use std::io::Cursor;

/// Transcode arbitrary cover image bytes (PNG, WebP, GIF, BMP, JPEG, ...) to
/// JPEG so the stored `cover.jpg` is always a real JPEG. Returns `None` if the
/// bytes can't be decoded. CPU-bound — call from `spawn_blocking`.
pub fn to_jpeg(bytes: &[u8]) -> Option<Vec<u8>> {
    let img = image::load_from_memory(bytes).ok()?;
    let mut out = Cursor::new(Vec::new());
    image::DynamicImage::ImageRgb8(img.to_rgb8())
        .write_to(&mut out, image::ImageFormat::Jpeg)
        .ok()?;
    Some(out.into_inner())
}