)
{
	if (!waiting) return 0;
	manual_ticks_enabled = lua_toboolean(L, 1);
	if (!manual_ticks_enabled) lua_sethook(L, hook_wait_display, LUA_MASKCOUNT, wait_hooked);
	else lua_sethook(L, NULL, 0, 0);
	return 0;
}

static int manual_tick(lua_State *L)
{
	if (!waiting) return 0;
	if (manual_ticks_enabled)
	{
		waited_count += lua_tonumber(L, 1);
		hook_wait_display(L, NULL);
	}
	return 0;
}

static int add_max_ticks(lua_State *L)
{
	if (!waiting) return 0;
	waited_count_max += lua_tonumber(L, 1);
	return 0;
}

static int get_ticks(lua_State *L)
{
	lua_pushnumber(L, waited_count);
	lua_pushnumber(L, waited_count_max);
	return 2;
}

static const struct luaL_Reg mainlib[] =
{
	{"drawLastFrame", draw_last_frame},
	{"enable", enable},
	{"disable", disable},
	{"enableManualTick", enable_manual_tick},
	{"manualTick", manual_tick},
	{"addMaxTicks", add_max_ticks},
	{"getTicks", get_ticks},
	{NULL, NULL},
};

int luaopen_wait(lua_State *L)
{
	luaL_openlib(L, "core.wait", mainlib, 0);
	lua_pop(L, 1);
	return 1;
}