#!/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_mount
from posix_parity import temp_dir
from posix_parity import touch


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_file = join(merge_base, "file")
                    native_file = join(native_base, "file")

                    touch(merge_file, b"abc")
                    touch(native_file, b"abc")

                    mfd1 = os.open(merge_file, os.O_RDWR)
                    nfd1 = os.open(native_file, os.O_RDWR)
                    mfd2 = os.dup(mfd1)
                    nfd2 = os.dup(nfd1)

                    try:
                        os.close(mfd1)
                        os.close(nfd1)

                        mw = os.write(mfd2, b"X")
                        nw = os.write(nfd2, b"X")
                        if mw != nw:
                            return fail(f"release dup write mismatch mergerfs={mw} native={nw}")

                        os.lseek(mfd2, 0, os.SEEK_SET)
                        os.lseek(nfd2, 0, os.SEEK_SET)
                        mr = os.read(mfd2, 4)
                        nr = os.read(nfd2, 4)
                        if mr != nr:
                            return fail(f"release dup read mismatch mergerfs={mr!r} native={nr!r}")
                    finally:
                        os.close(mfd2)
                        os.close(nfd2)

                    with open(merge_file, "rb") as mf, open(native_file, "rb") as nf:
                        md = mf.read()
                        nd = nf.read()
                    if md != nd:
                        return fail(f"release final data mismatch mergerfs={md!r} native={nd!r}")

                    mfd = os.open(merge_file, os.O_RDONLY)
                    nfd = os.open(native_file, os.O_RDONLY)
                    os.close(mfd)
                    os.close(nfd)
                    try:
                        os.close(mfd)
                        m_err = 0
                    except OSError as exc:
                        m_err = exc.errno
                    try:
                        os.close(nfd)
                        n_err = 0
                    except OSError as exc:
                        n_err = exc.errno
                    if m_err != n_err:
                        return fail(f"release EBADF mismatch mergerfs_errno={m_err} native_errno={n_err}")

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


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