package watcher

import (
	"context"
	"log/slog"
	"os"
	"path/filepath"

	"git.savin.nyc/alex/go-iar-notificator/bus"
	"github.com/fsnotify/fsnotify"
)

const (
	EventNewMP3 = "new_mp3" // Event name for new MP3 detection
)

func WatchDirectory(ctx context.Context, dirToWatch string, eb *bus.CustomEventBus, logger *slog.Logger) {
	watcher, err := fsnotify.NewWatcher()
	if err != nil {
		logger.Error("Failed to create directory watcher", "error", err)
		return
	}
	defer watcher.Close()

	// Ensure the directory exists
	if err := os.MkdirAll(dirToWatch, os.ModePerm); err != nil {
		logger.Error("Failed to create watched directory", "error", err, "dir", dirToWatch)
		return
	}

	if err := watcher.Add(dirToWatch); err != nil {
		logger.Error("Failed to add watch on directory", "error", err, "dir", dirToWatch)
		return
	}

	logger.Info("Watching directory for MP3 files", "dir", dirToWatch)

	for {
		select {
		case <-ctx.Done():
			logger.Info("Stopping directory watcher")
			return
		case event, ok := <-watcher.Events:
			if !ok {
				return
			}
			// Trigger on file creation or write (e.g., when saved)
			if (event.Op&fsnotify.Create == fsnotify.Create || event.Op&fsnotify.Write == fsnotify.Write) &&
				filepath.Ext(event.Name) == ".mp3" {
				logger.Info("Detected new or saved MP3 file", "path", event.Name)
				eb.Publish(EventNewMP3, event.Name)
			}
		case err, ok := <-watcher.Errors:
			if !ok {
				return
			}
			logger.Error("Directory watcher error", "error", err)
		}
	}
}