use boll::*;
use common::{Point2D, Rect};
use point; // defined in common, but loaded from main...
use rand::Rng;
use sdl2::event::Event;
use sdl2::event::WindowEvent;
use sdl2::gfx::primitives::DrawRenderer;
use sdl2::keyboard::Keycode;
use sdl2::pixels::Color;
use sdl2::rect::Rect as SDLRect;
use sdl2::render::BlendMode;
use sdl2::render::Canvas;
use sdl2::video::FullscreenType;
use sdl2::video::{SwapInterval, Window};
use sdl2::{EventPump, VideoSubsystem};
use sprites::SpriteManager;
use std::f32::consts::PI;
use time::PreciseTime;

pub type Nanoseconds = u64;

const FPS: u32 = 60;
const NS_PER_FRAME: u32 = 1_000_000_000 / FPS;

#[derive(Default)]
pub struct AppBuilder {
    resolution: Rect<u16>,
    state: Option<Box<dyn AppState>>,
    title: Option<String>,
}

impl AppBuilder {
    pub fn with_resolution(mut self, width: u16, height: u16) -> Self {
        self.resolution = Rect { width, height };
        self
    }

    pub fn with_state(mut self, state: Box<dyn AppState>) -> Self {
        self.state = Some(state);
        self
    }

    pub fn with_title(mut self, title: &str) -> Self {
        self.title = Some(title.to_string());
        self
    }

    pub fn build(self) -> Result<App, String> {
        let context = sdl2::init().unwrap();
        sdl2::image::init(sdl2::image::InitFlag::PNG)?;
        let video = context.video()?;

        self.print_video_display_modes(&video);

        let window = video
            .window(
                &self.title.unwrap(),
                self.resolution.width.into(),
                self.resolution.height.into(),
            )
            .position_centered()
            // .fullscreen()
            // .fullscreen_desktop()
            .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();

        video.gl_set_swap_interval(SwapInterval::VSync)?;

        let event_pump = context.event_pump()?;
        let sprites = SpriteManager::new(canvas.texture_creator());
	let screen = canvas.output_size().unwrap();

        Ok(App {
            canvas,
            event_pump,
            sprites,
            state: self.state.unwrap_or_else(|| Box::new(ActiveState::new(screen))),
        })
    }

    fn print_video_display_modes(&self, video: &VideoSubsystem) {
        println!("video subsystem: {:?}", video);
        println!("current_video_driver: {:?}", video.current_video_driver());
        for display in 0..video.num_video_displays().unwrap() {
            println!(
                "=== display {} - {} ===",
                display,
                video.display_name(display).unwrap()
            );
            println!(
                " display_bounds: {:?}",
                video.display_bounds(display).unwrap()
            );
            println!(
                " num_display_modes: {:?}",
                video.num_display_modes(display).unwrap()
            );
            println!(
                " desktop_display_mode: {:?}",
                video.desktop_display_mode(display).unwrap()
            );
            println!(
                " current_display_mode: {:?}",
                video.current_display_mode(display).unwrap()
            );
            for mode in 0..video.num_display_modes(display).unwrap() {
                println!(
                    "  {:2}: {:?}",
                    mode,
                    video.display_mode(display, mode).unwrap()
                );
            }
        }
        println!("swap interval: {:?}", video.gl_get_swap_interval());
    }
}

pub struct App {
    pub canvas: Canvas<Window>,
    pub event_pump: EventPump,
    pub sprites: SpriteManager,
    pub state: Box<dyn AppState>,
}

impl App {
    #[allow(clippy::new_ret_no_self)]
    pub fn new() -> AppBuilder {
        Default::default()
    }

    pub fn load_sprites(&mut self, sprites: &[(&str, &str)]) {
        for (name, file) in sprites {
            self.sprites.load(name, file);
        }
    }

    pub fn start(&mut self) {
        let mut frame_count: u64 = 0;
        let mut fps_time = PreciseTime::now();
        let mut last_time = PreciseTime::now();
	let screen = self.canvas.output_size().unwrap();
	let screen = Rect::from((screen.0 as i32, screen.1 as i32));

        let mut mario_angle = 0.0;

        'running: loop {
            self.canvas.set_draw_color(Color::RGB(0, 0, 0));
            self.canvas.clear();
            {
                let blocks = 20;
                let size = 32;
                let offset = point!(
                    (screen.width - (blocks + 1) * size) / 2,
                    (screen.height - (blocks + 1) * size) / 2
                );
                let block = self.sprites.get("block");
                for i in 0..blocks {
                    self.canvas
                        .copy(
                            block,
                            None,
                            SDLRect::new((i) * size + offset.x, offset.y, size as u32, size as u32),
                        )
                        .unwrap();
                    self.canvas
                        .copy(
                            block,
                            None,
                            SDLRect::new(
                                (blocks - i) * size + offset.x,
                                (blocks) * size + offset.y,
                                size as u32,
                                size as u32,
                            ),
                        )
                        .unwrap();
                    self.canvas
                        .copy(
                            block,
                            None,
                            SDLRect::new(
                                offset.x,
                                (blocks - i) * size + offset.y,
                                size as u32,
                                size as u32,
                            ),
                        )
                        .unwrap();
                    self.canvas
                        .copy(
                            block,
                            None,
                            SDLRect::new(
                                (blocks) * size + offset.x,
                                (i) * size + offset.y,
                                size as u32,
                                size as u32,
                            ),
                        )
                        .unwrap();
                }
            }
            {
                let size = 64;
                let offset = point!(
                    (screen.width - size) / 2,
                    (screen.height - 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);
                self.canvas
                    .copy_ex(
                        self.sprites.get("mario"),
                        None,
                        SDLRect::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);
                self.canvas
                    .circle(p.x, p.y, 100, Color::RGB(255, 255, 255))
                    .unwrap();
                self.canvas
                    .aa_circle(p.x, p.y, 110, Color::RGB(255, 255, 255))
                    .unwrap();
                self.canvas
                    .ellipse(p.x, p.y, 50, 100, Color::RGB(255, 255, 255))
                    .unwrap();
                self.canvas
                    .aa_ellipse(p.x, p.y, 110, 55, Color::RGB(255, 255, 255))
                    .unwrap();
            }

            //        window.gl_swap_window();
            for event in self.event_pump.poll_iter() {
                match event {
                    Event::Quit { .. }
                    | Event::KeyDown {
                        keycode: Some(Keycode::Escape),
                        ..
                    } => {
                        break 'running;
                    }
                    Event::KeyDown {
                        keycode: Some(Keycode::F11),
                        ..
                    } => {
                        match self.canvas.window().fullscreen_state() {
                            FullscreenType::Off => self
                                .canvas
                                .window_mut()
                                .set_fullscreen(FullscreenType::Desktop),
                            _ => self.canvas.window_mut().set_fullscreen(FullscreenType::Off),
                        }
                        .unwrap();
                    }
                    Event::Window {
                        win_event: WindowEvent::Resized(x, y),
                        ..
                    } => {
                        println!("window resized({}, {})", x, y)
                    }
                    Event::Window {
                        win_event: WindowEvent::Maximized,
                        ..
                    } => {
                        println!("window maximized")
                    }
                    Event::Window {
                        win_event: WindowEvent::Restored,
                        ..
                    } => {
                        println!("window restored")
                    }
                    Event::Window {
                        win_event: WindowEvent::Enter,
                        ..
                    } => {
                        println!("window enter")
                    }
                    Event::Window {
                        win_event: WindowEvent::Leave,
                        ..
                    } => {
                        println!("window leave")
                    }
                    Event::Window {
                        win_event: WindowEvent::FocusGained,
                        ..
                    } => {
                        println!("window focus gained")
                    }
                    Event::Window {
                        win_event: WindowEvent::FocusLost,
                        ..
                    } => {
                        println!("window focus lost")
                    }
                    _ => self.state.on_event(event),
                }
            }

            let duration =
                last_time.to(PreciseTime::now()).num_nanoseconds().unwrap() as Nanoseconds;
            last_time = PreciseTime::now();
            self.state.update(duration);
            self.state.render(&mut self.canvas);
            self.canvas.present();

            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();
            }
        }

        self.state.leave();
    }
}

pub trait AppState {
    fn update(&mut self, dt: Nanoseconds);
    fn render(&self, canvas: &mut Canvas<Window>);
    fn leave(&self);
    fn on_event(&mut self, event: Event);
}

type Bollar = Vec<Box<dyn Boll>>;

pub struct ActiveState {
    screen: Rect<u32>,
    bolls: Bollar,
    boll_size: u32,
}

impl ActiveState {
    pub fn new(screen: (u32, u32)) -> ActiveState {
        ActiveState {
            bolls: Bollar::new(),
            boll_size: 1,
	    screen: Rect::from(screen),
        }
    }

    fn change_boll_count(&mut self, delta: i32) {
        #[allow(clippy::comparison_chain)]
        if delta > 0 {
            for _i in 0..delta {
                self.add_boll();
            }
        } else if delta < 0 {
            for _i in 0..(-delta) {
                self.bolls.pop();
            }
        }
    }

    fn add_boll(&mut self) {
        let mut rng = rand::thread_rng();
        self.bolls.push(Box::new(SquareBoll {
            pos: point!(
                rng.gen_range(0, self.screen.width) as f64,
                rng.gen_range(0, self.screen.height) as f64
            ),
            vel: point!(rng.gen_range(-2.0, 2.0), rng.gen_range(-2.0, 2.0)),
        }));
    }
}

impl AppState for ActiveState {
    fn update(&mut self, dt: Nanoseconds) {
        for b in &mut self.bolls {
            b.update();
        }

        match dt {
            ns if ns < (NS_PER_FRAME - 90_0000) as u64 => self.change_boll_count(100),
            ns if ns > (NS_PER_FRAME + 90_0000) as u64 => self.change_boll_count(-100),
            _ => {}
        }
    }

    fn render(&self, canvas: &mut Canvas<Window>) {
        for b in &self.bolls {
            b.draw(canvas, self.boll_size);
        }
    }

    fn leave(&self) {
        println!("number of bolls: {}", self.bolls.len());
    }

    fn on_event(&mut self, event: Event) {
        match event {
            Event::KeyDown {
                keycode: Some(Keycode::KpPlus),
                ..
            } => self.boll_size = std::cmp::min(self.boll_size + 1, 32),
            Event::KeyDown {
                keycode: Some(Keycode::KpMinus),
                ..
            } => self.boll_size = std::cmp::max(self.boll_size - 1, 1),
            Event::MouseMotion { x, y, .. } => self.bolls.push(Box::new(CircleBoll::new(
                point!(x as f64, y as f64),
                point!(0.0, 0.0),
            ))),
            _ => {}
        }
    }
}