#!/usr/bin/env -S uv run --script
# /// script
# dependencies = ["pytest", "watchdog"]
# ///

from pathlib import Path
import stat
import sys
from types import SimpleNamespace
from unittest.mock import Mock, call, patch

import pytest

import monitor_dir as script


@pytest.mark.parametrize("recursive", [False, True])
def test_recursive_scan_does_not_follow_symlinks(tmp_path: Path, recursive: bool) -> None:
    child = tmp_path / "child"
    child.mkdir()
    file_path = child / "file.txt"
    file_path.touch()
    link = tmp_path / "loop"
    link.symlink_to(target=tmp_path, target_is_directory=True)

    expected = {child: True, link: False}
    if recursive:
        expected[file_path] = False
    assert script.take_snapshot(base_dir=tmp_path, recursive=recursive) == expected


def test_changing_inode_numbers_do_not_emit_events(tmp_path: Path) -> None:
    file_path = tmp_path / "file.txt"
    file_path.touch()
    handler = Mock()
    with patch.object(
        target=Path, attribute="lstat",
        side_effect=[
            SimpleNamespace(st_mode=stat.S_IFREG, st_ino=1),
            SimpleNamespace(st_mode=stat.S_IFREG, st_ino=999),
        ],
    ):
        previous = script.take_snapshot(base_dir=tmp_path, recursive=False)
        current = script.take_snapshot(base_dir=tmp_path, recursive=False)

    script.dispatch_changes(previous=previous, current=current, event_handler=handler)
    handler._process_event_type.assert_not_called()


def test_rename_emits_deleted_and_created() -> None:
    source = Path("/watched/before.txt")
    destination = Path("/watched/after.txt")
    handler = Mock()
    script.dispatch_changes(previous={source: False}, current={destination: False}, event_handler=handler)
    assert handler._process_event_type.call_args_list == [
        call(event_name="deleted", path_to_filter_on=source, src_path=source),
        call(event_name="created", path_to_filter_on=destination, src_path=destination),
    ]


def test_failed_scan_preserves_last_snapshot() -> None:
    base_dir = Path("/watched")
    existing = base_dir / "existing.txt"
    created = base_dir / "created.txt"
    handler = Mock()
    with patch.object(
        target=script, attribute="take_snapshot",
        side_effect=[{existing: False}, OSError("SSHFS disconnected"), {existing: False, created: False}],
    ), patch.object(
        target=script.time, attribute="sleep", side_effect=[None, None, KeyboardInterrupt],
    ):
        with pytest.raises(KeyboardInterrupt):
            script.monitor_paths(base_dir=base_dir, recursive=True, interval=1, event_handler=handler)
    handler._process_event_type.assert_called_once_with(
        event_name="created", path_to_filter_on=created, src_path=created,
    )


def test_partial_scan_is_discarded(tmp_path: Path) -> None:
    (tmp_path / "first.txt").touch()
    (tmp_path / "second.txt").touch()
    with patch.object(
        target=Path, attribute="lstat",
        side_effect=[SimpleNamespace(st_mode=stat.S_IFREG), PermissionError("scan interrupted")],
    ):
        with pytest.raises(PermissionError):
            script.take_snapshot(base_dir=tmp_path, recursive=True)


if __name__ == "__main__":
    sys.exit(pytest.main(args=[str(Path(__file__).resolve()), *sys.argv[1:]]))