import { API, CharacteristicValue, PlatformAccessory, Service, Characteristic } from 'homebridge';
import { SmartHQClient, DeviceService } from 'ge-smarthq-api';
import { SmartHqPlatform } from '../platform.js';


/**
 * Platform Accessory
 * An instance of this class is created for each accessory your platform registers
 * Each accessory may expose multiple services of different service types.
 */
export class EnergySensor {

private client: SmartHQClient;
public readonly Service: typeof Service;
public readonly Characteristic: typeof Characteristic;
private readonly api: API;
private prevKwhReading: number = 0;

constructor(
    private readonly platform: SmartHqPlatform,
    private readonly accessory: PlatformAccessory,
    public readonly deviceServices: DeviceService[],
    public readonly deviceId: string,
    ) {

    this.api = platform.api; 
    this.Service = this.api.hap.Service;
    this.Characteristic = this.api.hap.Characteristic;
    this.accessory = accessory;
    this.deviceServices = deviceServices;
    this.deviceId = deviceId;
    this.client = new SmartHQClient({
      clientId:       platform.config.clientId,
      clientSecret:   platform.config.clientSecret,
      redirectUri:    platform.config.redirectUri,
      debug:          platform.config.debugLogging || false,
    });

  //=====================================================================================
  // Check to see if the device has any supported Energy Sensor services
  // If not, then don't add a service for device that doesn't support it
  //=====================================================================================
  let hasEnergyMeter = false;
  for (const service of deviceServices) {
    if (service.serviceDeviceType === 'cloud.smarthq.device.meter'
      && service.serviceType      === 'cloud.smarthq.service.meter'
      && service.domainType       === 'cloud.smarthq.domain.energy') {
      hasEnergyMeter = true;
    }
  }
  if (!hasEnergyMeter) {
    this.client.debug('No supported Energy Meter service found for device: ' + this.accessory.displayName);
    return;
  }
  this.client.debug('Adding an Energy Sensor');

  //=====================================================================================
  // create a new water FilterMaintenance service for the Refrigerator
  // This works in Homebridge and HomeKit has a native FilterMaintenance service type but the Home app does not implement it yet 
  // so no sensor/accessory will show up in the Home app for this service type.
  //===================================================================================== 
  const displayName = "Watts/hr";
  const energySensor = this.accessory.getService(displayName) 
  || this.accessory.addService(this.Service.TemperatureSensor, displayName,  `${this.deviceId}-energy1`);
  energySensor.addOptionalCharacteristic(this.Characteristic.ConfiguredName)
  energySensor.setCharacteristic(this.Characteristic.ConfiguredName, displayName)

  const energyCurrent = energySensor.getCharacteristic(this.Characteristic.CurrentTemperature);

  //=====================================================================================
  // Now modify the properties for each characteristic to make the temperature sensor
  // function as an energy readout in kWh
  //=====================================================================================
  try {
    energyCurrent.setProps({
      unit: 'kWh',
      minValue: -30.0,
      maxValue: 50000000.0,
      minStep: 1.0
    });
  } catch (error) {
    this.client.debug('Error setting Energy sensor properties: ' + error);
  }

  //energySensor.getCharacteristic(this.Characteristic.CurrentTemperature)
  //  .onGet(this.getEnergyChange.bind(this));
  //=====================================================================================
  // Poll every 1800 seconds for new energy data
  //=====================================================================================
  setInterval(() => {
    this.getEnergyChange().then(temp => {
      energySensor.getCharacteristic(this.Characteristic.CurrentTemperature).updateValue(temp);
    });
  }, 30 * 60 * 1000);

}
//=====================================================================================
  async getEnergyChange(): Promise<CharacteristicValue> {
    let kwhReading = 0
    for (const service of this.deviceServices) {
      if (service.serviceDeviceType === 'cloud.smarthq.device.meter' 
        && service.serviceType      === 'cloud.smarthq.service.meter') {
        try { 
          const response = await this.client.getServiceDetails(this.deviceId, service.serviceId);
          if (response?.state?.meterValue == null) {
            this.client.debug('No state.meterValue returned from getEnergyChange state');
            return false;
          }
          kwhReading = Number(response?.state?.meterValue);
          const intervalDelta = kwhReading - this.prevKwhReading;
          kwhReading = (intervalDelta * 2 - 32) / 1.8;  // Interval is 30 minutes so double to get hourly rate
          this.prevKwhReading = Number(response?.state?.meterValue);
          break;
        } catch (error) {
          this.client.debug('Error getting Energy Meter value: ' + error);
          return false; 
        }
      }
    }
    return kwhReading * 2; // Interval is 30 minutes so double to get hourly rate
  }
};