watcher.py

from __future__ import annotations

import time
from pathlib import Path

from watchdog.events import FileSystemEvent, FileSystemEventHandler
from watchdog.observers import Observer


class FolderEventHandler(FileSystemEventHandler):
    def __init__(self, processor, logger, dry_run: bool = False) -> None:
        self.processor = processor
        self.logger = logger
        self.dry_run = dry_run
        self._processed: set[str] = set()

    def on_any_event(self, event: FileSystemEvent) -> None:
        if event.is_directory:
            return

        src = Path(event.src_path)
        dest = Path(event.dest_path) if hasattr(event, "dest_path") and event.dest_path else None
        path = dest if dest and dest.is_file() else src

        if not path.is_file():
            return

        key = str(path.resolve())
        if key in self._processed:
            return
        self._processed.add(key)

        self.logger.info(f"Detected: {path.name}")
        result = self.processor.process(path, dry_run=self.dry_run)
        self.logger.info(f"Result: status={result.status} dst={result.destination}")

        # 処理済みキャッシュは30秒後にクリア（同名ファイルの再投入に対応）
        # シンプルに次のイベントで古いものを掃除
        if len(self._processed) > 100:
            self._processed.clear()


class FolderWatcher:
    def __init__(self, watch_dir: str | Path, processor, logger, dry_run: bool = False) -> None:
        self.watch_dir = Path(watch_dir)
        self.processor = processor
        self.logger = logger
        self.dry_run = dry_run
        self.observer = Observer()

    def start(self) -> None:
        handler = FolderEventHandler(self.processor, self.logger, dry_run=self.dry_run)
        self.observer.schedule(handler, str(self.watch_dir), recursive=False)
        self.observer.start()
        self.logger.info(f"Watching directory: {self.watch_dir.resolve()}")

        try:
            while True:
                time.sleep(1)
        except KeyboardInterrupt:
            self.logger.info("Stopping watcher")
            self.observer.stop()
        self.observer.join()