use sdl2::controller::{Axis, Button};
use core::controller::ControllerManager;
use std::cell::RefCell;
use std::rc::Rc;
use core::controller::Controller;
use common::Point2D;
use sdl2::rect::Rect;
use common::Nanoseconds;
use sdl2::event::Event;
use sprites::SpriteManager;
use sdl2::render::Canvas;
use sdl2::video::Window;
use AppState;
use point;

////////// GAMESTATE ///////////////////////////////////////////////////////////

#[derive(Default)]
pub struct GameState {
    world: World,
}

impl GameState {
    pub fn new() -> Self {
	GameState {
	    world: World::new(),
	}
    }
}

impl AppState for GameState {
    fn enter(&mut self, ctrl_man: &mut ControllerManager) {
	if let Some(ctrl) = ctrl_man.controllers.get(&0) {
	    self.world.add(Box::new(Character::new(ctrl.clone())));
	}
    }

    fn leave(&mut self) {}

    fn update(&mut self, dt: Nanoseconds) {
	self.world.update(dt);
    }

    fn render(&mut self, canvas: &mut Canvas<Window>, sprites: &mut SpriteManager) {
	self.world.render(canvas, sprites);
    }

    fn handle_event(&mut self, _event: Event) {}
}

////////// WORLD ///////////////////////////////////////////////////////////////

#[derive(Default)]
pub struct World {
    level: Level,
    objects: Vec<Box<dyn Object>>,
}

impl World {
    pub fn new() -> Self {
	World {
	    level: Level {
		gravity: point!(0.0, 0.1),
		ground: 600.0,
	    },
	    ..Default::default()
	}
    }

    pub fn update(&mut self, dt: Nanoseconds) {
	for o in &mut self.objects {
	    o.update(&self.level, dt);
	}
    }

    pub fn render(&mut self, canvas: &mut Canvas<Window>, sprites: &mut SpriteManager) {
	self.level.render(canvas, sprites);
	for o in &mut self.objects {
	    o.render(canvas, sprites);
	}
    }

    pub fn add(&mut self, object: Box<dyn Object>) {
	self.objects.push(object);
    }
}

////////// LEVEL ///////////////////////////////////////////////////////////////

#[derive(Default)]
pub struct Level {
    gravity: Point2D<f64>,
    ground: f64,		// just to have something
}

impl Level {
    pub fn render(&mut self, canvas: &mut Canvas<Window>, _sprites: &mut SpriteManager) {
	let w = canvas.viewport().width() as i32;
	for i in 1..11 {
	    let y = (i * i - 1) as i32 + self.ground as i32;
	    canvas.set_draw_color((255 - i * 20, 255 - i * 20, 0));
	    canvas.draw_line((0, y), (w, y)).unwrap();
	}
    }
}

////////// OBJECT //////////////////////////////////////////////////////////////

pub trait Object {
    fn update(&mut self, lvl: &Level, dt: Nanoseconds);
    fn render(&mut self, canvas: &mut Canvas<Window>, _sprites: &mut SpriteManager);
}

pub trait Physical {}
pub trait Drawable {}

////////// CHARACTER ///////////////////////////////////////////////////////////

pub struct Character {
    ctrl: Rc<RefCell<Controller>>,
    pos: Point2D<f64>,
    vel: Point2D<f64>,
}

impl Character {
    pub fn new(ctrl: Rc<RefCell<Controller>>) -> Self {
	Character {
	    ctrl,
	    pos: point!(100.0, 100.0),
	    vel: point!(0.0, 0.0),
	}
    }
}

impl Object for Character {
    fn update(&mut self, lvl: &Level, _dt: Nanoseconds) {
	self.vel += lvl.gravity;
	self.pos += self.vel;

	let ctrl = &self.ctrl.borrow().ctrl;

	if self.pos.y >= lvl.ground {
	    self.pos.y = lvl.ground;
	    self.vel.y = 0.0;
	    self.vel.x *= 0.9;

	    if ctrl.button(Button::A) {
		self.vel.y = -5.0;
	    }
	}

	match ctrl.axis(Axis::LeftX) as f64 / 32768.0 {
	    v if v < -0.9 => { self.vel.x -= 0.5 }
	    v if v > 0.9 => { self.vel.x += 0.5 }
	    _ => {}
	}
    }

    fn render(&mut self, canvas: &mut Canvas<Window>, sprites: &mut SpriteManager) {
        let block = sprites.get("mario");
	let size = 32;
        canvas.copy(block, None, Rect::new(self.pos.x as i32, self.pos.y as i32 - size as i32, size, size)).unwrap();
    }
}