import fetch from 'node-fetch';
import { API, DynamicPlatformPlugin, Logger, PlatformAccessory, PlatformConfig, Service, Characteristic } from 'homebridge';

import { PLATFORM_NAME, PLUGIN_NAME } from './settings';
import { RadiantCoolingZoneAccessory } from './platformAccessory';
import { URLSearchParams } from 'url';

/**
 * HomebridgePlatform
 * This class is the main constructor for your plugin, this is where you should
 * parse the user config and discover/register accessories with Homebridge.
 */
export class RadiantCoolingPlatformPlugin implements DynamicPlatformPlugin {
  public readonly Service: typeof Service = this.api.hap.Service;
  public readonly Characteristic: typeof Characteristic = this.api.hap.Characteristic;

  // this is used to track restored cached accessories
  public readonly accessories: PlatformAccessory[] = [];
  private messanaRequestHeaders;

  constructor(
    public readonly log: Logger,
    public readonly config: PlatformConfig,
    public readonly api: API,
  ) {
    if (this.config.bearer === undefined) {
      this.log.error('Plugin could not be initialized. Enter Bearer for Messana api in plugin configuration');
      return;
    }
    this.messanaRequestHeaders = {
      'authorization': 'Bearer ' + this.config.bearer,
    };

    // When this event is fired it means Homebridge has restored all cached accessories from disk.
    // Dynamic Platform plugins should only register new accessories after this event was fired,
    // in order to ensure they weren't added to homebridge already. This event can also be used
    // to start discovery of new accessories.
    this.api.on('didFinishLaunching', () => {
      log.debug('Executed didFinishLaunching callback');
      // run the method to discover / register your devices as accessories
      this.discoverDevices();
    });
  }

  messanaApiFetch(urlPath: string) {
    return fetch('http://'+ this.config.messanaHostNameOrIP + '/api/' + urlPath, {
      'headers': this.messanaRequestHeaders,
    },
    ).then(resp => resp.json());
  }

  messanaApiPut(urlPath: string, params) {
    fetch('http://'+ this.config.messanaHostNameOrIP + '/api/' + urlPath, {
      method: 'PUT',
      'headers': this.messanaRequestHeaders,
      body: new URLSearchParams(params),
    });
  }

  /**
   * This function is invoked when homebridge restores cached accessories from disk at startup.
   * It should be used to setup event handlers for characteristics and update respective values.
   */
  configureAccessory(accessory: PlatformAccessory) {
    this.log.info('Loading accessory from cache:', accessory.displayName);

    // add the restored accessory to the accessories cache so we can track if it has already been registered
    this.accessories.push(accessory);
  }

  /**
   * This is an example method showing how to register discovered accessories.
   * Accessories must only be registered once, previously created accessories
   * must not be registered again to prevent "duplicate UUID" errors.
   */
  discoverDevices() {
    this.messanaApiFetch('system/zoneCount')
      .then(json => {
        const numZones = json['count'];
        this.log.info('Found %s zones', numZones);
        for (let i = 0; i < numZones; i++) {
          // generate a unique id for the accessory this should be generated from
          // something globally unique, but constant, for example, the device serial
          // number or MAC address
          const uuid = this.api.hap.uuid.generate('radiantcooling-' + i);
          this.log.debug('uuid: ', uuid);

          // see if an accessory with the same uuid has already been registered and restored from
          // the cached devices we stored in the `configureAccessory` method above
          const existingAccessory = this.accessories.find(accessory => accessory.UUID === uuid);

          if (existingAccessory) {
            // the accessory already exists
            this.log.info('Restoring existing accessory from cache:', existingAccessory.displayName);

            // create the accessory handler for the restored accessory
            // this is imported from `platformAccessory.ts`
            // new RadiantCoolingZoneAccessory(this, existingAccessory);

            // it is possible to remove platform accessories at any time using `api.unregisterPlatformAccessories`, eg.:
            // remove platform accessories when no longer present
            this.api.unregisterPlatformAccessories(PLUGIN_NAME, PLATFORM_NAME, [existingAccessory]);
            this.log.info('Removing existing accessory from cache:', existingAccessory.displayName);
          }
          // the accessory does not yet exist, so we need to create it
          this.messanaApiFetch('zone/name/' + i)
            .then(json => {
              const name = json['name'];
              this.log.info('Adding new accessory:', name);
              // create a new accessory
              const accessory = new this.api.platformAccessory(name, uuid);
              // create the accessory handler for the newly create accessory
              // this is imported from `platformAccessory.ts`
              new RadiantCoolingZoneAccessory(this, accessory, i);
              // link the accessory to your platform
              this.api.registerPlatformAccessories(PLUGIN_NAME, PLATFORM_NAME, [accessory]);
            });
        }
      });
  }
}