import { etcdServer } from '../database/etcd.js';
import log4js from 'log4js';
import { loadConfig } from '../config.js';
const config = loadConfig();

// Setup logger
const logger = log4js.getLogger('Lock Manager');
logger.level = config.server.logLevel;

/**
 * LockManager handles distributed locking using Etcd and broadcasts lock events via websockets.
 */
export class LockManager {
  constructor(socketClient) {
    this.socketClient = socketClient;
    this.setupLocksListeners();
  }

  async lockObject(object) {
    // Add a 'lock' event to the 'locks' stream
    logger.debug('Locking object:', object._id);
    try {
      await etcdServer.setKey(`/${object.type}s/${object._id}/lock`, {
        ...object,
        locked: true
      });
      logger.info(`Lock event to id: ${object._id}`);
      return true;
    } catch (err) {
      logger.error(`Error adding lock event to: ${object._id}:`, err);
      throw err;
    }
  }

  async unlockObject(object) {
    // Add an 'unlock' event to the 'locks' stream
    const key = `/${object.type}s/${object._id}/lock`;
    try {
      logger.debug('Checking user can unlock:', object._id);

      const lockEvent = await etcdServer.getKey(key);

      if (lockEvent?.user === object.user) {
        logger.debug('Unlocking object:', object._id);
        await etcdServer.deleteKey(key);
        logger.info(`Unlocked object: ${object._id}`);
        return true;
      }
    } catch (err) {
      logger.error(`Error unlocking object ${object._id}:`, err);
      throw err;
    }
  }

  async getObjectLock(object) {
    // Get the current lock status of an object and broadcast it
    logger.info('Getting lock status for object:', object._id);
    try {
      const lockKey = `/${object.type}s/${object._id}/lock`;
      const lockValue = await etcdServer.getKey(lockKey);

      if (lockValue) {
        // Object is locked
        logger.debug(`Object ${object._id} is locked`);
        return {
          ...lockValue,
          locked: true
        };
      } else {
        // Object is not locked
        logger.debug(`Object ${object._id} is not locked`);
        return {
          _id: object._id,
          locked: false
        };
      }
    } catch (err) {
      logger.error(`Error getting lock status for object ${object._id}:`, err);
      throw err;
    }
  }

  setupLocksListeners() {
    etcdServer.onPrefixPutEvent(
      '/locks',
      this.socketClient.id,
      (key, value) => {
        const id = key.split('/').pop();
        logger.debug('Lock object event:', id);
        this.socketManager.broadcast('notify_lock_update', {
          ...value,
          locked: true
        });
      }
    );
    etcdServer.onPrefixDeleteEvent('/locks', this.socketClient.id, key => {
      const id = key.split('/').pop();
      logger.debug('Unlock object event:', id);
      this.socketManager.broadcast('notify_lock_update', {
        _id: id,
        locked: false
      });
    });
    logger.info('Subscribed to Etcd stream for lock changes.');
  }
}