use crate::render::{

    atlas::{AtlasCollection, SpriteIndex, SpriteLocation},

    camera::Camera,

};

use integral_geometry::{Rect, Size};

use png::{ColorType, Decoder, DecodingError};

use std::{

    collections::HashMap,

    ffi::OsString,

    fs::{read_dir, File},

    io,

    io::BufReader,

    path::{Path, PathBuf},

};

#[derive(PartialEq, Debug, Clone, Copy)]

    Mine = 0,

    Grenade,

    MaxSprite,

}

const SPRITE_LOAD_LIST: &[(SpriteId, &str)] = &[

    (

        SpriteId::Mine,

        "../../share/hedgewars/Data/Graphics/MineOn.png",

    ),

    (

        SpriteId::Grenade,

        "../../share/hedgewars/Data/Graphics/Bomb.png",

    ),

];

const MAX_SPRITES: usize = SpriteId::MaxSprite as usize + 1;

pub struct GearRenderer {

    atlas: AtlasCollection,

    allocation: Box<[SpriteLocation; MAX_SPRITES]>,

}

struct SpriteData {

    size: Size,

    filename: PathBuf,

}

const ATLAS_SIZE: Size = Size::square(2048);

impl GearRenderer {

    pub fn new() -> Self {

        let mut atlas = AtlasCollection::new(ATLAS_SIZE);

        let mut allocation = Box::new([(0, Rect::at_origin(Size::EMPTY)); MAX_SPRITES]);

        for (sprite, file) in SPRITE_LOAD_LIST {

            let path = Path::new(file);

            let size = load_sprite_size(path).expect(&format!("Unable to open {}", file));

            let index = atlas

                .insert_sprite(size)

                .expect(&format!("Could not store sprite {:?}", sprite));

            let (texture_index, rect) = atlas.get_rect(index).unwrap();

            let mut pixels = vec![0; size.area()].into_boxed_slice();

            load_sprite_pixels(path, mapgen::theme::slice_u32_to_u8_mut(&mut pixels[..]))

                .expect("Unable to load Graphics");

            texture.update(

                rect,

                mapgen::theme::slice_u32_to_u8_mut(&mut pixels[..]),

            );

            allocation[*sprite as usize] = (texture_index, rect);

        }

        Self { atlas, allocation }

    }

    pub fn render(&mut self, camera: &Camera) {

        let projection = camera.projection();

    }

}

fn load_sprite_pixels(path: &Path, buffer: &mut [u8]) -> io::Result<Size> {

    let decoder = Decoder::new(BufReader::new(File::open(path)?));

    let (info, mut reader) = decoder.read_info()?;

    let size = Size::new(info.width as usize, info.height as usize);

    reader.next_frame(buffer)?;

    Ok(size)

}

fn load_sprite_size(path: &Path) -> io::Result<Size> {

    let decoder = Decoder::new(BufReader::new(File::open(path)?));

    let (info, mut reader) = decoder.read_info()?;

    let size = Size::new(info.width as usize, info.height as usize);

    Ok(size)

}

fn load_sprites(path: &Path) -> io::Result<Vec<SpriteData>> {

    let mut result = vec![];

    for file in read_dir(path)? {

        let file = file?;

        if let Some(extension) = file.path().extension() {

            if extension == "png" {

                let path = file.path();

                let sprite = load_sprite_size(&path)?;

                result.push(SpriteData {

                    size: sprite,

                    filename: path,

                });

            }

        }

    }

    Ok(result)

}