/// 将 PipeWire SPA 视频格式转换为 DRM FourCC 格式
///
/// PipeWire 使用自己的 VideoFormat 枚举，而 DRM/KMS 使用 FourCC 格式标识。
/// 此函数建立了两者之间的映射关系。
///
/// 支持的格式:
/// 不支持的格式返回 0
/// DRM 格式名描述像素值位布局（大端序），而非内存字节序。
/// 例如 DRM_FORMAT_ARGB8888 在小端 x86 上内存为 [B,G,R,A] = PipeWire BGRA。
pub(super) fn spa_to_drm_fourcc(format: libspa::param::video::VideoFormat) -> u32 {
    use drm_fourcc::DrmFourcc;
    use libspa::param::video::VideoFormat;
    match format {
        VideoFormat::BGRA => DrmFourcc::Argb8888 as u32,
        VideoFormat::BGRx => DrmFourcc::Xrgb8888 as u32,
        VideoFormat::RGBA => DrmFourcc::Abgr8888 as u32,
        VideoFormat::RGBx => DrmFourcc::Xbgr8888 as u32,
        VideoFormat::ARGB => DrmFourcc::Bgra8888 as u32,
        VideoFormat::xRGB => DrmFourcc::Bgrx8888 as u32,
        VideoFormat::ABGR => DrmFourcc::Rgba8888 as u32,
        VideoFormat::xBGR => DrmFourcc::Rgbx8888 as u32,
        _ => 0,
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use drm_fourcc::DrmFourcc;

    #[test]
    fn spa_to_drm_fourcc_all_32bit() {
        use libspa::param::video::VideoFormat;
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::BGRA),
            DrmFourcc::Argb8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::BGRx),
            DrmFourcc::Xrgb8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::RGBA),
            DrmFourcc::Abgr8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::RGBx),
            DrmFourcc::Xbgr8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::ARGB),
            DrmFourcc::Bgra8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::xRGB),
            DrmFourcc::Bgrx8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::ABGR),
            DrmFourcc::Rgba8888 as u32
        );
        assert_eq!(
            spa_to_drm_fourcc(VideoFormat::xBGR),
            DrmFourcc::Rgbx8888 as u32
        );
    }

    #[test]
    fn spa_to_drm_fourcc_unsupported() {
        use libspa::param::video::VideoFormat;
        assert_eq!(spa_to_drm_fourcc(VideoFormat::NV12), 0);
    }
}