import * as plugins from '../plugins.js';
import type {
  IHomeAssistantInstanceConfig,
  IHomeAssistantEntity,
  IHomeAssistantConfig,
  IHomeAssistantStateChangedEvent,
  IHomeAssistantMessage,
  IHomeAssistantAuthRequired,
  IHomeAssistantAuthOk,
  IHomeAssistantAuthInvalid,
  IHomeAssistantResult,
  IHomeAssistantEvent,
  THomeAssistantProtocolEvents,
  IHomeAssistantLightServiceData,
  IHomeAssistantClimateServiceData,
  IHomeAssistantCoverServiceData,
  IHomeAssistantFanServiceData,
  IHomeAssistantMediaPlayerServiceData,
} from '../interfaces/homeassistant.interfaces.js';

/**
 * Home Assistant WebSocket Protocol Handler
 * Connects to HA via WebSocket, handles authentication, state subscriptions, and service calls
 */
export class HomeAssistantProtocol extends plugins.events.EventEmitter {
  private ws: InstanceType<typeof plugins.WebSocket> | null = null;
  private config: IHomeAssistantInstanceConfig;
  private messageId: number = 1;
  private pendingRequests: Map<number, {
    resolve: (value: unknown) => void;
    reject: (error: Error) => void;
    timeout: ReturnType<typeof setTimeout>;
  }> = new Map();
  private isAuthenticated: boolean = false;
  private haConfig: IHomeAssistantConfig | null = null;
  private reconnectAttempt: number = 0;
  private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
  private stateSubscriptionId: number | null = null;
  private entityStates: Map<string, IHomeAssistantEntity> = new Map();
  private intentionalDisconnect: boolean = false;

  constructor(config: IHomeAssistantInstanceConfig) {
    super();
    this.config = {
      port: 8123,
      secure: false,
      autoReconnect: true,
      reconnectDelay: 5000,
      ...config,
    };
  }

  /**
   * Get the WebSocket URL for this HA instance
   */
  private get wsUrl(): string {
    const protocol = this.config.secure ? 'wss' : 'ws';
    return `${protocol}://${this.config.host}:${this.config.port}/api/websocket`;
  }

  /**
   * Get connection state
   */
  public get isConnected(): boolean {
    return this.ws !== null && this.ws.readyState === plugins.WebSocket.OPEN && this.isAuthenticated;
  }

  /**
   * Get HA config if authenticated
   */
  public get homeAssistantConfig(): IHomeAssistantConfig | null {
    return this.haConfig;
  }

  /**
   * Get all cached entity states
   */
  public get entities(): Map<string, IHomeAssistantEntity> {
    return this.entityStates;
  }

  /**
   * Connect to Home Assistant
   */
  public async connect(): Promise<void> {
    if (this.ws && this.ws.readyState === plugins.WebSocket.OPEN) {
      return;
    }

    this.intentionalDisconnect = false;

    return new Promise((resolve, reject) => {
      try {
        this.ws = new plugins.WebSocket(this.wsUrl);

        const connectionTimeout = setTimeout(() => {
          if (this.ws) {
            this.ws.close();
            this.ws = null;
          }
          reject(new Error(`Connection timeout to ${this.wsUrl}`));
        }, 10000);

        this.ws.on('open', () => {
          // Connection established, waiting for auth_required
        });

        this.ws.on('message', async (data: Buffer | string) => {
          const message = JSON.parse(data.toString()) as IHomeAssistantMessage;

          if (message.type === 'auth_required') {
            // Send authentication
            await this.sendAuth();
          } else if (message.type === 'auth_ok') {
            clearTimeout(connectionTimeout);
            this.isAuthenticated = true;
            this.reconnectAttempt = 0;

            // Get HA config
            try {
              this.haConfig = await this.getConfig();
              this.emit('authenticated', this.haConfig);
            } catch (err) {
              // Non-fatal, continue anyway
            }

            this.emit('connected');
            resolve();
          } else if (message.type === 'auth_invalid') {
            clearTimeout(connectionTimeout);
            const authInvalid = message as IHomeAssistantAuthInvalid;
            this.emit('auth:failed', authInvalid.message);
            reject(new Error(`Authentication failed: ${authInvalid.message}`));
          } else {
            // Handle other messages
            this.handleMessage(message);
          }
        });

        this.ws.on('error', (error: Error) => {
          this.emit('error', error);
        });

        this.ws.on('close', () => {
          this.isAuthenticated = false;
          this.stateSubscriptionId = null;

          // Reject all pending requests
          for (const [id, request] of this.pendingRequests) {
            clearTimeout(request.timeout);
            request.reject(new Error('Connection closed'));
            this.pendingRequests.delete(id);
          }

          this.emit('disconnected');

          // Auto-reconnect if not intentional
          if (this.config.autoReconnect && !this.intentionalDisconnect) {
            this.scheduleReconnect();
          }
        });
      } catch (err) {
        reject(err);
      }
    });
  }

  /**
   * Disconnect from Home Assistant
   */
  public async disconnect(): Promise<void> {
    this.intentionalDisconnect = true;

    if (this.reconnectTimer) {
      clearTimeout(this.reconnectTimer);
      this.reconnectTimer = null;
    }

    if (this.ws) {
      // Clear all pending requests
      for (const [id, request] of this.pendingRequests) {
        clearTimeout(request.timeout);
        request.reject(new Error('Disconnecting'));
        this.pendingRequests.delete(id);
      }

      this.ws.close();
      this.ws = null;
    }

    this.isAuthenticated = false;
    this.stateSubscriptionId = null;
    this.entityStates.clear();
  }

  /**
   * Send authentication message
   */
  private async sendAuth(): Promise<void> {
    if (!this.ws) return;

    const authMessage = {
      type: 'auth',
      access_token: this.config.token,
    };

    this.ws.send(JSON.stringify(authMessage));
  }

  /**
   * Handle incoming messages
   */
  private handleMessage(message: IHomeAssistantMessage): void {
    if (message.type === 'result') {
      const result = message as IHomeAssistantResult;
      const pending = this.pendingRequests.get(result.id);

      if (pending) {
        clearTimeout(pending.timeout);
        this.pendingRequests.delete(result.id);

        if (result.success) {
          pending.resolve(result.result);
        } else {
          pending.reject(new Error(result.error?.message || 'Unknown error'));
        }
      }
    } else if (message.type === 'event') {
      const event = message as IHomeAssistantEvent;

      if (event.event.event_type === 'state_changed') {
        const stateChanged = event.event.data as IHomeAssistantStateChangedEvent;

        // Update cached state
        if (stateChanged.new_state) {
          this.entityStates.set(stateChanged.entity_id, stateChanged.new_state);
        } else {
          this.entityStates.delete(stateChanged.entity_id);
        }

        this.emit('state:changed', stateChanged);
      }
    }
  }

  /**
   * Send a request and wait for response
   */
  private async sendRequest<T>(type: string, data: Record<string, unknown> = {}): Promise<T> {
    if (!this.ws || !this.isAuthenticated) {
      throw new Error('Not connected to Home Assistant');
    }

    const id = this.messageId++;
    const message = { id, type, ...data };

    return new Promise<T>((resolve, reject) => {
      const timeout = setTimeout(() => {
        this.pendingRequests.delete(id);
        reject(new Error(`Request timeout: ${type}`));
      }, 30000);

      this.pendingRequests.set(id, {
        resolve: resolve as (value: unknown) => void,
        reject,
        timeout,
      });

      this.ws!.send(JSON.stringify(message));
    });
  }

  /**
   * Schedule reconnection attempt
   */
  private scheduleReconnect(): void {
    if (this.reconnectTimer) return;

    this.reconnectAttempt++;
    const delay = Math.min(
      this.config.reconnectDelay! * Math.pow(1.5, this.reconnectAttempt - 1),
      60000 // Max 60 seconds
    );

    this.emit('reconnecting', this.reconnectAttempt);

    this.reconnectTimer = setTimeout(async () => {
      this.reconnectTimer = null;

      try {
        await this.connect();

        // Re-subscribe to state changes
        if (this.isConnected) {
          await this.subscribeToStateChanges();
        }
      } catch {
        // connect() will schedule another reconnect on failure
      }
    }, delay);
  }

  // ==========================================================================
  // Public API - State
  // ==========================================================================

  /**
   * Get HA config
   */
  public async getConfig(): Promise<IHomeAssistantConfig> {
    return this.sendRequest<IHomeAssistantConfig>('get_config');
  }

  /**
   * Subscribe to state change events
   */
  public async subscribeToStateChanges(): Promise<number> {
    const result = await this.sendRequest<{ context: { id: string } }>('subscribe_events', {
      event_type: 'state_changed',
    });

    // Get all current states after subscribing
    const states = await this.getStates();
    for (const entity of states) {
      this.entityStates.set(entity.entity_id, entity);
    }
    this.emit('states:loaded', states);

    this.stateSubscriptionId = this.messageId - 1;
    return this.stateSubscriptionId;
  }

  /**
   * Get all entity states
   */
  public async getStates(): Promise<IHomeAssistantEntity[]> {
    return this.sendRequest<IHomeAssistantEntity[]>('get_states');
  }

  /**
   * Get a specific entity state
   */
  public async getState(entityId: string): Promise<IHomeAssistantEntity | null> {
    // First check cache
    const cached = this.entityStates.get(entityId);
    if (cached) return cached;

    // Otherwise fetch all states and find it
    const states = await this.getStates();
    return states.find((s) => s.entity_id === entityId) || null;
  }

  /**
   * Get entities by domain
   */
  public async getEntitiesByDomain(domain: string): Promise<IHomeAssistantEntity[]> {
    const states = await this.getStates();
    return states.filter((s) => s.entity_id.startsWith(`${domain}.`));
  }

  // ==========================================================================
  // Public API - Service Calls
  // ==========================================================================

  /**
   * Call a Home Assistant service
   */
  public async callService(
    domain: string,
    service: string,
    target?: { entity_id?: string | string[]; device_id?: string | string[]; area_id?: string | string[] },
    serviceData?: Record<string, unknown>
  ): Promise<void> {
    await this.sendRequest('call_service', {
      domain,
      service,
      target,
      service_data: serviceData,
    });
  }

  /**
   * Turn on an entity
   */
  public async turnOn(entityId: string, data?: Record<string, unknown>): Promise<void> {
    const domain = entityId.split('.')[0];
    await this.callService(domain, 'turn_on', { entity_id: entityId }, data);
  }

  /**
   * Turn off an entity
   */
  public async turnOff(entityId: string): Promise<void> {
    const domain = entityId.split('.')[0];
    await this.callService(domain, 'turn_off', { entity_id: entityId });
  }

  /**
   * Toggle an entity
   */
  public async toggle(entityId: string): Promise<void> {
    const domain = entityId.split('.')[0];
    await this.callService(domain, 'toggle', { entity_id: entityId });
  }

  // ==========================================================================
  // Light Services
  // ==========================================================================

  /**
   * Control a light
   */
  public async lightTurnOn(entityId: string, options?: IHomeAssistantLightServiceData): Promise<void> {
    await this.callService('light', 'turn_on', { entity_id: entityId }, options);
  }

  public async lightTurnOff(entityId: string, options?: { transition?: number }): Promise<void> {
    await this.callService('light', 'turn_off', { entity_id: entityId }, options);
  }

  public async lightToggle(entityId: string, options?: IHomeAssistantLightServiceData): Promise<void> {
    await this.callService('light', 'toggle', { entity_id: entityId }, options);
  }

  // ==========================================================================
  // Climate Services
  // ==========================================================================

  /**
   * Set HVAC mode
   */
  public async climateSetHvacMode(entityId: string, hvacMode: string): Promise<void> {
    await this.callService('climate', 'set_hvac_mode', { entity_id: entityId }, { hvac_mode: hvacMode });
  }

  /**
   * Set target temperature
   */
  public async climateSetTemperature(entityId: string, options: IHomeAssistantClimateServiceData): Promise<void> {
    await this.callService('climate', 'set_temperature', { entity_id: entityId }, options);
  }

  /**
   * Set fan mode
   */
  public async climateSetFanMode(entityId: string, fanMode: string): Promise<void> {
    await this.callService('climate', 'set_fan_mode', { entity_id: entityId }, { fan_mode: fanMode });
  }

  /**
   * Set preset mode
   */
  public async climateSetPresetMode(entityId: string, presetMode: string): Promise<void> {
    await this.callService('climate', 'set_preset_mode', { entity_id: entityId }, { preset_mode: presetMode });
  }

  /**
   * Set swing mode
   */
  public async climateSetSwingMode(entityId: string, swingMode: string): Promise<void> {
    await this.callService('climate', 'set_swing_mode', { entity_id: entityId }, { swing_mode: swingMode });
  }

  /**
   * Set aux heat
   */
  public async climateSetAuxHeat(entityId: string, auxHeat: boolean): Promise<void> {
    await this.callService('climate', 'set_aux_heat', { entity_id: entityId }, { aux_heat: auxHeat });
  }

  // ==========================================================================
  // Cover Services
  // ==========================================================================

  /**
   * Open cover
   */
  public async coverOpen(entityId: string): Promise<void> {
    await this.callService('cover', 'open_cover', { entity_id: entityId });
  }

  /**
   * Close cover
   */
  public async coverClose(entityId: string): Promise<void> {
    await this.callService('cover', 'close_cover', { entity_id: entityId });
  }

  /**
   * Stop cover
   */
  public async coverStop(entityId: string): Promise<void> {
    await this.callService('cover', 'stop_cover', { entity_id: entityId });
  }

  /**
   * Set cover position
   */
  public async coverSetPosition(entityId: string, position: number): Promise<void> {
    await this.callService('cover', 'set_cover_position', { entity_id: entityId }, { position });
  }

  /**
   * Set cover tilt position
   */
  public async coverSetTiltPosition(entityId: string, tiltPosition: number): Promise<void> {
    await this.callService('cover', 'set_cover_tilt_position', { entity_id: entityId }, { tilt_position: tiltPosition });
  }

  // ==========================================================================
  // Fan Services
  // ==========================================================================

  /**
   * Turn on fan
   */
  public async fanTurnOn(entityId: string, options?: IHomeAssistantFanServiceData): Promise<void> {
    await this.callService('fan', 'turn_on', { entity_id: entityId }, options);
  }

  /**
   * Turn off fan
   */
  public async fanTurnOff(entityId: string): Promise<void> {
    await this.callService('fan', 'turn_off', { entity_id: entityId });
  }

  /**
   * Set fan percentage
   */
  public async fanSetPercentage(entityId: string, percentage: number): Promise<void> {
    await this.callService('fan', 'set_percentage', { entity_id: entityId }, { percentage });
  }

  /**
   * Set fan preset mode
   */
  public async fanSetPresetMode(entityId: string, presetMode: string): Promise<void> {
    await this.callService('fan', 'set_preset_mode', { entity_id: entityId }, { preset_mode: presetMode });
  }

  /**
   * Oscillate fan
   */
  public async fanOscillate(entityId: string, oscillating: boolean): Promise<void> {
    await this.callService('fan', 'oscillate', { entity_id: entityId }, { oscillating });
  }

  /**
   * Set fan direction
   */
  public async fanSetDirection(entityId: string, direction: 'forward' | 'reverse'): Promise<void> {
    await this.callService('fan', 'set_direction', { entity_id: entityId }, { direction });
  }

  // ==========================================================================
  // Lock Services
  // ==========================================================================

  /**
   * Lock
   */
  public async lockLock(entityId: string): Promise<void> {
    await this.callService('lock', 'lock', { entity_id: entityId });
  }

  /**
   * Unlock
   */
  public async lockUnlock(entityId: string): Promise<void> {
    await this.callService('lock', 'unlock', { entity_id: entityId });
  }

  /**
   * Open (if supported)
   */
  public async lockOpen(entityId: string): Promise<void> {
    await this.callService('lock', 'open', { entity_id: entityId });
  }

  // ==========================================================================
  // Switch Services
  // ==========================================================================

  /**
   * Turn on switch
   */
  public async switchTurnOn(entityId: string): Promise<void> {
    await this.callService('switch', 'turn_on', { entity_id: entityId });
  }

  /**
   * Turn off switch
   */
  public async switchTurnOff(entityId: string): Promise<void> {
    await this.callService('switch', 'turn_off', { entity_id: entityId });
  }

  /**
   * Toggle switch
   */
  public async switchToggle(entityId: string): Promise<void> {
    await this.callService('switch', 'toggle', { entity_id: entityId });
  }

  // ==========================================================================
  // Media Player Services
  // ==========================================================================

  /**
   * Play media
   */
  public async mediaPlayerPlay(entityId: string): Promise<void> {
    await this.callService('media_player', 'media_play', { entity_id: entityId });
  }

  /**
   * Pause media
   */
  public async mediaPlayerPause(entityId: string): Promise<void> {
    await this.callService('media_player', 'media_pause', { entity_id: entityId });
  }

  /**
   * Stop media
   */
  public async mediaPlayerStop(entityId: string): Promise<void> {
    await this.callService('media_player', 'media_stop', { entity_id: entityId });
  }

  /**
   * Next track
   */
  public async mediaPlayerNext(entityId: string): Promise<void> {
    await this.callService('media_player', 'media_next_track', { entity_id: entityId });
  }

  /**
   * Previous track
   */
  public async mediaPlayerPrevious(entityId: string): Promise<void> {
    await this.callService('media_player', 'media_previous_track', { entity_id: entityId });
  }

  /**
   * Set volume
   */
  public async mediaPlayerSetVolume(entityId: string, volumeLevel: number): Promise<void> {
    await this.callService('media_player', 'volume_set', { entity_id: entityId }, { volume_level: volumeLevel });
  }

  /**
   * Mute/unmute
   */
  public async mediaPlayerMute(entityId: string, isMuted: boolean): Promise<void> {
    await this.callService('media_player', 'volume_mute', { entity_id: entityId }, { is_volume_muted: isMuted });
  }

  /**
   * Seek to position
   */
  public async mediaPlayerSeek(entityId: string, position: number): Promise<void> {
    await this.callService('media_player', 'media_seek', { entity_id: entityId }, { seek_position: position });
  }

  /**
   * Select source
   */
  public async mediaPlayerSelectSource(entityId: string, source: string): Promise<void> {
    await this.callService('media_player', 'select_source', { entity_id: entityId }, { source });
  }

  // ==========================================================================
  // Camera Services
  // ==========================================================================

  /**
   * Get camera snapshot URL
   */
  public getCameraSnapshotUrl(entityId: string): string {
    const protocol = this.config.secure ? 'https' : 'http';
    const entity = this.entityStates.get(entityId);
    const accessToken = (entity?.attributes as { access_token?: string })?.access_token || '';
    return `${protocol}://${this.config.host}:${this.config.port}/api/camera_proxy/${entityId}?token=${accessToken}`;
  }

  /**
   * Get camera stream URL
   */
  public getCameraStreamUrl(entityId: string): string {
    const protocol = this.config.secure ? 'https' : 'http';
    return `${protocol}://${this.config.host}:${this.config.port}/api/camera_proxy_stream/${entityId}`;
  }

  // ==========================================================================
  // Static Helpers
  // ==========================================================================

  /**
   * Probe if a Home Assistant instance is reachable
   */
  public static async probe(host: string, port: number = 8123, secure: boolean = false, timeout: number = 5000): Promise<boolean> {
    return new Promise((resolve) => {
      const protocol = secure ? 'wss' : 'ws';
      const url = `${protocol}://${host}:${port}/api/websocket`;

      try {
        const ws = new plugins.WebSocket(url);

        const timer = setTimeout(() => {
          ws.close();
          resolve(false);
        }, timeout);

        ws.on('open', () => {
          // Wait for auth_required message
        });

        ws.on('message', (data: Buffer | string) => {
          const message = JSON.parse(data.toString()) as IHomeAssistantMessage;
          if (message.type === 'auth_required') {
            clearTimeout(timer);
            ws.close();
            resolve(true);
          }
        });

        ws.on('error', () => {
          clearTimeout(timer);
          resolve(false);
        });
      } catch {
        resolve(false);
      }
    });
  }
}