use ::rltk::RandomNumberGenerator;

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

pub struct DoorPlacement {}

impl MetaMapBuilder for DoorPlacement {
    #[allow(dead_code)]
    fn build_map(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
        self.doors(rng, build_data);
    }
}

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

    fn doors(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
        if let Some(halls_original) = &build_data.corridors {
            let halls = halls_original.clone();
            for hall in halls.iter() {
                // We aren't interested in tiny corridors
                if hall.len() > 2 && self.door_possible(build_data, hall[0]) {
                    build_data.spawn_list.push((hall[0], "Door".to_string()));
                }
            }
        } else {
            // There are no corridors - scan for possible places
            let tiles = build_data.map.tiles.clone();
            for (i, tile) in tiles.iter().enumerate() {
                if *tile == TileType::Floor
                    && self.door_possible(build_data, i)
                    && rng.roll_dice(1, 3) == 1
                {
                    build_data.spawn_list.push((i, "Door".to_string()));
                }
            }
        }
    }

    fn door_possible(&self, build_data: &mut BuilderMap, idx: usize) -> bool {
        // Check that there isn't already something in this tile
        for spawn in build_data.spawn_list.iter() {
            if spawn.0 == idx {
                return false;
            }
        }

        let width = build_data.map.width as usize;
        let height = build_data.map.height as usize;
        let x = idx % width;
        let y = idx / width;

        // Check for east-west door possibility
        if build_data.map.tiles[idx] == TileType::Floor
            && (x > 1 && build_data.map.tiles[idx - 1] == TileType::Floor)
            && (x < width - 2 && build_data.map.tiles[idx + 1] == TileType::Floor)
            && (y > 1 && build_data.map.tiles[idx - width] == TileType::Wall)
            && (y < height - 2 && build_data.map.tiles[idx + width] == TileType::Wall)
        {
            return true;
        }

        // Check for north-south door possibility
        if build_data.map.tiles[idx] == TileType::Floor
            && (x > 1 && build_data.map.tiles[idx - 1] == TileType::Wall)
            && (x < width - 2 && build_data.map.tiles[idx + 1] == TileType::Wall)
            && (y > 1 && build_data.map.tiles[idx - width] == TileType::Floor)
            && (y < height - 2 && build_data.map.tiles[idx + width] == TileType::Floor)
        {
            return true;
        }

        false
    }
}