use bevy::prelude::*;

use crate::{
    animation::transform::AnimatedTransform,
    card::{CardInHand, Hand, InsertCard},
};

#[derive(Component)]
pub struct DraggableCard;

#[derive(Component)]
pub struct DraggedCard;

#[derive(Resource)]
pub struct MousePosition(pub Vec3);

pub fn mouse_position_system(
    mut mouse: ResMut<MousePosition>,
    window: Single<&Window>,
    camera: Single<(&Camera, &GlobalTransform)>,
) {
    if let Some(Ok(mouse_pos)) = window
        .cursor_position()
        .and_then(|viewport_pos| Some(camera.0.viewport_to_world_2d(camera.1, viewport_pos)))
    {
        mouse.0 = Vec3 {
            x: mouse_pos.x,
            y: mouse_pos.y,
            z: 0.,
        }
    }
}

pub fn card_drag_start(
    event: On<Pointer<DragStart>>,
    mut commands: Commands,
    card_query: Query<(), With<DraggableCard>>,
    dragged_option: Option<Single<&DraggedCard>>,
    mut hand: Single<&mut Hand>,
) {
    if dragged_option.is_some() {
        return;
    }
    if let Err(_) = card_query.get(event.entity) {
        return;
    }

    commands
        .entity(event.entity)
        .insert(DraggedCard)
        .remove::<CardInHand>();

    if let Some(pos) = hand.0.iter().position(|ent| *ent == event.entity) {
        hand.0.remove(pos);
    }
}

pub fn card_drag(
    _: On<Pointer<Drag>>,
    mut card_transform: Single<&mut AnimatedTransform, With<DraggedCard>>,
    mouse_pos: Res<MousePosition>,
) {
    card_transform.translation = mouse_pos.0;
}

pub fn card_drag_end(
    _: On<Pointer<DragEnd>>,
    mut commands: Commands,
    dragged: Single<Entity, With<DraggedCard>>,
) {
    commands.trigger(InsertCard(dragged.entity()));
    commands
        .entity(dragged.entity())
        .remove::<DraggedCard>()
        .insert(CardInHand);
}