use ::specs::prelude::*;

use crate::components::{Faction, MyTurn, Position, WantsToMelee};
use crate::raws::Reaction;
use crate::Map;

pub struct AdjacentAI {}

impl<'a> System<'a> for AdjacentAI {
    #[allow(clippy::type_complexity)]
    type SystemData = (
        WriteStorage<'a, MyTurn>,
        ReadStorage<'a, Faction>,
        ReadStorage<'a, Position>,
        ReadExpect<'a, Map>,
        WriteStorage<'a, WantsToMelee>,
        Entities<'a>,
        ReadExpect<'a, Entity>,
    );

    fn run(&mut self, data: Self::SystemData) {
        let (mut turns, factions, positions, map, mut want_melee, entities, player) = data;

        let mut turn_done: Vec<Entity> = Vec::new();
        for (entity, _turn, my_faction, pos) in (&entities, &turns, &factions, &positions).join() {
            if entity != *player {
                let mut reactions: Vec<(Entity, Reaction)> = Vec::new();
                let idx = map.xy_idx(pos.x, pos.y);
                let w = map.width;
                let h = map.height;

                // Add possible reactions to adjacents for each direction
                if pos.x > 0 {
                    evaluate(idx - 1, &map, &factions, &my_faction.name, &mut reactions);
                }
                if pos.x < w - 1 {
                    evaluate(idx + 1, &map, &factions, &my_faction.name, &mut reactions);
                }
                if pos.y > 0 {
                    evaluate(
                        idx - w as usize,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }
                if pos.y < h - 1 {
                    evaluate(
                        idx + w as usize,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }
                if pos.y > 0 && pos.x > 0 {
                    evaluate(
                        (idx - w as usize) - 1,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }
                if pos.y > 0 && pos.x < w - 1 {
                    evaluate(
                        (idx - w as usize) + 1,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }
                if pos.y < h - 1 && pos.x > 0 {
                    evaluate(
                        (idx + w as usize) - 1,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }
                if pos.y < h - 1 && pos.x < w - 1 {
                    evaluate(
                        (idx + w as usize) + 1,
                        &map,
                        &factions,
                        &my_faction.name,
                        &mut reactions,
                    );
                }

                let mut done = false;
                for reaction in reactions.iter() {
                    if let Reaction::Attack = reaction.1 {
                        want_melee
                            .insert(entity, WantsToMelee { target: reaction.0 })
                            .expect("Failed to insert intention to attack");
                        done = true;
                    }
                }

                if done {
                    turn_done.push(entity);
                }
            }
        }

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

fn evaluate(
    idx: usize,
    map: &Map,
    factions: &ReadStorage<Faction>,
    my_faction: &str,
    reactions: &mut Vec<(Entity, Reaction)>,
) {
    for other_entity in map.tile_content[idx].iter() {
        if let Some(faction) = factions.get(*other_entity) {
            reactions.push((
                *other_entity,
                crate::raws::faction_reaction(
                    my_faction,
                    &faction.name,
                    &crate::raws::RAWS.lock().unwrap(),
                ),
            ))
        }
    }
}