use rltk::{RandomNumberGenerator, RGB, Rltk, Algorithm2D, Point, BaseMap};
use super::{Rect};
use std::cmp::{max, min};
use specs::prelude::*;

#[derive(PartialEq, Copy, Clone)]
pub enum TileType {
    Wall, 
    Floor
}

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 as usize * self.width as usize) + x as usize
    }

    fn apply_room_to_map(&mut self, room: &Rect) {
        for y in room.y1 +1 ..= room.y2 {
            for x in room.x1 + 1 ..= room.x2 {
                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);
            if idx > 0 && idx < self.width as usize * self.height as usize {
                self.tiles[idx as usize] = TileType::Floor;
            }
        }
    }

    fn apply_vertical_tunnel(&mut self, y1:i32, y2:i32, x:i32) {
        for y in min(y1,y2) ..= max(y1,y2) {
            let idx = self.xy_idx(x, y);
            if idx > 0 && idx < self.width as usize * self.height as usize {
                self.tiles[idx as usize] = 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, map.width - w - 1) - 1;
            let y = rng.roll_dice(1, map.height - 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.is_empty() {
                    let (new_x, new_y) = new_room.center();
                    let (prev_x, prev_y) = map.rooms[map.rooms.len()-1].center();
                    if rng.range(0,2) == 1 {
                        map.apply_horizontal_tunnel(prev_x, new_x, prev_y);
                        map.apply_vertical_tunnel(prev_y, new_y, new_x);
                    } else {
                        map.apply_vertical_tunnel(prev_y, new_y, prev_x);
                        map.apply_horizontal_tunnel(prev_x, new_x, new_y);
                    }
                }
            
                map.rooms.push(new_room);        
            }
        }
    
        map
    }



}
impl Algorithm2D for Map {
    fn dimensions(&self) -> Point {
        Point::new(self.width, self.height)
    }
}
impl BaseMap for Map {
    fn is_opaque(&self, idx:usize) -> bool {
        self.tiles[idx as usize] == TileType::Wall
    }
}

// /// Makes a map with solid boundaries and 400 randomly placed walls. No guarantees that it won't
// /// look awful.
// pub fn new_map_test() -> Vec<TileType> {
//     let mut map = vec![TileType::Floor; 80*50];

//     // Make the boundaries walls
//     for x in 0..80 {
//         map[xy_idx(x, 0)] = TileType::Wall;
//         map[xy_idx(x, 49)] = TileType::Wall;
//     }
//     for y in 0..50 {
//         map[xy_idx(0, y)] = TileType::Wall;
//         map[xy_idx(79, y)] = TileType::Wall;
//     }

//     // Now we'll randomly splat a bunch of walls. It won't be pretty, but it's a decent illustration.
//     // First, obtain the thread-local RNG:
//     let mut rng = rltk::RandomNumberGenerator::new();

//     for _i in 0..400 {
//         let x = rng.roll_dice(1, 79);
//         let y = rng.roll_dice(1, 49);
//         let idx = xy_idx(x, y);
//         if idx != xy_idx(40, 25) {
//             map[idx] = TileType::Wall;
//         }
//     }

//     return map
// }

pub fn draw_map(ecs: &World, ctx : &mut Rltk) {
    let map = ecs.fetch::<Map>();

    let mut y = 0;
    let mut x = 0;
    for (idx,tile) in map.tiles.iter().enumerate() {
        // Render a tile depending upon the tile type
        if map.revealed_tiles[idx] {
            let glyph;
            let mut fg;
            match tile {
                TileType::Floor => {
                    glyph = rltk::to_cp437('.');
                    fg = RGB::from_f32(0.0, 0.5, 0.5);
                }
                TileType::Wall => {
                    glyph = rltk::to_cp437('#');
                    fg = RGB::from_f32(0., 1.0, 0.);
                }
            }
            if !map.visible_tiles[idx] { fg = fg.to_greyscale() }
            ctx.set(x, y, fg, RGB::from_f32(0., 0., 0.), glyph);
        }

        // Move the coordinates
        x += 1;
        if x > 79 {
            x = 0;
            y += 1;
        }
    }
}