import { Injectable } from "@angular/core";
import Gun from "gun/gun";
import "gun/lib/then";

/*
  Generated class for the P2pDatabaseGunProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class P2pDatabaseGunProvider {
  private gun;
  osnPrefix: string = "hybridOSN-beta001";

  constructor() {
    this.gun = Gun();
  }

  public storeLastTweetHashForUser(userId, hash, timestamp): void {
    const tweet = this.gun
      .get(timestamp)
      .put({ hash: hash, created_at: timestamp });
    this.gun
      .get(this.osnPrefix + "-" + userId)
      .get("tweets")
      .set(tweet);
  }

  public async getLastTweetFromUser(userId) {
    return new Promise(resolve =>
      this.gun
        .get(this.osnPrefix + userId)
        .get("tweets")
        .once(resolve)
    );
  }

  public async fetchPrivateTweetHashsForUserInInterval(
    userId,
    intervalStart,
    intervalEnd
  ): Promise<object[]> {
    const gunIds = await this.gun
      .get(this.osnPrefix + "-" + userId)
      .get("tweets")
      .then();

    if (gunIds) {
      const entries = await Promise.all(
        Object.keys(gunIds)
          .filter(key => key !== "_")
          .map(key => this.gun.get(key).then())
      );

      return entries.filter(
        entry =>
          new Date(entry["created_at"]) < intervalStart &&
          new Date(entry["created_at"]) >= intervalEnd
      );
    } else {
      return [];
    }
  }

  /**
   * Hashtags are stored without reference to the users to provide these information on an extra dashboard to twitter
   * @param hashtagEntity extracted hashtags
   */
  public publishHashtags(hashtagEntity): void {
    const timestamp = Date.now();
    const hashtagsCommaSeparated = hashtagEntity
      .map(el => el.hashtag)
      .sort()
      .join("|");

    const hashtags = this.gun.get(timestamp).put({
      hashtags: hashtagsCommaSeparated,
      created_at: timestamp
    });

    this.gun
      .get(this.osnPrefix)
      .get("hashtags")
      .set(hashtags);
  }
}