#[path = "../../../os-turkfs-allocation/src/lib.rs"]
mod allocation;

use allocation::{Bitmap, Error, TruncateFile};

fn fixture() -> (TruncateFile, Bitmap) {
    let bitmap = Bitmap::validate(64, 3, 3 | (1 << 10) | (1 << 20) | (1 << 30)).unwrap();
    let mut bytes = [0x5a; 1536];
    bytes[512..1024].fill(0x6b);
    bytes[1024..].fill(0x7c);
    (TruncateFile::new([10, 20, 30], 1025, bytes, &bitmap).unwrap(), bitmap)
}

#[test]
fn os_turkfs_allocation_truncate_positive() {
    let (file, mut bitmap) = fixture();
    let before = bitmap.counts();
    assert_eq!(file.reader().unwrap().byte(1024), Some(0x7c));
    file.truncate(100, &mut bitmap).unwrap();
    assert_eq!((file.length(), file.block_count()), (100, 1));
    assert_eq!(bitmap.allocated_bits(), 3 | (1 << 10));
    assert_eq!(bitmap.counts().free, before.free + 2);
    let reader = file.reader().unwrap();
    assert_eq!(reader.byte(0), Some(0x5a));
    assert_eq!(reader.byte(99), Some(0x5a));
    assert_eq!(reader.byte(100), None);
    assert_eq!(reader.byte(1024), None);
    assert_eq!(reader.byte(usize::MAX), None);
    drop(reader);
    file.truncate(100, &mut bitmap).unwrap();
    file.truncate(0, &mut bitmap).unwrap();
    assert_eq!((file.length(), file.block_count()), (0, 0));
    assert_eq!(bitmap.allocated_bits(), 3);
    assert_eq!(file.reader().unwrap().byte(0), None);
}

#[test]
fn os_turkfs_allocation_truncate_negative() {
    let (file, mut bitmap) = fixture();
    let first = file.reader().unwrap();
    let second = file.reader().unwrap();
    let before = bitmap;
    assert_eq!(file.truncate(100, &mut bitmap), Err(Error::Busy));
    assert_eq!(bitmap, before);
    assert_eq!((file.length(), file.block_count(), file.active_readers()), (1025, 3, 2));
    assert_eq!(first.byte(1024), Some(0x7c));
    drop(first);
    assert_eq!(file.truncate(0, &mut bitmap), Err(Error::Busy));
    assert_eq!(second.byte(1024), Some(0x7c));
    drop(second);
    assert_eq!(file.active_readers(), 0);
    assert_eq!(file.truncate(1537, &mut bitmap), Err(Error::InvalidLength));
    assert_eq!(bitmap, before);
    let mut corrupt = bitmap;
    corrupt.release(30).unwrap();
    let corrupt_before = corrupt;
    assert_eq!(file.truncate(100, &mut corrupt), Err(Error::UnownedFirstBlock));
    assert_eq!(corrupt, corrupt_before);
    assert_eq!(file.length(), 1025);
    file.truncate(100, &mut bitmap).unwrap();
    assert_eq!(bitmap.allocated_bits(), 3 | (1 << 10));
    assert_eq!(file.reader().unwrap().byte(100), None);
}