use integral_geometry::{Rect, Size};

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

use std::{

    collections::HashMap,

    ffi::OsString,

    fs::{read_dir, File},

    io,

    io::BufReader,

};

pub struct GearRenderer {

    atlas: AtlasCollection,

}

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 texture = Texture2D::new(ATLAS_SIZE, gl::RGBA8, gl::LINEAR);

        }

    }

    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)

}