# Test for VfsLittle using a RAM device, testing error handling

try:
    import uos
    uos.VfsLfs1
    uos.VfsLfs2
except (ImportError, AttributeError):
    print("SKIP")
    raise SystemExit

class RAMBlockDevice:
    ERASE_BLOCK_SIZE = 1024

    def __init__(self, blocks):
        self.data = bytearray(blocks * self.ERASE_BLOCK_SIZE)

    def readblocks(self, block, buf, off):
        addr = block * self.ERASE_BLOCK_SIZE + off
        for i in range(len(buf)):
            buf[i] = self.data[addr + i]

    def writeblocks(self, block, buf, off):
        addr = block * self.ERASE_BLOCK_SIZE + off
        for i in range(len(buf)):
            self.data[addr + i] = buf[i]

    def ioctl(self, op, arg):
        if op == 4: # block count
            return len(self.data) // self.ERASE_BLOCK_SIZE
        if op == 5: # block size
            return self.ERASE_BLOCK_SIZE
        if op == 6: # erase block
            return 0

def test(bdev, vfs_class):
    print('test', vfs_class)

    # mkfs with too-small block device
    try:
        vfs_class.mkfs(RAMBlockDevice(1))
    except OSError:
        print('mkfs OSError')

    # mount with invalid filesystem
    try:
        vfs_class(bdev)
    except OSError:
        print('mount OSError')

    # set up for following tests
    vfs_class.mkfs(bdev)
    vfs = vfs_class(bdev)
    with vfs.open('testfile', 'w') as f:
        f.write('test')
    vfs.mkdir('testdir')

    # ilistdir
    try:
        vfs.ilistdir('noexist')
    except OSError:
        print('ilistdir OSError')

    # remove
    try:
        vfs.remove('noexist')
    except OSError:
        print('remove OSError')

    # rmdir
    try:
        vfs.rmdir('noexist')
    except OSError:
        print('rmdir OSError')

    # rename
    try:
        vfs.rename('noexist', 'somethingelse')
    except OSError:
        print('rename OSError')

    # mkdir
    try:
        vfs.mkdir('testdir')
    except OSError:
        print('mkdir OSError')

    # chdir to nonexistent
    try:
        vfs.chdir('noexist')
    except OSError:
        print('chdir OSError')
    print(vfs.getcwd()) # check still at root

    # chdir to file
    try:
        vfs.chdir('testfile')
    except OSError:
        print('chdir OSError')
    print(vfs.getcwd()) # check still at root

    # stat
    try:
        vfs.stat('noexist')
    except OSError:
        print('stat OSError')

    # error during seek
    with vfs.open('testfile', 'r') as f:
        f.seek(1 << 30) # SEEK_SET
        try:
            f.seek(1 << 30, 1) # SEEK_CUR
        except OSError:
            print('seek OSError')

bdev = RAMBlockDevice(30)
test(bdev, uos.VfsLfs1)
test(bdev, uos.VfsLfs2)