import { EventEmitter } from 'events';
import fs from 'fs';
import path from 'path';
import { AgentConfigManager } from '@src/core/server/agentConfig.js';
import logger, { debugIf } from '@src/logger/logger.js';
interface ConfigLoader {
getConfigFilePath: () => string;
checkFileModified: () => boolean;
isReloadEnabled: () => boolean;
}
export class ConfigWatcher extends EventEmitter {
private configWatcher: fs.FSWatcher | null = null;
private debounceTimer: ReturnType<typeof setTimeout> | null = null;
private configFilePath: string;
private loader: ConfigLoader;
constructor(configFilePath: string, loader: ConfigLoader) {
super();
this.configFilePath = configFilePath;
this.loader = loader;
}
public startWatching(): void {
if (!this.loader.isReloadEnabled()) {
logger.info('Configuration hot-reload is disabled, skipping file watcher setup');
return;
}
if (this.configWatcher) {
logger.warn('File watcher already started, ignoring duplicate call');
return;
}
try {
const configDir = path.dirname(this.configFilePath);
const configFileName = path.basename(this.configFilePath);
// Verify directory exists before watching
if (!fs.existsSync(configDir)) {
throw new Error(`Configuration directory does not exist: ${configDir}`);
}
this.configWatcher = fs.watch(configDir, (eventType: fs.WatchEventType, filename: string | null) => {
debugIf(() => ({
message: 'Directory change detected',
meta: { eventType, filename, configDir, configFileName },
}));
const isConfigFileEvent =
filename === configFileName ||
(filename && filename.startsWith(configFileName)) ||
(eventType === 'rename' && filename && filename.includes(path.parse(configFileName).name));
if (isConfigFileEvent || this.loader.checkFileModified()) {
debugIf(() => ({
message: 'Configuration file change detected, debouncing reload',
meta: { eventType, filename },
}));
this.debouncedReloadConfig();
}
});
logger.info(`Started watching configuration directory: ${configDir} for file: ${configFileName}`);
} catch (error) {
const errorMsg = `Failed to start watching configuration file: ${error instanceof Error ? error.message : String(error)}`;
logger.error(errorMsg);
throw new Error(errorMsg);
}
}
public stopWatching(): void {
this.configWatcher?.close();
this.configWatcher = null;
logger.info('Stopped watching configuration file');
if (this.debounceTimer) {
clearTimeout(this.debounceTimer);
this.debounceTimer = null;
}
}
private debouncedReloadConfig(): void {
if (this.debounceTimer) {
clearTimeout(this.debounceTimer);
}
const agentConfig = AgentConfigManager.getInstance();
const debounceDelayMs = agentConfig.get('configReload').debounceMs;
this.debounceTimer = setTimeout(() => {
logger.info('Debounce period completed, reloading configuration...');
this.emit('reload');
this.debounceTimer = null;
}, debounceDelayMs);
}
}
