extern crate rand;
extern crate sdl2;
extern crate time;

use std::collections::hash_map::RandomState;
use std::collections::HashMap;
use std::f32::consts::PI;

use rand::Rng;
use sdl2::event::Event;
use sdl2::EventPump;
use sdl2::gfx::primitives::DrawRenderer;
use sdl2::image::LoadTexture;
use sdl2::keyboard::Keycode;
use sdl2::pixels::Color;
use sdl2::rect::Rect;
use sdl2::render::BlendMode;
use sdl2::render::Canvas;
use sdl2::render::Texture;
use sdl2::render::TextureCreator;
use sdl2::video::Window;
use sdl2::video::WindowContext;
use time::PreciseTime;

use boll::Boll;
use common::Point2D;

#[macro_use] mod common;
mod boll;

const SCREEN_WIDTH: u32 = 1280;
const SCREEN_HEIGHT: u32 = (SCREEN_WIDTH as f64 * (1440.0 / 2560.0)) as u32;
const FPS: u32 = 60;
const NS_PER_FRAME: u32 = 1_000_000_000 / FPS;

fn init() -> (Canvas<Window>, EventPump) {
    let context = sdl2::init().unwrap();
    let video = context.video().unwrap();
    let _image_context = sdl2::image::init(sdl2::image::InitFlag::PNG).unwrap();
    let window = video.window("SDL test", SCREEN_WIDTH, SCREEN_HEIGHT)
        .position_centered()
        .opengl()
        .build()
        .unwrap();
    context.mouse().show_cursor(false);
    let mut canvas = window.into_canvas().build().unwrap();
    canvas.set_blend_mode(BlendMode::Add);
    canvas.set_draw_color(Color::RGB(0, 0, 0));
    canvas.clear();
    canvas.present();
    let event_pump = context.event_pump().unwrap();
    (canvas, event_pump)
}

fn load_textures(texture_creator: &TextureCreator<WindowContext>) -> HashMap<&str, Texture, RandomState> {
    let mut textures = HashMap::new();
    textures.insert("block", texture_creator.load_texture("res/block.bmp").unwrap());
    textures.insert("mario", texture_creator.load_texture("res/mario-trans.png").unwrap());
    textures
}

fn main() {
    println!("starting...");
    let (mut canvas, mut event_pump) = init();

    let mut frame_count: u64 = 0;
    let mut fps_time = PreciseTime::now();

    let mut bolls: Vec<Boll> = Vec::new();
    let mut boll_size = 1;

    let texture_creator = canvas.texture_creator();
    let textures = load_textures(&texture_creator);
    let mut mario_angle = 0.0;

    'running: loop {
        let loop_start = PreciseTime::now();
        canvas.set_draw_color(Color::RGB(0, 0, 0));
        canvas.clear();
        {
            let blocks = 20;
            let size = 32;
            let offset = point!((SCREEN_WIDTH as i32 - (blocks + 1) * size) / 2, (SCREEN_HEIGHT as i32 - (blocks + 1) * size) / 2);
            for i in 0..blocks {
                canvas.copy(&(textures.get("block").unwrap()), None, Rect::new((i) * size + offset.x, (0) * size + offset.y, size as u32, size as u32)).unwrap();
                canvas.copy(&(textures.get("block").unwrap()), None, Rect::new((blocks - i) * size + offset.x, (blocks) * size + offset.y, size as u32, size as u32)).unwrap();
                canvas.copy(&(textures.get("block").unwrap()), None, Rect::new((0) * size + offset.x, (blocks - i) * size + offset.y, size as u32, size as u32)).unwrap();
                canvas.copy(&(textures.get("block").unwrap()), None, Rect::new((blocks) * size + offset.x, (i) * size + offset.y, size as u32, size as u32)).unwrap();
            }
        }
        {
            let size = 64;
            let offset = point!((SCREEN_WIDTH as i32 - size) / 2, (SCREEN_HEIGHT as i32 - size) / 2);
            let radius = 110.0 + size as f32 * 0.5;
            let angle = (mario_angle as f32 - 90.0) * PI / 180.0;
            let offset2 = point!((angle.cos() * radius) as i32, (angle.sin() * radius) as i32);
            canvas.copy_ex(&(textures.get("mario").unwrap()), None, Rect::new(offset.x + offset2.x, offset.y + offset2.y, size as u32, size as u32), mario_angle, sdl2::rect::Point::new(size / 2, size / 2), false, false).unwrap();
            mario_angle += 1.0;
            if mario_angle >= 360.0 { mario_angle -= 360.0 }
        }
        {
            let p = point!((SCREEN_WIDTH / 2) as i16, (SCREEN_HEIGHT / 2) as i16);
            canvas.circle(p.x, p.y, 100, Color::RGB(255, 255, 255)).unwrap();
            canvas.aa_circle(p.x, p.y, 110, Color::RGB(255, 255, 255)).unwrap();
            canvas.ellipse(p.x, p.y, 50, 100, Color::RGB(255, 255, 255)).unwrap();
            canvas.aa_ellipse(p.x, p.y, 110, 55, Color::RGB(255, 255, 255)).unwrap();
        }

        for b in &mut bolls {
            b.update();
            b.draw(&mut canvas, boll_size);
        }

//        window.gl_swap_window();
        for event in event_pump.poll_iter() {
            match event {
                Event::Quit { .. } | Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
                    break 'running;
                }
                Event::KeyDown { keycode: Some(Keycode::F11), .. } => {
                    canvas.window_mut()
                        .set_fullscreen(sdl2::video::FullscreenType::True).unwrap();
                }
                Event::KeyDown { keycode: Some(Keycode::KpPlus), .. } => { boll_size = std::cmp::min(boll_size + 1, 32) }
                Event::KeyDown { keycode: Some(Keycode::KpMinus), .. } => { boll_size = std::cmp::max(boll_size - 1, 1) }
                Event::MouseMotion { x, y, .. } => { bolls.push(Boll {
                    pos: point!(x as f64, y as f64),
                    vel: point!(0.0, 0.0),
                }) }
                _ => {}
            }
        }
        canvas.present();

        match loop_start.to(PreciseTime::now()).num_nanoseconds() {
            Some(ns) if ns < (NS_PER_FRAME - 50_0000) as i64 => { change_boll_count(&mut bolls, 100) }
            Some(ns) if ns > (NS_PER_FRAME + 50_0000) as i64 => { change_boll_count(&mut bolls, -100) }
            _ => {}
        }

        frame_count += 1;
        if frame_count == FPS as u64 {
            let duration = fps_time.to(PreciseTime::now()).num_nanoseconds().unwrap() as f64 / 1_000_000_000.0;
            println!("fps: {}", frame_count as f64 / duration);
            frame_count = 0;
            fps_time = PreciseTime::now();
        }
    }

    println!("number of bolls: {}", bolls.len());
}

fn change_boll_count(mut bolls: &mut Vec<Boll>, delta: i32) {
    if delta > 0 {
        for _i in 0..delta {
            add_boll(&mut bolls);
        }
    } else if delta < 0 {
        for _i in 0..delta {
            bolls.pop();
        }
    }
}

fn add_boll(bolls: &mut Vec<Boll>) {
    let mut rng = rand::thread_rng();
    bolls.push(Boll {
        pos: point!(rng.gen_range(0, SCREEN_WIDTH) as f64, rng.gen_range(0, SCREEN_HEIGHT) as f64),
        vel: point!(rng.gen_range(-2.0, 2.0), rng.gen_range(-2.0, 2.0)),
    });
}