#!/usr/bin/env python3

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_mount
from posix_parity import mergerfs_set_option
from posix_parity import temp_dir
from posix_parity import touch


def list_and_stat(dirpath):
    out = {}
    for name in os.listdir(dirpath):
        if name in (".", ".."):
            continue
        st = os.lstat(os.path.join(dirpath, name))
        out[name] = (st.st_mode & 0xF000, st.st_size)
    return out


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)

                    merge_dir = join(merge_base, "dir")
                    native_dir = join(native_base, "dir")

                    for i in range(40):
                        touch(join(merge_dir, f"f{i:03d}"), bytes(str(i), "ascii"))
                        touch(join(native_dir, f"f{i:03d}"), bytes(str(i), "ascii"))

                    m_map = list_and_stat(merge_dir)
                    n_map = list_and_stat(native_dir)
                    if m_map != n_map:
                        return fail("readdir+getattr map mismatch between mergerfs and native")

                    try:
                        orig = mergerfs_get_option(mount, "func.readdir")
                    except (PermissionError, FileNotFoundError, OSError):
                        return 0

                    try:
                        for mode in ("seq", "cosr:2:2", "cor:2:2"):
                            mergerfs_set_option(mount, "func.readdir", mode)
                            got = list_and_stat(merge_dir)
                            if got != m_map:
                                return fail(f"func.readdir={mode} changed readdir+getattr semantic output")
                    except (PermissionError, FileNotFoundError, OSError):
                        return 0
                    finally:
                        try:
                            mergerfs_set_option(mount, "func.readdir", orig)
                        except OSError:
                            pass

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


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