use ActiveState;
use AppState;
use common::{Point2D, Radians};
use core::app::StateChange;
use core::controller::Controller;
use core::controller::ControllerManager;
use core::level::{Level, LevelGenerator};
use core::render::Renderer;
use point;
use sdl2::event::Event;
use sdl2::joystick::PowerLevel;
use sdl2::keyboard::Keycode;
use sdl2::rect::Rect;
use sprites::SpriteManager;
use std::cell::RefCell;
use std::rc::Rc;
use time::Duration;

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

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

impl GameState {
    pub fn new() -> Self {
	let lvlgen = LevelGenerator::new(0, 5);
	GameState {
	    world: World::new(lvlgen.generate()),
	    lvlgen,
	}
    }
}

impl AppState for GameState {
    fn enter(&mut self, ctrl_man: &ControllerManager) {
	for (_k, v) in ctrl_man.controllers.iter() {
	    self.world.add(Box::new(Character::new(v.clone())));
	}
    }

    fn leave(&mut self) {}

    fn update(&mut self, dt: Duration) -> Option<StateChange> {
	self.world.update(dt);
	None
    }

    fn render(&mut self, renderer: &mut Renderer, sprites: &SpriteManager) {
	self.world.render(renderer, sprites);
    }

    fn handle_event(&mut self, event: Event) -> Option<StateChange> {
	match event {
	    Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
		return Some(StateChange::Pop)
            }
	    Event::KeyDown { keycode: Some(Keycode::Return), .. } => {
		return Some(StateChange::Push(Box::new(ActiveState::new((800, 600)))))
            }
	    Event::KeyDown { keycode: Some(Keycode::Space), .. } => {
		self.lvlgen.seed = std::time::UNIX_EPOCH.elapsed().unwrap().as_secs() as u32;
		self.world.level = self.lvlgen.generate();
	    }
	    Event::KeyDown { keycode: Some(Keycode::KpPlus), .. } => {
		self.lvlgen.iterations += 1;
		println!("{} iteration(s) of cellular automata", self.lvlgen.iterations);
		self.world.level = self.lvlgen.generate();
	    }
	    Event::KeyDown { keycode: Some(Keycode::KpMinus), .. } => {
		self.lvlgen.iterations = 1.max(self.lvlgen.iterations - 1);
		println!("{} iteration(s) of cellular automata", self.lvlgen.iterations);
		self.world.level = self.lvlgen.generate();
	    }
	    _ => {}
	}
	None
    }
}

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

#[derive(Default)]
pub struct World {
    level: Level,
    objects: Objects,
}

impl World {
    pub fn new(level: Level) -> Self {
	World {
	    level,
	    ..Default::default()
	}
    }

    pub fn update(&mut self, dt: Duration) {
	let mut breeding_ground = vec!();

	for i in (0..self.objects.len()).rev() {
	    if self.objects[i].update(&mut breeding_ground, &self.level, dt) == Dead {
		self.objects.remove(i); // swap_remove is more efficient, but changes the order of the array
	    }
	}

	for o in breeding_ground {
	    self.add(o);
	}

	println!("\x1b[Kobject count: {}\x1b[1A", self.objects.len()); // clear line, print, move cursor up
    }

    pub fn render(&mut self, renderer: &mut Renderer, sprites: &SpriteManager) {
	self.level.render(renderer, sprites);
	for o in &mut self.objects {
	    o.render(renderer, sprites);
	}
    }

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

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

type Objects = Vec<Box<dyn Object>>;

pub trait Object {
    fn update(&mut self, objects: &mut Objects, lvl: &Level, dt: Duration) -> ObjectState;
    fn render(&self, _renderer: &mut Renderer, _sprites: &SpriteManager) {}
}

#[derive(PartialEq)]
pub enum ObjectState { Alive, Dead }
use self::ObjectState::*;


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!(300.0, 300.0),
	    vel: point!(0.0, 0.0),
	}
    }
}

impl Object for Character {
    fn update(&mut self, objects: &mut Objects, lvl: &Level, dt: Duration) -> ObjectState {
	let ctrl = self.ctrl.borrow();

	let x = (self.pos.x / lvl.grid.cell_size as f64).min(lvl.grid.width as f64 - 1.0).max(0.0) as usize;
	let y = (self.pos.y / lvl.grid.cell_size as f64).min(lvl.grid.height as f64 - 1.0).max(0.0) as usize;
	self.vel += lvl.gravity;
	if lvl.grid.cells[x][y] {
	    if self.vel.y > 0.0 && !(ctrl.mov.down() && ctrl.jump.is_pressed) {
		self.vel.y = 0.0;
		self.vel.x *= 0.9;
		self.pos.y -= 1.0;
	    }

	    if !ctrl.mov.down() {
		if ctrl.jump.is_pressed && !ctrl.jump.was_pressed {
		    self.vel.y = -5.0;
		}
	    }
	}
	self.pos += self.vel;

	if ctrl.shoot.is_pressed {
	    use rand::distributions::{Distribution, Normal};
	    let normal = Normal::new(0.0, 0.1);
	    let direction = if ctrl.aim.to_point().length() > 0.1 { ctrl.aim.to_point() } else { ctrl.mov.to_point() };
	    for _i in 0..100 {
		objects.push(Box::new(Boll {
		    pos: self.pos,
		    vel: direction * (10.0 + rand::random::<f64>()) + point!(normal.sample(&mut rand::thread_rng()), normal.sample(&mut rand::thread_rng())) + self.vel,
		    bounces: 2,
		}));
	    }
	    ctrl.rumble(1.0, dt);
	    self.vel -= direction * 0.1;
	}

	if ctrl.start.is_pressed && !ctrl.start.was_pressed {
	    match ctrl.device.power_level() {
		Ok(PowerLevel::Unknown) => { println!("power level unknown"); }
		Ok(PowerLevel::Empty) => { println!("power level empty"); }
		Ok(PowerLevel::Low) => { println!("power level low"); }
		Ok(PowerLevel::Medium) => { println!("power level medium"); }
		Ok(PowerLevel::Full) => { println!("power level full"); }
		Ok(PowerLevel::Wired) => { println!("power level wired"); }
		Err(_) => {}
	    };
	}

	match ctrl.mov.x {
	    v if v < -0.9 && self.vel.x > -5.0 => { self.vel.x -= 0.5 }
	    v if v > 0.9 && self.vel.x < 5.0 => { self.vel.x += 0.5 }
	    _ => {}
	}

	Alive
    }

    fn render(&self, renderer: &mut Renderer, sprites: &SpriteManager) {
        let block = sprites.get("mario");
	let size = 32;
        renderer.blit(block, None, Rect::new(self.pos.x as i32 - size as i32 / 2, self.pos.y as i32 - size as i32, size, size));

	let ctrl = &self.ctrl.borrow();
	let l = 300.0;
	let pos = (self.pos.x as i32, self.pos.y as i32);
	// // axis values
	// let p = (self.pos + ctrl.aim.to_axis_point() * l).to_i32().into();
	// renderer.draw_line(pos, p, (0, 255, 0));
	// draw_cross(renderer, p);
	// values limited to unit vector
	let p = (self.pos + ctrl.aim.to_point() * l).to_i32().into();
	renderer.draw_line(pos, p, (255, 0, 0));
	draw_cross(renderer, p);
	let p = (self.pos + ctrl.mov.to_point() * l).to_i32().into();
	renderer.draw_line(pos, p, (0, 255, 0));
	draw_cross(renderer, p);
	// // circle values
	// let p = (self.pos + Point2D::from(ctrl.aim.a) * l).to_i32().into();
	// renderer.draw_line(pos, p, (0, 0, 255));
	// draw_cross(renderer, p);
    }
}

fn draw_cross(renderer: &mut Renderer, p: (i32, i32)) {
    renderer.canvas().draw_line((p.0 - 5, p.1), (p.0 + 5, p.1)).unwrap();
    renderer.canvas().draw_line((p.0, p.1 - 5), (p.0, p.1 + 5)).unwrap();
}

////////// BOLL ////////////////////////////////////////////////////////////////

pub struct Boll {
    pos: Point2D<f64>,
    vel: Point2D<f64>,
    bounces: u8,
}

impl Object for Boll {
    fn update(&mut self, objects: &mut Objects, lvl: &Level, _dt: Duration) -> ObjectState {
	self.vel += lvl.gravity;
	self.pos += self.vel;

	let x = (self.pos.x / lvl.grid.cell_size as f64).min(lvl.grid.width as f64 - 1.0).max(0.0) as usize;
	let y = (self.pos.y / lvl.grid.cell_size as f64).min(lvl.grid.height as f64 - 1.0).max(0.0) as usize;
	if lvl.grid.cells[x][y] {
	    if self.bounces == 0 {
		return Dead
	    }
	    self.vel *= -0.25;
	    self.pos += self.vel;
	    self.bounces -= 1;
	    use rand::distributions::{Distribution, Normal};
	    let mut rng = rand::thread_rng();
	    let a = Radians(self.vel.to_radians().0 + Normal::new(0.0, 0.75).sample(&mut rng));
	    objects.push(Box::new(Boll {
	    	vel: Point2D::from(a) * Normal::new(1.0, 0.25).sample(&mut rng) * self.vel.length(),
	    	..*self
	    }));
	}

	Alive
    }

    fn render(&self, renderer: &mut Renderer, _sprites: &SpriteManager) {
        let block = _sprites.get("block");
	let size = 4 + self.bounces * 6;
        renderer.blit(block, None, Rect::new(self.pos.x as i32 - size as i32 / 2, self.pos.y as i32 - size as i32 / 2, size as u32, size as u32));
	// renderer.canvas().set_draw_color((0, self.bounces * 100, 255));
	// renderer.canvas().draw_point((self.pos.x as i32, self.pos.y as i32)).unwrap();
    }
}