use mochi::*;
use std::cell::RefCell;
use std::rc::Rc;

struct Game {
    init: bool,
    opponent_paddle_x: f64,
    opponent_paddle_y: f64,
    player_paddle_x: f64,
    player_paddle_y: f64,
    ball_x: f64,
    ball_y: f64,
    ball_vel_x: f64,
    ball_vel_y: f64,
}

fn main() {
    init(include_bytes!("pong.gresource"));
    let game = Rc::new(RefCell::new(Game {
        init: false,
        opponent_paddle_x: 0.0,
        opponent_paddle_y: 0.0,
        player_paddle_x: 0.0,
        player_paddle_y: 0.0,
        ball_x: 0.0,
        ball_y: 0.0,
        ball_vel_x: random() * 400.0 - 200.0,
        ball_vel_y: 200.0 * random_sign(),
    }));

    let img_ball = image_from_resource("/pong/ball.png");
    let img_paddle = image_from_resource("/pong/paddle.png");

    run_game(move |window, ctx, pointer, delta_time| {
        let mut g = game.borrow_mut();
        if !g.init {
            g.opponent_paddle_x = window.width / 2.0;
            g.opponent_paddle_y = 50.0;
            g.player_paddle_x = window.width / 2.0;
            g.player_paddle_y = window.height - 50.0;
            g.ball_x = window.width / 2.0;
            g.ball_y = window.height / 2.0;
            g.init = true;
        }

        g.ball_x += g.ball_vel_x * delta_time;
        g.ball_y += g.ball_vel_y * delta_time;
        g.opponent_paddle_x = g.ball_x;
        g.player_paddle_y = window.height - 50.0;

        if g.ball_y < 50.0 + (img_paddle.get_height() / 2 + img_ball.get_height() / 2) as f64
            || ((g.ball_y
                > window.height
                    - 50.0
                    - (img_paddle.get_height() / 2 + img_ball.get_height() / 2) as f64)
                && (g.ball_x > g.player_paddle_x - (img_paddle.get_width() / 2) as f64
                    && g.ball_x < g.player_paddle_x + (img_paddle.get_width() / 2) as f64)
                && g.ball_y < window.height - 50.0)
        {
            g.ball_vel_y *= -1.0;
        }

        if g.ball_x < (img_ball.get_width() / 2) as f64
            || g.ball_x > window.width - (img_ball.get_width() / 2) as f64
        {
            g.ball_vel_x *= -1.0;
        }

        if g.ball_y > window.height {
            g.ball_x = window.width / 2.0;
            g.ball_y = window.height / 2.0;
            g.ball_vel_x = random() * 400.0 - 200.0;
            g.ball_vel_y = 200.0 * random_sign();
        }

        ctx.clear(1.0, 1.0, 1.0);

        if pointer.is_down {
            g.player_paddle_x = pointer.x;
        }

        ctx.draw_image_centered(g.ball_x, g.ball_y, &img_ball);
        ctx.draw_image_centered(g.opponent_paddle_x, g.opponent_paddle_y, &img_paddle);
        ctx.draw_image_centered(g.player_paddle_x, g.player_paddle_y, &img_paddle);
    });
}