import { Parse } from 'parse/node';
import PromiseRouter from '../PromiseRouter';
import rest from '../rest';
import AdaptableController from './AdaptableController';
import { PushAdapter } from '../Adapters/Push/PushAdapter';
import deepcopy from 'deepcopy';
import features from '../features';

const FEATURE_NAME = 'push';
const UNSUPPORTED_BADGE_KEY = "unsupported";

export class PushController extends AdaptableController {

  setFeature() {
    features.setFeature(FEATURE_NAME, this.adapter.feature || {});
  }

  /**
   * Check whether the deviceType parameter in qury condition is valid or not.
   * @param {Object} where A query condition
   * @param {Array} validPushTypes An array of valid push types(string)
   */
  static validatePushType(where = {}, validPushTypes = []) {
    var deviceTypeField = where.deviceType || {};
    var deviceTypes = [];
    if (typeof deviceTypeField === 'string') {
      deviceTypes.push(deviceTypeField);
    } else if (typeof deviceTypeField['$in'] === 'array') {
      deviceTypes.concat(deviceTypeField['$in']);
    }
    for (var i = 0; i < deviceTypes.length; i++) {
      var deviceType = deviceTypes[i];
      if (validPushTypes.indexOf(deviceType) < 0) {
        throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                              deviceType + ' is not supported push type.');
      }
    }
  }
  
  /**
   * Check whether the api call has master key or not.
   * @param {Object} request A request object
   */ 
  static validateMasterKey(auth = {}) {
    if (!auth.isMaster) {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            'Master key is invalid, you should only use master key to send push');
    }
  }

  sendPush(body = {}, where = {}, config, auth) {
    var pushAdapter = this.adapter;
    if (!pushAdapter) {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            'Push adapter is not available');
    }
    PushController.validateMasterKey(auth);
    PushController.validatePushType(where, pushAdapter.getValidPushTypes());
    // Replace the expiration_time with a valid Unix epoch milliseconds time
    body['expiration_time'] = PushController.getExpirationTime(body);
    // TODO: If the req can pass the checking, we return immediately instead of waiting
    // pushes to be sent. We probably change this behaviour in the future.
    let badgeUpdate = Promise.resolve();

    if (body.badge) {
      let op = {};
      if (body.badge == "Increment") {
        op = { $inc: { badge: 1 } }
      } else if (Number(body.badge)) {
        op = { $set: { badge: body.badge } }
      } else {
        throw "Invalid value for badge, expected number or 'Increment'";
      }
      let updateWhere = deepcopy(where);
      updateWhere.deviceType = 'ios'; // Only on iOS!

      badgeUpdate = config.database.adaptiveCollection("_Installation")
        .then(coll => coll.updateMany(updateWhere, op));
    }

    return badgeUpdate.then(() => {
      return rest.find(config, auth, '_Installation', where)
    }).then((response) => {
      if (body.badge && body.badge == "Increment") {
        // Collect the badges to reduce the # of calls
        let badgeInstallationsMap = response.results.reduce((map, installation) => {
          let badge = installation.badge;
          if (installation.deviceType != "ios") {
            badge = UNSUPPORTED_BADGE_KEY;
          }
          map[badge] = map[badge] || [];
          map[badge].push(installation);
          return map;
        }, {});
 
        // Map the on the badges count and return the send result
        let promises = Object.keys(badgeInstallationsMap).map((badge) => {
          let payload = deepcopy(body);
          if (badge == UNSUPPORTED_BADGE_KEY) {
            delete payload.badge;
          } else {
            payload.badge = parseInt(badge);
          }
          return pushAdapter.send(payload, badgeInstallationsMap[badge]); 
        });
        return Promise.all(promises);
      }
      return pushAdapter.send(body, response.results);
    });
  }
  
  /**
   * Get expiration time from the request body.
   * @param {Object} request A request object
   * @returns {Number|undefined} The expiration time if it exists in the request
   */
  static getExpirationTime(body = {}) {
    var hasExpirationTime = !!body['expiration_time'];
    if (!hasExpirationTime) {
      return;
    }
    var expirationTimeParam = body['expiration_time'];
    var expirationTime;
    if (typeof expirationTimeParam === 'number') {
      expirationTime = new Date(expirationTimeParam * 1000);
    } else if (typeof expirationTimeParam === 'string') {
      expirationTime = new Date(expirationTimeParam);
    } else {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            body['expiration_time'] + ' is not valid time.');
    }
    // Check expirationTime is valid or not, if it is not valid, expirationTime is NaN
    if (!isFinite(expirationTime)) {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            body['expiration_time'] + ' is not valid time.');
    }
    return expirationTime.valueOf();
  }

  expectedAdapterType() {
    return PushAdapter;
  }
};

export default PushController;