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

#define GL_DRAWING_FUNCTIONS \
	X("ClearColor", glClearColor_bind) \
	X("Clear", glClear_bind) \
	X("DrawArrays", glDrawArrays_bind) \
	X("DrawElements", glDrawElements_bind) \
	X("Viewport", glViewport_bind) \
	X("GenFramebuffers", glGenFramebuffers_bind) \
	X("BindFramebuffer", glBindFramebuffer_bind) \
	X("FramebufferTexture2D", glFramebufferTexture2D_bind) \
	X("CullFace", glCullFace_bind) \
	X("BlendFunc", glBlendFunc_bind) \


#define X(name, func) int func(lua_State *L);
GL_DRAWING_FUNCTIONS
#undef X

void setup_drawing(lua_State *L, int gl_index)
{
	struct honey_tbl_t tbl[] = {
		/* functions */
		#define X(name, func) H_FUNC(name, func),
		GL_DRAWING_FUNCTIONS
		#undef X

		/******** 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_INT("FRONT", GL_FRONT),
		H_INT("BACK", GL_BACK),
		H_INT("FRONT_AND_BACK", GL_FRONT_AND_BACK),

		/* BlendFunc factors */
		H_INT("ZERO", GL_ZERO),
		H_INT("ONE", GL_ONE),
		H_INT("SRC_COLOR", GL_SRC_COLOR),
		H_INT("ONE_MINUS_SRC_COLOR", GL_ONE_MINUS_SRC_COLOR),
		H_INT("DST_COLOR", GL_DST_COLOR),
		H_INT("ONE_MINUS_DST_COLOR", GL_ONE_MINUS_DST_COLOR),
		H_INT("SRC_ALPHA", GL_SRC_ALPHA),
		H_INT("ONE_MINUS_SRC_ALPHA", GL_ONE_MINUS_SRC_ALPHA),
		H_INT("DST_ALPHA", GL_DST_ALPHA),
		H_INT("ONE_MINUS_DST_ALPHA", GL_ONE_MINUS_DST_ALPHA), 
		H_INT("CONSTANT_COLOR", GL_CONSTANT_COLOR),
		H_INT("ONE_MINUS_CONSTANT_COLOR", GL_ONE_MINUS_CONSTANT_COLOR),
		H_INT("CONSTANT_ALPHA", GL_CONSTANT_ALPHA),
		H_INT("ONE_MINUS_CONSTANT_ALPHA", GL_ONE_MINUS_CONSTANT_ALPHA),

		H_INT("FRAMEBUFFER", GL_FRAMEBUFFER),

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

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


int glDrawArrays_bind(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 glDrawElements_bind(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 glViewport_bind(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 glGenFramebuffers_bind(lua_State *L)
{
	int framebuffer;
	glGenFramebuffers(1, &framebuffer);
	lua_pushinteger(L, framebuffer);
	return 1;
}


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


int glFramebufferTexture2D_bind(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;
}


int glCullFace_bind(lua_State *L)
{
	int mode = luaL_checkinteger(L, 1);
	glCullFace(mode);
	return 0;
}


int glBlendFunc_bind(lua_State *L)
{
	int sfactor = luaL_checkinteger(L, 1);
	int dfactor = luaL_checkinteger(L, 1);
	glBlendFunc(sfactor, dfactor);
	return 0;
}