#include "gpu.h"
#include "model_format_utah.h"

#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <string.h>

#define W 800
#define H 600

typedef enum {
	AXIS_X,
	AXIS_Y,
	AXIS_Z,
} axis_t;

static axis_t rot_axis = AXIS_Y;

static void
key_callback(GLFWwindow *window, int key, int scancode, int action, int mods)
{
	(void)window;
	(void)scancode;
	(void)mods;

	if (action != GLFW_PRESS)
		return;

	switch (key) {
	case GLFW_KEY_Q:
		glfwSetWindowShouldClose(window, GL_TRUE);
		break;

	case GLFW_KEY_X:
		rot_axis = AXIS_X;
		break;
	case GLFW_KEY_Y:
		rot_axis = AXIS_Y;
		break;
	case GLFW_KEY_Z:
		rot_axis = AXIS_Z;
		break;
	}
}

int main(int argc, char *argv[])
{
	// Read model from passed path
	if (argc != 2) {
		fprintf(stderr, "Usage: %s PATH/TO/MODEL\n", argv[0]);
		return 1;
	}
	model_t model = model_format_utah_read(argv[1]);

	// Set up window
	glfwInit();
	glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
	glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
	GLFWwindow *window = glfwCreateWindow(W, H, "Foo", nullptr, nullptr);
	assert(window);

	// Register input callbacks
	glfwSetKeyCallback(window, key_callback);

	// Initialise GPU
	const gpu_config_t gpu_config = {
		.application_name = "Foo",
		.window = window,
	};
	gpu_ctx_t gpu;
	gpu_init(&gpu, &gpu_config, model);

	const vec3_t cam = { 0, 4, -4 };
	const vec3_t tgt = { 0, 0.5, 0 };
	mvp_t mvp = {
		.model = MAT4_SCALE(0.667),
		.view = mat4_lookat(cam, tgt, (vec3_t) { 0, 1, 0 }),
		.proj = mat4_perspective((float)W / H, PI / 6, 0.1, 10.0),
	};

	const mat4_t rotx = MAT4_ROTATE_X(PI / 128);
	const mat4_t roty = MAT4_ROTATE_Y(PI / 128);
	const mat4_t rotz = MAT4_ROTATE_Z(PI / 128);

	while (!glfwWindowShouldClose(window)) {
		glfwPollEvents();

		switch (rot_axis) {
		case AXIS_X:
			mvp.model = mat4_mul(rotx, mvp.model);
			break;
		case AXIS_Y:
			mvp.model = mat4_mul(roty, mvp.model);
			break;
		case AXIS_Z:
			mvp.model = mat4_mul(rotz, mvp.model);
			break;
		}

		gpu_render(&gpu, &mvp);
	}

	// Clean up
	gpu_cleanup(&gpu);
	model_cleanup(&model);
	glfwDestroyWindow(window);
	glfwTerminate();

	return 0;
}