#!/usr/bin/env python3

import os
import sys
import tempfile

from posix_parity import cleanup_paths
from posix_parity import compare_calls
from posix_parity import fail
from posix_parity import join
from posix_parity import touch


def main():
    if len(sys.argv) != 2:
        print("usage: TEST_posix_truncate_ftruncate <mountpoint>", file=sys.stderr)
        return 1

    mount = sys.argv[1]

    with tempfile.TemporaryDirectory() as native:
        merge_file = join(mount, "posix-truncate/file")
        native_file = join(native, "posix-truncate/file")
        merge_missing = join(mount, "posix-truncate/missing")
        native_missing = join(native, "posix-truncate/missing")

        cleanup_paths([merge_file])
        touch(merge_file, b"1234567890")
        touch(native_file, b"1234567890")

        err = compare_calls("truncate shrink", lambda: os.truncate(merge_file, 3), lambda: os.truncate(native_file, 3))
        if err:
            return fail(err)

        err = compare_calls("truncate ENOENT", lambda: os.truncate(merge_missing, 1), lambda: os.truncate(native_missing, 1))
        if err:
            return fail(err)

        mfd = os.open(merge_file, os.O_RDWR)
        nfd = os.open(native_file, os.O_RDWR)
        try:
            err = compare_calls("ftruncate grow", lambda: os.ftruncate(mfd, 16), lambda: os.ftruncate(nfd, 16))
            if err:
                return fail(err)
        finally:
            os.close(mfd)
            os.close(nfd)

        err = compare_calls("ftruncate EBADF", lambda: os.ftruncate(-1, 4), lambda: os.ftruncate(-1, 4))
        if err:
            return fail(err)

        return 0


if __name__ == "__main__":
    raise SystemExit(main())