#!/usr/bin/env python3

import os
import sys
import tempfile

from posix_parity import cleanup_dir
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 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")
                    merge_missing = join(merge_base, "missing")
                    native_missing = join(native_base, "missing")
                    merge_dir = join(merge_base, "dir")
                    native_dir = join(native_base, "dir")
                    merge_notdir = join(merge_base, "notdir")
                    native_notdir = join(native_base, "notdir")

                    cleanup_paths([merge_file, merge_notdir])
                    touch(merge_file, b"123456", 0o644)
                    touch(native_file, b"123456", 0o644)
                    os.makedirs(merge_dir, exist_ok=True)
                    os.makedirs(native_dir, exist_ok=True)
                    touch(merge_notdir, b"x", 0o644)
                    touch(native_notdir, b"x", 0o644)

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

                    err = compare_calls("open EISDIR", lambda: os.open(merge_dir, os.O_WRONLY), lambda: os.open(native_dir, os.O_WRONLY))
                    if err:
                        return fail(err)

                    err = compare_calls(
                        "open ENOTDIR",
                        lambda: os.open(join(merge_notdir, "child"), os.O_RDONLY),
                        lambda: os.open(join(native_notdir, "child"), os.O_RDONLY),
                    )
                    if err:
                        return fail(err)

                    mfd = os.open(merge_file, os.O_RDWR)
                    nfd = os.open(native_file, os.O_RDWR)
                    try:
                        os.lseek(mfd, 0, os.SEEK_SET)
                        os.lseek(nfd, 0, os.SEEK_SET)
                        m_data = os.read(mfd, 6)
                        n_data = os.read(nfd, 6)
                        if m_data != n_data:
                            return fail(f"read parity mismatch mergerfs={m_data!r} native={n_data!r}")

                        os.lseek(mfd, 0, os.SEEK_SET)
                        os.lseek(nfd, 0, os.SEEK_SET)
                        mw = os.write(mfd, b"abc")
                        nw = os.write(nfd, b"abc")
                        if mw != nw:
                            return fail(f"write count mismatch mergerfs={mw} native={nw}")
                    finally:
                        os.close(mfd)
                        os.close(nfd)

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


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