const chokidar = require('chokidar');
const path = require('path');
const contentService = require('./content');
const pluginManager = require('./plugin-manager');
const { loadSiteConfig } = require('../config');

class WatcherService {
  constructor() {
    this.watcher = null;
    this.debounceTimer = null;
  }

  start(contentDir, app) {
    console.log(`[Watcher] Starting filesystem watcher on ${contentDir}`);

    this.watcher = chokidar.watch(contentDir, {
      ignored: [
        /(^|[\/\\])\../,              // dotfiles
        /(^|[\/\\])data([\/\\]|$)/,   // ignore entire data/ directory (site.db, journals, etc.)
        /\.db(-journal|-wal|-shm)?$/, // sqlite database files
        /node_modules/
      ],
      persistent: true,
      ignoreInitial: true,
      awaitWriteFinish: {
        stabilityThreshold: 300,
        pollInterval: 100
      }
    });

    const triggerReload = (event, filePath) => {
      const relative = path.relative(contentDir, filePath);
      console.log(`[Watcher] Detected ${event} on ${relative}`);

      clearTimeout(this.debounceTimer);
      this.debounceTimer = setTimeout(() => {
        try {
          const freshConfig = loadSiteConfig();
          pluginManager.loadPlugins(contentDir, app, freshConfig);
          contentService.reload();
          console.log(`[Watcher] Hot reload finished successfully.`);
        } catch (err) {
          console.error(`[Watcher] Error during hot reload:`, err);
        }
      }, 250);
    };

    this.watcher.on('add', (p) => triggerReload('add', p));
    this.watcher.on('change', (p) => triggerReload('change', p));
    this.watcher.on('unlink', (p) => triggerReload('unlink', p));
  }

  close() {
    if (this.watcher) {
      this.watcher.close();
    }
  }
}

module.exports = new WatcherService();