import asyncio
from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from pathlib import Path
from tempfile import TemporaryDirectory

from watchfiles import awatch, Change


@asynccontextmanager
async def log_file_changes(path) -> AsyncIterator[asyncio.Queue]:
    """
    Async context manager for watching file changes.

    Usage:
        async with filesystem.watch_files():
            # File changes will be automatically detected and processed
            await some_other_work()
    """

    change_queue = asyncio.Queue()

    async def _watch_files() -> None:
        try:
            async for changes in awatch(path):
                for change in changes:
                    change_queue.put_nowait(change)
        except asyncio.CancelledError:
            # Expected when stopping the watcher
            pass

    watch_task = asyncio.create_task(_watch_files())
    try:
        # This gives _watch_files() the chance to run until the point awatch()
        # has set up the necessary inotify watches and suspends itself to wait
        # for events.
        await asyncio.sleep(0)
        yield change_queue
    finally:
        watch_task.cancel()
        try:
            await watch_task
        except asyncio.CancelledError:
            pass


async def test_log_file_changes() -> None:
    with TemporaryDirectory() as tmpdir:
        tmp_path = Path(tmpdir)
        test_file = tmp_path / "test.txt"

        async with log_file_changes(tmp_path) as change_queue:
            test_file.write_text("initial content")
            change = await asyncio.wait_for(change_queue.get(), timeout=1.0)
            assert change[0] == Change.added
            assert change[1] == str(test_file)


if __name__ == "__main__":
    asyncio.run(test_log_file_changes())