use ::rltk::DijkstraMap;
use ::specs::prelude::*;

use crate::components::{EntityMoved, MyTurn, Position, Viewshed, WantsToFlee};
use crate::{spatial, Map};

pub struct FleeAI {}

impl<'a> System<'a> for FleeAI {
    #[allow(clippy::type_complexity)]
    type SystemData = (
        WriteStorage<'a, MyTurn>,
        WriteStorage<'a, WantsToFlee>,
        WriteStorage<'a, Position>,
        WriteExpect<'a, Map>,
        WriteStorage<'a, Viewshed>,
        WriteStorage<'a, EntityMoved>,
        Entities<'a>,
    );

    fn run(&mut self, data: Self::SystemData) {
        let (
            mut turns,
            mut want_flee,
            mut positions,
            mut map,
            mut viewsheds,
            mut entity_moved,
            entities,
        ) = data;

        let mut turn_done: Vec<Entity> = Vec::new();
        for (entity, mut pos, flee, mut viewshed, _myturn) in (
            &entities,
            &mut positions,
            &want_flee,
            &mut viewsheds,
            &turns,
        )
            .join()
        {
            turn_done.push(entity);

            let my_idx = map.xy_idx(pos.x, pos.y);
            map.populate_blocked();

            let flee_map = DijkstraMap::new(map.width, map.height, &flee.indices, &*map, 100.0);
            if let Some(flee_target) = DijkstraMap::find_highest_exit(&flee_map, my_idx, &*map) {
                if !spatial::is_blocked(flee_target) {
                    spatial::move_entity(entity, my_idx, flee_target);
                    viewshed.dirty = true;
                    pos.x = flee_target as i32 % map.width;
                    pos.y = flee_target as i32 / map.width;
                    entity_moved
                        .insert(entity, EntityMoved {})
                        .expect("Unable to insert intent to flee");
                }
            }
        }

        want_flee.clear();

        // Remove turn marker for those that are done
        for done in turn_done.iter() {
            turns.remove(*done);
        }
    }
}