import { Parse }              from 'parse/node';
import rest                   from '../rest';
import AdaptableController    from './AdaptableController';
import { PushAdapter }        from '../Adapters/Push/PushAdapter';
import deepcopy               from 'deepcopy';
import RestQuery              from '../RestQuery';
import RestWrite              from '../RestWrite';
import { master }             from '../Auth';
import { pushStatusHandler }  from '../StatusHandler';

const UNSUPPORTED_BADGE_KEY = "unsupported";

export class PushController extends AdaptableController {

  /**
   * 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 (Array.isArray(deviceTypeField['$in'])) {
      deviceTypes.concat(deviceTypeField['$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.');
      }
    }
  }

  get pushIsAvailable() {
    return !!this.adapter;
  }

  sendPush(body = {}, where = {}, config, auth, onPushStatusSaved = () => {}) {
    var pushAdapter = this.adapter;
    if (!this.pushIsAvailable) {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            'Push adapter is not available');
    }
    if (!this.options) {
      throw new Parse.Error(Parse.Error.PUSH_MISCONFIGURED,
                            'Missing push configuration');
    }
    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 = () => {
      return Promise.resolve();
    }
    if (body.data && body.data.badge) {
      let badge = body.data.badge;
      let restUpdate = {};
      if (typeof badge == 'string' && badge.toLowerCase() === 'increment') {
        restUpdate = { badge: { __op: 'Increment', amount: 1 } }
      } else if (Number(badge)) {
        restUpdate = { badge: badge }
      } else {
        throw "Invalid value for badge, expected number or 'Increment'";
      }
      let updateWhere = deepcopy(where);

      badgeUpdate = () => {
        updateWhere.deviceType = 'ios';
        // Build a real RestQuery so we can use it in RestWrite
        let restQuery = new RestQuery(config, master(config), '_Installation', updateWhere);
        return restQuery.buildRestWhere().then(() => {
          let write = new RestWrite(config, master(config), '_Installation', restQuery.restWhere, restUpdate);
          write.runOptions.many = true;
          return write.execute();
        });
      }
    }
    let pushStatus = pushStatusHandler(config);
    return Promise.resolve().then(() => {
      return pushStatus.setInitial(body, where);
    }).then(() => {
      onPushStatusSaved(pushStatus.objectId);
      return badgeUpdate();
    }).then(() => {
      return rest.find(config, auth, '_Installation', where);
    }).then((response) => {
      if (!response.results) {
        return Promise.reject({error: 'PushController: no results in query'})
      }
      pushStatus.setRunning(response.results);
      return this.sendToAdapter(body, response.results, pushStatus, config);
    }).then((results) => {
      return pushStatus.complete(results);
    }).catch((err) => {
      return pushStatus.fail(err).then(() => {
        throw err;
      });
    });
  }

  sendToAdapter(body, installations, pushStatus) {
    if (body.data && body.data.badge && typeof body.data.badge == 'string' && body.data.badge.toLowerCase() == "increment") {
      // Collect the badges to reduce the # of calls
      let badgeInstallationsMap = installations.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.data.badge;
        } else {
          payload.data.badge = parseInt(badge);
        }
        return this.adapter.send(payload, badgeInstallationsMap[badge], pushStatus.objectId);
      });
      return Promise.all(promises);
    }
    return this.adapter.send(body, installations, pushStatus.objectId);
  }

  /**
   * 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;