#[path = "../../../os-vfs-superblock/src/lib.rs"]
mod superblock;

fn reseal(bytes: &mut [u8; superblock::SUPERBLOCK_BYTES]) {
    let checksum = superblock::checksum(bytes);
    bytes[60..64].copy_from_slice(&checksum.to_le_bytes());
}

#[test]
fn os_vfs_superblock_positive() {
    let encoded = superblock::encode_v1(2048, 7).unwrap();
    assert_eq!(&encoded[..4], b"TKFS");
    assert_eq!(superblock::decode(&encoded, 2048), Ok(superblock::Superblock {
        version: 1, total_blocks: 2048, root_inode: 1, generation: 7
    }));
    assert_eq!(superblock::decode(&encoded, 4096).unwrap().total_blocks, 2048);
    assert_eq!(superblock::decode(&encoded, 2047),
        Err(superblock::Error::BadGeometry));
}

#[test]
fn os_vfs_superblock_negative() {
    let valid = superblock::encode_v1(2048, 7).unwrap();
    let mut wrong_version = valid;
    wrong_version[4..6].copy_from_slice(&2u16.to_le_bytes());
    reseal(&mut wrong_version);
    assert_eq!(superblock::decode(&wrong_version, 4096),
        Err(superblock::Error::UnsupportedVersion));
    let mut wrong_features = valid;
    wrong_features[6..8].copy_from_slice(&1u16.to_le_bytes());
    reseal(&mut wrong_features);
    assert_eq!(superblock::decode(&wrong_features, 4096),
        Err(superblock::Error::UnsupportedFeatures));
    let mut wrong_root = valid;
    wrong_root[20..28].copy_from_slice(&2u64.to_le_bytes());
    reseal(&mut wrong_root);
    assert_eq!(superblock::decode(&wrong_root, 4096),
        Err(superblock::Error::BadRoot));
    let mut wrong_reserved = valid;
    wrong_reserved[40] = 1;
    reseal(&mut wrong_reserved);
    assert_eq!(superblock::decode(&wrong_reserved, 4096),
        Err(superblock::Error::BadReserved));
    let mut wrong_checksum = valid;
    wrong_checksum[60] ^= 1;
    assert_eq!(superblock::decode(&wrong_checksum, 4096),
        Err(superblock::Error::BadChecksum));
    let mut wrong_magic = valid;
    wrong_magic[0] ^= 1;
    assert_eq!(superblock::decode(&wrong_magic, 4096),
        Err(superblock::Error::BadMagic));
    assert_eq!(superblock::encode_v1(15, 7),
        Err(superblock::Error::BadGeometry));
    assert_eq!(superblock::encode_v1(2048, 0),
        Err(superblock::Error::BadGeneration));
}