import { EventEmitter } from 'events';
import { IBedHardware, PinState, PinChange } from '../types/bedhardware';
import MQTT from '../adapter/mqtt';
import { getMQTTClient, BASE_TOPIC } from './mqttService';

export interface MqttConfig {
  topics?: {
    pinState: string;
    pinChange: string;
    initialization: string;
  };
}

export class BedHardwareMQTT extends EventEmitter implements IBedHardware {
  private client: MQTT | null = null;
  private pinStates: Map<number, PinState> = new Map();
  private connectionState: boolean = false;
  private topics: {
    pinState: string;
    pinChange: string;
    initialization: string;
  };

  constructor(private config: MqttConfig = {}) {
    super();
    this.topics = config.topics || {
      pinState: `${BASE_TOPIC}pin/state`,
      pinChange: `${BASE_TOPIC}pin/change`,
      initialization: `${BASE_TOPIC}init`
    };
  }
  async connect(): Promise<void> {
    try {
      // Use the MQTT service to get a client connected to HiveMQ
      this.client = await getMQTTClient();
      
      // Subscribe to topics - adapter handles reconnection/resubscription
      await this.client.subscribe(this.topics.initialization, (topic, message) => {
        this.handleMqttMessage(topic, message);
      });

      await this.client.subscribe(this.topics.pinState, (topic, message) => {
        this.handleMqttMessage(topic, message);
      });

      await this.client.subscribe(this.topics.pinChange, (topic, message) => {
        this.handleMqttMessage(topic, message);
      });
      
      this.connectionState = true;
      this.emit('connected');
      console.log('BedHardware MQTT connected to HiveMQ');

    } catch (error) {
      const errorMsg = `Failed to connect to MQTT broker: ${error}`;
      console.error(errorMsg);
      this.emit('error', new Error(errorMsg));
      throw new Error(errorMsg);
    }
  }  async disconnect(): Promise<void> {
    if (this.client) {
      await this.client.disconnect();
    }
    this.client = null;
    this.connectionState = false;
    this.emit('disconnected');
  }

  private handleMqttMessage(topic: string, message: string): void {
    try {
      const data = JSON.parse(message);

      if (topic === this.topics.initialization) {
        if (data.type === 'START') {
          this.emit('initialized');
          console.log('MQTT initialization started');
        } else if (data.type === 'PIN_INIT' && data.pin !== undefined && data.state !== undefined) {
          const pinState: PinState = {
            pin: data.pin,
            state: data.state,
            name: data.name || `PIN${data.pin}`,
            timestamp: new Date(data.timestamp || Date.now())
          };
          
          this.pinStates.set(data.pin, pinState);
          this.emit('pinInitialized', pinState);
        }
      } else if (topic === this.topics.pinChange) {
        if (data.pin !== undefined && data.previousState !== undefined && data.currentState !== undefined) {
          const pinChange: PinChange = {
            pin: data.pin,
            previousState: data.previousState,
            currentState: data.currentState,
            timestamp: new Date(data.timestamp || Date.now())
          };
          
          // Update stored pin state
          const pinState: PinState = {
            pin: data.pin,
            state: data.currentState,
            name: data.name || `PIN${data.pin}`,
            timestamp: new Date(data.timestamp || Date.now())
          };
          
          this.pinStates.set(data.pin, pinState);
          
          this.emit('pinChanged', pinChange);
          this.emit(`pin${data.pin}Changed`, pinChange);
        }
      } else if (topic === this.topics.pinState) {
        if (data.pin !== undefined && data.state !== undefined) {
          const pinState: PinState = {
            pin: data.pin,
            state: data.state,
            name: data.name || `PIN${data.pin}`,
            timestamp: new Date(data.timestamp || Date.now())
          };
          
          this.pinStates.set(data.pin, pinState);
          this.emit('pinInitialized', pinState);
        }
      }
    } catch (error) {
      console.error('Error parsing MQTT message:', error);
      this.emit('error', new Error(`Failed to parse MQTT message: ${error}`));
    }
  }

  getPinState(pin: number): PinState | undefined {
    return this.pinStates.get(pin);
  }

  getAllPinStates(): PinState[] {
    return Array.from(this.pinStates.values());
  }

  isConnected(): boolean {
    return this.connectionState;
  }
}