#!/usr/bin/env python3

import os
import sys
import tempfile

from posix_parity import cleanup_dir
from posix_parity import compare_calls
from posix_parity import fail
from posix_parity import join
from posix_parity import mergerfs_mount
from posix_parity import temp_dir


def statvfs_cmp(lhs, rhs):
    return (
        lhs.f_namemax == rhs.f_namemax
        and lhs.f_bsize == rhs.f_bsize
        and lhs.f_frsize == rhs.f_frsize
        and lhs.f_bsize > 0
        and lhs.f_frsize > 0
    )


def main():
    try:
        with mergerfs_mount() as (mount, _):
            with tempfile.TemporaryDirectory() as native:
                merge_base = temp_dir(mount)
                try:
                    native_base = join(native, os.path.basename(merge_base))
                    os.makedirs(native_base, exist_ok=True)

                    err = compare_calls(
                        "statvfs mount parity",
                        lambda: os.statvfs(mount),
                        lambda: os.statvfs(native),
                        statvfs_cmp,
                    )
                    if err:
                        return fail(err)

                    err = compare_calls(
                        "statvfs ENOENT",
                        lambda: os.statvfs(join(merge_base, "missing")),
                        lambda: os.statvfs(join(native_base, "missing")),
                    )
                    if err:
                        return fail(err)

                    return 0
                finally:
                    cleanup_dir(merge_base)
    except RuntimeError as exc:
        print(str(exc), end="")
        return 77


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