use std::collections::HashSet;

use super::{BuilderMap, MetaMapBuilder};
use crate::{Rect, TileType};

pub struct StraightLineCorridors {}

impl MetaMapBuilder for StraightLineCorridors {
    #[allow(dead_code)]
    fn build_map(&mut self, build_data: &mut BuilderMap) {
        self.corridors(build_data);
    }
}

impl StraightLineCorridors {
    #[allow(dead_code)]
    pub fn new() -> Box<StraightLineCorridors> {
        Box::new(StraightLineCorridors {})
    }

    fn corridors(&mut self, build_data: &mut BuilderMap) {
        let rooms: Vec<Rect>;
        if let Some(rooms_builder) = &build_data.rooms {
            rooms = rooms_builder.clone();
        } else {
            panic!("Straight Line Corridors require a builder with room structures.");
        }

        let mut connected: HashSet<usize> = HashSet::new();
        let mut corridors: Vec<Vec<usize>> = Vec::new();
        for (i, room) in rooms.iter().enumerate() {
            let mut room_distance: Vec<(usize, f32)> = Vec::new();
            let room_center = room.center();
            let room_center_pt = rltk::Point::new(room_center.0, room_center.1);

            for (j, other_room) in rooms.iter().enumerate() {
                if i != j && !connected.contains(&j) {
                    let other_center = other_room.center();
                    let other_center_pt = rltk::Point::new(other_center.0, other_center.1);
                    let distance =
                        rltk::DistanceAlg::Pythagoras.distance2d(room_center_pt, other_center_pt);

                    room_distance.push((j, distance));
                }
            }

            if !room_distance.is_empty() {
                room_distance.sort_by(|a, b| a.1.partial_cmp(&b.1).unwrap());
                let dest_center = rooms[room_distance[0].0].center();
                let line = rltk::line2d(
                    rltk::LineAlg::Bresenham,
                    room_center_pt,
                    rltk::Point::new(dest_center.0, dest_center.1),
                );
                let mut corridor = Vec::new();

                for cell in line.iter() {
                    let idx = build_data.map.xy_idx(cell.x, cell.y);
                    if build_data.map.tiles[idx] != TileType::Floor {
                        build_data.map.tiles[idx] = TileType::Floor;
                        corridor.push(idx);
                    }
                }
                corridors.push(corridor);
                connected.insert(i);
                build_data.take_snapshot();
            }
        }

        build_data.corridors = Some(corridors);
    }
}