#include <SDL2/SDL.h>
#include <glm/glm.hpp>

#include "camera.h"
#include "dumbLog.h"
#include "renderer.h"
#include "entity.h"


typedef void (*frame_callback_fn) (render_state*);

void
doFrameCallback(render_state* rs)
{
}

void
doRenderLoop(render_state* rs, frame_callback_fn callback_fn, Entity* entities, uint entity_count)
{
	// TODO: move frame delay to renderFrame()
	const uint TARGET_FPS = 60;
	const uint FRAME_DELAY = 1000 / TARGET_FPS;
	uint frameStart, frameTime;
	bool running = true;
	SDL_Event e;

	while (running) {
		frameStart = SDL_GetTicks();

		// TODO: add a better structure for input, and provide a callback to use here
		while (SDL_PollEvent(&e)) {
			if ((e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_ESCAPE)
				|| e.type == SDL_QUIT) {
				running = false;
			}
		}

		callback_fn(rs);
		// TODO: entity pointer and entity count should be stored somewhere on the render_state object
		renRenderFrame(rs, entities, entity_count);
		SDL_GL_SwapWindow(rs->handles.window);
		frameTime = SDL_GetTicks() - frameStart;

		if (FRAME_DELAY > frameTime)
			SDL_Delay(FRAME_DELAY - frameTime);
	}
}

int
main()
{
	// TODO: would be nice to be able to pass in viewport_dims, window title here
	render_state* rs = renInit();
	meInitAssimp();

	// TODO: entInit() doesn't allocate memory because we want to do the allocation in
	// 	one big block, but this is really clunky to use
	Entity spaceship;

	// TODO: this should be handled in entInit
	entSetWorldPosition(spaceship, 0, 0, 0);
	spaceship.scale = glm::vec3(20, 20, 20);
	spaceship.rotation = glm::vec4(0, 0, 0, 0);

	// setup camera
	cameraInitPerspective(
		rs->cam,
		glm::vec3(200, -150, 150),
		spaceship.translation,
		glm::vec3(0,0,1)
	);

	// TODO: renderer::setDefaults() allocates 10 lights based on a MACRO in renderer.cpp
	// 	probably need an interface to add more than that
	// add a light
	rs->num_lights = 1;
	rs->lights[0].position = glm::vec3(200, -150, 150);

	if (entInit(spaceship, "../data/spaceship.glb", rs->default_shader))
		doRenderLoop(rs, doFrameCallback, &spaceship, 1);
	else
		LOG(Error) << "Error initializing entity, exiting\n";

	renShutdown(rs);
	meShutdownAssimp();
	return 0;
}