use crate::components::{Movable, Velocity};
use crate::game::MyGame;

use sdl2::keyboard as sdl;
use specs::RunNow;

pub struct Move<'t> {
    keys: &'t std::collections::HashSet<sdl::Keycode>,
}

impl<'a, 't> specs::System<'a> for Move<'t> {
    type SystemData = (
        specs::ReadStorage<'a, Movable>,
        specs::WriteStorage<'a, Velocity>,
    );

    fn run(&mut self, (movable, mut velocity): Self::SystemData) {
        use specs::Join;

        for (_, vel) in (&movable, &mut velocity).join() {
            vel.dx = 0.0;
            vel.dy = 0.0;

            if self.keys.contains(&sdl::Keycode::W) {
                vel.dy -= 2.0;
            }
            if self.keys.contains(&sdl::Keycode::A) {
                vel.dx -= 2.0;
            }
            if self.keys.contains(&sdl::Keycode::S) {
                vel.dy += 2.0;
            }
            if self.keys.contains(&sdl::Keycode::D) {
                vel.dx += 2.0;
            }
        }
    }
}


pub fn systems(game: &mut MyGame) {
    Move { keys: &game.keys }.run_now(&game.world.res);
}