use bevy::prelude::*;

use crate::{
    obstacle::Obstacle,
    player::{Player, move_player},
};

// Hitbox
#[derive(Component)]
pub struct Collider {
    pub size: Vec2,
}

#[derive(Resource, Default)]
pub struct HasCollided(pub bool);

// Check collision with Player
pub fn check_collision_with_player(
    player: Single<(&Transform, &Collider, &mut Sprite), With<Player>>,
    obstacle: Query<(&Transform, &Collider), With<Obstacle>>,
    mut has_collided: ResMut<HasCollided>,
) {
    if has_collided.0 {
        return;
    }

    let (player_transform, player_collider, mut _player_sprite) = player.into_inner();

    // Check whether or not each obstacles overlap the player
    for (collider_transform, collider_collider) in obstacle {
        if overlap(
            player_transform.translation.truncate(),
            player_collider.size / 2.0,
            collider_transform.translation.truncate(),
            collider_collider.size / 2.0,
        ) {
            // player_sprite.color = Color::srgb(1.0, 0.0, 0.0); // Change sprite color
            has_collided.0 = true;
            break;
        }
    }
}

// Test if there is an overlap between 2 boxes
fn overlap(a_center: Vec2, a_half: Vec2, b_center: Vec2, b_half: Vec2) -> bool {
    let overlap_x = (a_center.x - b_center.x).abs() < (a_half.x + b_half.x);
    let overlap_y = (a_center.y - b_center.y).abs() < (a_half.y + b_half.y);
    overlap_x && overlap_y
}

pub struct CollisionPlugin;

impl Plugin for CollisionPlugin {
    fn build(&self, app: &mut App) {
        app.init_resource::<HasCollided>()
            .add_systems(Update, check_collision_with_player.after(move_player));
    }
}