#!/usr/bin/env python3

import errno
import os
import sys
import tempfile

from posix_parity import cleanup_dir
from posix_parity import fail
from posix_parity import join
from posix_parity import mergerfs_get_option
from posix_parity import mergerfs_set_option
from posix_parity import temp_dir
from posix_parity import touch


def get_errno(func):
    try:
        func()
        return 0
    except OSError as exc:
        return exc.errno


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

    mount = sys.argv[1]
    merge_base = temp_dir(mount)

    try:
        path = join(merge_base, "file")
        xname = "user.mergerfs.cfg.test"
        xval = b"v"

        touch(path, b"x")

        try:
            orig = mergerfs_get_option(mount, "xattr")
        except (PermissionError, FileNotFoundError):
            return 0

        try:
            mergerfs_set_option(mount, "xattr", "passthrough")
            set_err = get_errno(lambda: os.setxattr(path, xname, xval))
            get_err = get_errno(lambda: os.getxattr(path, xname))
            if set_err != 0:
                return fail(f"xattr=passthrough setxattr expected success got errno={set_err}")
            if get_err == errno.ENODATA:
                return fail(f"xattr=passthrough getxattr returned ENODATA (known bug): this masks a parity violation")
            if get_err != 0:
                return fail(f"xattr=passthrough getxattr unexpected errno={get_err}")

            mergerfs_set_option(mount, "xattr", "noattr")
            err = get_errno(lambda: os.getxattr(path, xname))
            if err != errno.ENODATA:
                return fail(f"xattr=noattr getxattr expected ENODATA got errno={err}")
            err = get_errno(lambda: os.setxattr(path, xname, xval))
            if err != errno.ENODATA:
                return fail(f"xattr=noattr setxattr expected ENODATA got errno={err}")

            # xattr=nosys is intentionally not tested here. It disables the
            # xattr API, including the runtime interface this test uses to
            # restore options safely.
        except (PermissionError, FileNotFoundError):
            return 0
        finally:
            try:
                mergerfs_set_option(mount, "xattr", orig)
            except OSError:
                pass

        return 0
    finally:
        cleanup_dir(merge_base)


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