cryptowatch.js

const http = require("superagent");

const CW_STARTING_ALLOWANCE = 8000000000;

/**
 * @class CryptoWatch
 * Wrapper for cryptowat.ch api
 */

class CryptoWatch {
  /**
   * @constructor
   */

  constructor(url = "https://api.cryptowat.ch") {
    this.url = url;
    this._allowance = CW_STARTING_ALLOWANCE;
  }

  /**
   * Request helper function
   * @private
   */

  request(endpoint, params) {
    return new Promise((resolve, reject) => {
      const url = `${this.url}/${endpoint}`;
      http
        .get(url)
        .query(params)
        .end((err, res) => {
          if (err) {
            reject({
              message: "Request failed",
              error: String(err),
              url
            });
          } else {
            this._allowance = res.body.allowance.remaining;
            resolve(res.body.result);
          }
        });
    });
  }

  /**
   * Gets remaining api allowance.
   */

  allowance() {
    return this._allowance;
  }

  /**
   * Gets all assets (crypto or fiat currency).
   */

  assets() {
    return this.request("assets");
  }

  /**
   * Gets an asset's information.
   *
   * @param {String} name
   */

  asset(name) {
    return this.request(`assets/${name}`);
  }

  /**
   * Gets currency pairs info.
   */

  pairs() {
    return this.request("pairs");
  }

  /**
   * Gets info for a currency pair.
   *
   * @param {String} name
   */

  pair(name) {
    return this.request(`pairs/${name}`);
  }

  /**
   * Gets info for all the exchanges.
   *
   * @param {Boolean} [active] If true, only return active exchanges
   */

  exchanges(active = true) {
    return new Promise((resolve, reject) => {
      this.request("exchanges")
        .then(exchanges => {
          if (active) {
            exchanges = exchanges.filter(e => e.active);
          }
          resolve(exchanges);
        })
        .catch(reject);
    });
  }

  /**
   * Gets info for an exchange.
   *
   * @param {String} name
   */

  exchange(name) {
    return this.request(`exchanges/${name}`);
  }

  /**
   * Gets info for markets. Optionally specify a single exchange.
   *
   * @param {String} [exchange] Optional. Supply a specific exchange to get
   * markets for
   */

  markets(exchange = "") {
    let endpoint = "markets";
    if (exchange.length > 0) {
      endpoint = `${endpoint}/${exchange}`;
    }
    return this.request(endpoint);
  }

  /**
   * Gets info for a market given an exchange and pair.
   *
   * @param {String} exchange
   * @param {String} pair
   */

  market(exchange, pair) {
    return this.request(`markets/${exchange}/${pair}`);
  }

  /**
   * Returns price for a given market and currency pair.
   *
   * @param {String} market
   * @param {String} pair
   */

  price(market, pair) {
    return this.request(`markets/${market}/${pair}/price`);
  }

  /**
   * Aggregate endpoint that returns the current price for all supported
   * markets. Somes values may be out of date by a few seconds as results
   * are cached.
   */

  prices() {
    return this.request("markets/prices");
  }

  /**
   * Returns summary for a given market and currency pair.
   *
   * @param {String} market
   * @param {String} pair
   */

  summary(market, pair) {
    return this.request(`markets/${market}/${pair}/summary`);
  }

  /**
   * Aggregate endpoint that returns the market summary for all supported
   * markets. Some values may be out of date by a few seconds as results are
   * cached.
   */

  summaries() {
    return this.request("markets/summaries");
  }

  /**
   * Returns trades for a given market and currency pair.
   *
   * @param {String} market
   * @param {String} pair
   * @param {Object} [params]
   */

  trades(market, pair, params) {
    return this.request(`markets/${market}/${pair}/trades`, params);
  }

  /**
   * Returns the orderbook for a given market and currency pair.
   *
   * @param {String} market
   * @param {String} pair
   */

  orderbook(market, pair) {
    return this.request(`markets/${market}/${pair}/orderbook`);
  }

  /**
   * Returns a market’s OHLC candlestick data. Returns data as lists of lists
   * of numbers for each time period integer.
   *
   * @param {String} market
   * @param {String} pair
   * @param {Object} [params]
   */

  OHLC(market, pair, params) {
    return this.request(`markets/${market}/${pair}/ohlc`, params);
  }
}

module.exports = CryptoWatch;