use super::rect::*;
use rltk::{Algorithm2D, BaseMap, Point, RandomNumberGenerator};
use std::cmp::{max, min};

#[derive(PartialEq, Copy, Clone)]
pub enum TileType {
    Wall,
    Floor,
}
#[derive(Default)]
pub struct Map {
    pub tiles: Vec<TileType>,
    pub rooms: Vec<Rect>,
    pub width: i32,
    pub height: i32,
    pub revealed_tiles: Vec<bool>,
    pub visible_tiles: Vec<bool>,
}

impl Map {
    pub fn xy_idx(&self, x: i32, y: i32) -> usize {
        ((y * self.width) + x) as usize
    }

    pub fn tile_at(&self, x: i32, y: i32) -> TileType {
        self.tiles[self.xy_idx(x, y)]
    }

    fn apply_room_to_map(&mut self, room: &Rect) {
        for x in room.x1..room.x2 {
            for y in room.y1..room.y2 {
                let idx = self.xy_idx(x, y);
                self.tiles[idx] = TileType::Floor
            }
        }
    }

    fn apply_horizontal_tunnel(&mut self, x1: i32, x2: i32, y: i32) {
        for x in min(x1, x2)..=max(x1, x2) {
            let idx = self.xy_idx(x, y);
            self.tiles[idx] = TileType::Floor
        }
    }

    fn apply_vertical_tunnel(&mut self, x: i32, y1: i32, y2: i32) {
        for y in min(y1, y2)..=max(y1, y2) {
            let idx = self.xy_idx(x, y);
            self.tiles[idx] = TileType::Floor
        }
    }

    pub fn new_map_rooms_and_corridors() -> Map {
        let mut map = Map {
            tiles: vec![TileType::Wall; 80 * 50],
            rooms: Vec::new(),
            width: 80,
            height: 50,
            revealed_tiles: vec![false; 80 * 50],
            visible_tiles: vec![false; 80 * 50],
        };

        const MAX_ROOMS: i32 = 30;
        const MIN_SIZE: i32 = 6;
        const MAX_SIZE: i32 = 10;

        let mut rng = RandomNumberGenerator::new();

        for _ in 0..MAX_ROOMS {
            let w = rng.range(MIN_SIZE, MAX_SIZE);
            let h = rng.range(MIN_SIZE, MAX_SIZE);
            let x = rng.roll_dice(1, 80 - w - 1) - 1;
            let y = rng.roll_dice(1, 50 - h - 1) - 1;
            let new_room = Rect::new(x, y, w, h);
            let mut ok = true;
            for other_room in map.rooms.iter() {
                if new_room.intersect(other_room) {
                    ok = false
                }
            }
            if ok {
                map.apply_room_to_map(&new_room);
                if map.rooms.len() > 0 {
                    let r1_center = new_room.center();
                    let r2_center = map.rooms[map.rooms.len() - 1].center();
                    if rng.range(0, 2) == 1 {
                        map.apply_horizontal_tunnel(r1_center.0, r2_center.0, r1_center.1);
                        map.apply_vertical_tunnel(r2_center.0, r1_center.1, r2_center.1);
                    } else {
                        map.apply_vertical_tunnel(r1_center.0, r1_center.1, r2_center.1);
                        map.apply_horizontal_tunnel(r1_center.0, r2_center.0, r2_center.1);
                    }
                }
                map.rooms.push(new_room);
            }
        }

        map
    }

    fn is_exit_valid(&self, x: i32, y: i32) -> bool {
        if x < 1 || x > self.width - 1 || y < 1 || y > self.height - 1 {
            return false;
        }
        let idx = self.xy_idx(x, y);
        self.tiles[idx as usize] != TileType::Wall
    }
}

impl BaseMap for Map {
    fn is_opaque(&self, idx: usize) -> bool {
        self.tiles[idx as usize] == TileType::Wall
    }
    
    fn get_available_exits(&self, idx: usize) -> rltk::SmallVec<[(usize, f32); 10]> {
        let mut exits = rltk::SmallVec::new();
        let x = idx as i32 % self.width;
        let y = idx as i32 / self.width;
        let w = self.width as usize;
        // Cardinal directions
        if self.is_exit_valid(x - 1, y) {
            exits.push((idx - 1, 1.0))
        };
        if self.is_exit_valid(x + 1, y) {
            exits.push((idx + 1, 1.0))
        };
        if self.is_exit_valid(x, y - 1) {
            exits.push((idx - w, 1.0))
        };
        if self.is_exit_valid(x, y + 1) {
            exits.push((idx + w, 1.0))
        };
        // Diagonals
        if self.is_exit_valid(x - 1, y - 1) {
            exits.push(((idx - w) - 1, 1.45));
        }
        if self.is_exit_valid(x + 1, y - 1) {
            exits.push(((idx - w) + 1, 1.45));
        }
        if self.is_exit_valid(x - 1, y + 1) {
            exits.push(((idx + w) - 1, 1.45));
        }
        if self.is_exit_valid(x + 1, y + 1) {
            exits.push(((idx + w) + 1, 1.45));
        }
        exits
    }
}

impl Algorithm2D for Map {
    fn dimensions(&self) -> Point {
        Point::new(self.width, self.height)
    }
}