./datasources/lastfm

index.ts

import { RequestOptions, RESTDataSource } from "apollo-datasource-rest";
import { ApolloError, AuthenticationError } from "apollo-server";

// Local Types
export type IResourceTypes = "album" | "artist" | "track" | "user";
export type IMethodTypes =
  | "getInfo"
  | "getTags"
  | "search"
  | "getSimilar"
  | "getTopTags"
  | "getTopAlbums"
  | "getTopArtists"
  | "getTopTracks"
  | "getLovedTracks"
  | "getRecentTracks"
  | "getFriends";

export interface ILastFMOptions {
  resource: IResourceTypes;
  method: IMethodTypes;
  [key: string]: any;
}

/**
 * LastFM
 */
class LastFM extends RESTDataSource {
  constructor() {
    super();
    this.baseURL = "http://ws.audioscrobbler.com/2.0";
  }

  public willSendRequest(request: RequestOptions) {
    if (!process.env.LASTFM_API_KEY) {
      throw new AuthenticationError(
        "Must configure a valid Last.fm API_KEY in your environment variables."
      );
    }
    request.params.set("api_key", process.env.LASTFM_API_KEY);
    request.params.set("format", "json");
  }

  public async call({ resource, method, ...options }: ILastFMOptions) {
    const query = Object.keys(options)
      .reduce(
        (querystring: string[], key: string): string[] => {
          querystring.push(`${key}=${options[key]}`);
          return querystring;
        },
        [`method=${resource}.${method}`]
      )
      .join("&");

    try {
      return this.get("", query);
    } catch (err) {
      throw new ApolloError(err);
    }
  }
}

export { LastFM };