#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <lua.h>
#include <lauxlib.h>
#include "util/util.h"

int gl_set_viewport(lua_State *L);
int gl_draw_arrays(lua_State *L);
int gl_draw_elements(lua_State *L);
int gl_set_clear_color(lua_State *L);
int gl_clear(lua_State *L);
int gl_gen_framebuffers(lua_State *L);
int gl_bind_framebuffer(lua_State *L);
int gl_framebuffer_texture_2d(lua_State *L);

void setup_drawing(lua_State *L, int gl_index)
{
	struct honey_tbl_t tbl[] = {
		/* functions */
		H_FUNC("DrawArrays", gl_draw_arrays),
		H_FUNC("DrawElements", gl_draw_elements),
		H_FUNC("ClearColor", gl_set_clear_color),
		H_FUNC("Clear", gl_clear),
		H_FUNC("Viewport", gl_set_viewport),

		/******** enums ********/
		/* rendering primitives */
		H_INT("POINTS", GL_POINTS),
		H_INT("LINES", GL_LINES),
		H_INT("TRIANGLES", GL_TRIANGLES),

		/* clear bitmasks */
		H_INT("COLOR_BUFFER_BIT", GL_COLOR_BUFFER_BIT),
		H_INT("DEPTH_BUFFER_BIT", GL_DEPTH_BUFFER_BIT),
		H_INT("STENCIL_BUFFER_BIT", GL_STENCIL_BUFFER_BIT),

		H_END
	};
	create_table(L, tbl);
	append_table(L, gl_index, lua_gettop(L));
	lua_pop(L, 1);
}

int gl_set_clear_color(lua_State *L)
{
	lua_Number r, g, b, a;
	r = luaL_checknumber(L, 1);
	g = luaL_checknumber(L, 2);
	b = luaL_checknumber(L, 3);
	a = luaL_checknumber(L, 4);
	glClearColor(r, g, b, a);
	return 0;
}


int gl_clear(lua_State *L)
{
	lua_Integer mask = luaL_checkinteger(L, 1);
	glClear(mask);
	return 0;
}


int gl_draw_arrays(lua_State *L)
{
	lua_Integer mode, first, count;
	mode = luaL_checkinteger(L, 1);
	first = luaL_checkinteger(L, 2);
	count = luaL_checkinteger(L, 3);
	glDrawArrays(mode, first, count);
	return 0;
}


int gl_draw_elements(lua_State *L)
{
	lua_Integer mode, count, type, offset;
	mode = luaL_checkinteger(L, 1);
	count = luaL_checkinteger(L, 2);
	type = luaL_checkinteger(L, 3);
	offset = luaL_checkinteger(L, 4);
	glDrawElements(mode, count, type, (const void*)offset);
	return 0;
}


int gl_set_viewport(lua_State *L)
{
	lua_Integer x, y, w, h;
	x = luaL_checkinteger(L, 1);
	y = luaL_checkinteger(L, 2);
	w = luaL_checkinteger(L, 3);
	h = luaL_checkinteger(L, 4);
	glViewport(x, y, w, h);
	return 0;
}


int gl_gen_framebuffers(lua_State *L)
{
	int framebuffer;
	glGenFramebuffers(1, &framebuffer);
	lua_pushinteger(L, framebuffer);
	return 1;
}


int gl_bind_framebuffer(lua_State *L)
{
	int target = luaL_checkinteger(L, 1);
	int framebuffer = luaL_checkinteger(L, 2);
	glBindFramebuffer(target, framebuffer);
	return 0;
}


int gl_framebuffer_texture_2d(lua_State *L)
{
	int target = luaL_checkinteger(L, 1);
	int attachment = luaL_checkinteger(L, 2);
	int textarget = luaL_checkinteger(L, 3);
	int texture = luaL_checkinteger(L, 4);
	int level = luaL_checkinteger(L, 5);

	glFramebufferTexture2D(target, attachment, textarget, texture, level);
	return 0;
}