use core::controller::Controller;
use core::object::boll::Boll;
use core::level::{Level, Wall, IntersectResult::Intersection};
use core::object::{Object, Objects, ObjectState};
use core::render::Renderer;
use geometry::Point;
use point;
use sdl2::rect::Rect;
use sprites::SpriteManager;
use std::cell::RefCell;
use std::rc::Rc;
use time::Duration;

////////// TRIGGER /////////////////////////////////////////////////////////////

trait Trigger {
    fn update(&mut self, body: &Body, ctrl: &Controller, dt: Duration) -> Option<Box<dyn State>>;
}

////////// STATE ///////////////////////////////////////////////////////////////

trait State {
    fn enter(&mut self, _body: &mut Body, _ctrl: &Controller, _objects: &mut Objects) {}
    fn exit(&self) {}
    fn update(&mut self, body: &mut Body, ctrl: &Controller, objects: &mut Objects, lvl: &Level, dt: Duration) -> Option<Box<dyn State>>;
}

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

struct Body {
    pos: Point<f64>,
    vel: Point<f64>,
    standing_on: Option<Wall>,
}

pub struct Character {
    ctrl: Rc<RefCell<Controller>>,
    body: Body,
    triggers: Vec<Box<dyn Trigger>>,
    state: Box<dyn State>,
}

impl Character {
    pub fn new(ctrl: Rc<RefCell<Controller>>) -> Self {
	Character {
	    ctrl,
	    body: Body {
		pos: point!(300.0, 300.0),
		vel: point!(0.0, 0.0),
		standing_on: None,
	    },
	    triggers: vec!(Box::new(JumpTrigger)),
	    state: Box::new(FallState),
	}
    }
}

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

	if let Some(state) = self.state.update(&mut self.body, &ctrl, objects, lvl, dt) {
	    self.state.exit();
	    self.state = state;
	    self.state.enter(&mut self.body, &ctrl, objects);
	}

	match &self.body.standing_on {
	    Some(_wall) => {
	    },
	    None => { // in air
		if let Intersection(wall, pos) = lvl.intersect_walls(self.body.pos - self.body.vel, self.body.pos) {
		    self.body.standing_on = Some(wall);
		    self.body.pos = pos;
		    self.body.vel = point!(0.0, 0.0);

		    self.state.exit();
		    self.state = Box::new(StandState);
		    self.state.enter(&mut self.body, &ctrl, objects);
		}
	    }
	}

	for trigger in &mut self.triggers {
	    if let Some(state) = trigger.update(&self.body, &ctrl, dt) {
		self.state.exit();
		self.state = state;
		self.state.enter(&mut self.body, &ctrl, objects);
	    }
	}

	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::new(
		    self.body.pos + point!(0.0, -16.0), // half the height of mario
		    direction * (10.0 + rand::random::<f64>()) + point!(normal.sample(&mut rand::thread_rng()), normal.sample(&mut rand::thread_rng())) + self.body.vel,
		    2,
		)));
	    }
	    ctrl.rumble(1.0, dt);
	    self.body.vel -= direction * 0.1;
	}

	ObjectState::Alive
    }

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

	let ctrl = &self.ctrl.borrow();
	let l = 300.0;
	let pos = (self.body.pos.x as i32, self.body.pos.y as i32);
	// // axis values
	// let p = (self.body.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.body.pos + ctrl.aim.to_point() * l).to_i32().into();
	renderer.draw_line(pos, p, (255, 0, 0));
	draw_cross(renderer, p);
	let p = (self.body.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.body.pos + Point::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();
}

////////// FALLING /////////////////////////////////////////////////////////////

struct FallState;

impl State for FallState {
    fn update(&mut self, body: &mut Body, ctrl: &Controller, _objects: &mut Objects, lvl: &Level, _dt: Duration) -> Option<Box<dyn State>> {
	body.vel += lvl.gravity;
	body.pos += body.vel;

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

	None
    }
}

////////// STANDING ////////////////////////////////////////////////////////////

struct StandState;

impl State for StandState {
    fn update(&mut self, body: &mut Body, _ctrl: &Controller, _objects: &mut Objects, _lvl: &Level, _dt: Duration) -> Option<Box<dyn State>> {
	if let Some(_wall) = &body.standing_on {
	    body.vel *= 0.9;
	}

	None
    }
}

////////// JUMPING /////////////////////////////////////////////////////////////

struct JumpTrigger;

impl Trigger for JumpTrigger {
    fn update(&mut self, body: &Body, ctrl: &Controller, _dt: Duration) -> Option<Box<dyn State>> {
	if body.standing_on.is_some() && ctrl.jump.is_pressed && !ctrl.jump.was_pressed { // this is redundant now because JumpState needs a wall to get starting velocity, but that will probably change
	    Some(Box::new(JumpState))
	} else {
	    None
	}
    }
}

struct JumpState;

impl State for JumpState {
    fn enter(&mut self, body: &mut Body, ctrl: &Controller, _objects: &mut Objects) {
	if let Some(wall) = &body.standing_on {
	    if ctrl.mov.to_point().length() < 0.1 {
		body.vel = wall.normal().into();
	    } else {
		body.vel = ctrl.mov.to_point();
	    }
	    body.vel *= 5.0;
	    body.pos += body.vel * 0.1;
	    body.standing_on = None;
	}
    }

    fn update(&mut self, body: &mut Body, ctrl: &Controller, _objects: &mut Objects, lvl: &Level, _dt: Duration) -> Option<Box<dyn State>> {
	body.vel += lvl.gravity;
	body.pos += body.vel;

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

	None
    }
}