#include "game.h"
#include "sys.h"
#include "shader.h"
#include "texture.h"
#include "sprite.h"

#include <GL/glew.h>
#include "gl_utils.h"

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

static void init_gl(game_t game)
{
	i32 flags;
	glGetIntegerv(GL_CONTEXT_FLAGS, &flags);
	if (flags & GL_CONTEXT_FLAG_DEBUG_BIT) {
		info("debug context initialized successfully");
		glEnable(GL_DEBUG_OUTPUT);
		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
		glDebugMessageCallback(gl_debug_output, 0);
		glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, 0, GL_TRUE);
	}
	glViewport(0, 0, game.width, game.height);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glClearColor(0.16f, 0.16f, 0.16f, 1.0f);
}

game_t init_game(i32 width, i32 height)
{
	game_t game = {0};
	game.state = game_active;
	game.running = 1;
	game.width = width;
	game.height = height;
	game.input = init_input();
	init_gl(game);
	game.bindir = get_bin_dir();
	char dir[512] = {0};
	snprintf(dir, 512, "%s/%s", game.bindir, "shaders");
	u32 shader = load_shader(dir, "shader.vert", "shader.frag", 0, "shader");
	glUseProgram(shader);
	mat projection = ortho(0.0f, game.width, game.height, 0.0f, -1.0f, 1.0f);
	uniform_mat(shader, "projection", projection);
	glUseProgram(0);
	snprintf(dir, 512, "%s/%s", game.bindir, "textures");
	load_texture(dir, "gentleman.jpg", "gentleman", 0);
	load_texture(dir, "block.png", "block", 0);
	load_texture(dir, "solid.png", "solid", 0);
	load_texture(dir, "paddle.png", "paddle", 1);
	load_texture(dir, "ball.png", "ball", 1);
	game.renderer = init_renderer(shader);
	snprintf(dir, 512, "%s/%s", game.bindir, "levels");
	game.level = load_level(0, "first.txt", game.width, game.height / 2.0f);
	game.player = (object_t)default_object;
	v2 size = get_texture_size("paddle");
	game.player.size = scale_v2(size, 0.4f); 
	game.player.pos = (v2){width / 2.0f - game.player.size.x / 2.0f, height - game.player.size.y};
	game.player.vel = v2a(500.0f);
	game.player.texture = get_texture_id("paddle");
	game.ball.o = (object_t)default_object;
	game.ball.radius = 12.5f;
	game.ball.o.size = v2a(2.0f * game.ball.radius);
	game.ball.o.pos = (v2){game.player.pos.x + game.player.size.x / 2.0f - game.ball.o.size.x / 2.0f, game.player.pos.y - game.ball.o.size.y};
	game.ball.o.vel = (v2){100.0f, -350.0f};
	game.ball.o.texture = get_texture_id("ball");
	game.ball.stuck = 1;
	return game;
}

void process_input(game_t *game)
{
	if (key_first_press(game->input.escape))
		game->running = 0;
}

void update_game(game_t *game, f32 dt)
{
	f32 vel = game->player.vel.x * dt;
	if (game->state == game_active) {
		if (key_is_pressed(game->input.right)) {
			if (game->player.pos.x + game->player.size.x <= game->width) {
				game->player.pos.x += vel;
				if (game->ball.stuck)
					game->ball.o.pos.x += vel;
			}
		}
		if (key_is_pressed(game->input.left)) {
			if (game->player.pos.x >= 0.0f) {
				game->player.pos.x -= vel;
				if (game->ball.stuck)
					game->ball.o.pos.x -= vel;
			}
		}
		if (key_first_press(game->input.space))
			game->ball.stuck = 0;
	}
	move_ball(&game->ball, dt, game->width);
	/* collisions */
	for (i32 i = 0; i < game->level.count; i++) {
		object_t *tile = game->level.tiles + i;
		if (!tile->destroyed && check_collision(game->ball.o, *tile) && (!tile->solid)) {
			tile->destroyed = 1;
		}
	}
}

void render_game(game_t game)
{
	glClear(GL_COLOR_BUFFER_BIT);
	if (game.state == game_active) {
		render_level(game.renderer, game.level);
		render_object(game.renderer, game.player);
		render_object(game.renderer, game.ball.o);
	}
}