hc-sdk/src/trade_aggregation_call_builder.js

hc-sdk is a library for working with the HuaChain Horizon server.

import { CallBuilder } from './call_builder';
import { BadRequestError } from './errors';

const allowedResolutions = [
  60000,
  300000,
  900000,
  3600000,
  86400000,
  604800000
];

/**
 * Trade Aggregations facilitate efficient gathering of historical trade data.
 * Do not create this object directly, use {@link Server#tradeAggregation}.
 *
 * @class TradeAggregationCallBuilder
 * @extends CallBuilder
 * @constructor
 * @param {string} serverUrl serverUrl Horizon server URL.
 * @param {Asset} base base asset
 * @param {Asset} counter counter asset
 * @param {long} start_time lower time boundary represented as millis since epoch
 * @param {long} end_time upper time boundary represented as millis since epoch
 * @param {long} resolution segment duration as millis since epoch. *Supported values are 1 minute (60000), 5 minutes (300000), 15 minutes (900000), 1 hour (3600000), 1 day (86400000) and 1 week (604800000).
 * @param {long} offset segments can be offset using this parameter. Expressed in milliseconds. *Can only be used if the resolution is greater than 1 hour. Value must be in whole hours, less than the provided resolution, and less than 24 hours.
 */
export class TradeAggregationCallBuilder extends CallBuilder {
  constructor(
    serverUrl,
    base,
    counter,
    start_time,
    end_time,
    resolution,
    offset
  ) {
    super(serverUrl);

    this.url.segment('trade_aggregations');
    if (!base.isNative()) {
      this.url.setQuery('base_asset_type', base.getAssetType());
      this.url.setQuery('base_asset_code', base.getCode());
      this.url.setQuery('base_asset_issuer', base.getIssuer());
    } else {
      this.url.setQuery('base_asset_type', 'native');
    }
    if (!counter.isNative()) {
      this.url.setQuery('counter_asset_type', counter.getAssetType());
      this.url.setQuery('counter_asset_code', counter.getCode());
      this.url.setQuery('counter_asset_issuer', counter.getIssuer());
    } else {
      this.url.setQuery('counter_asset_type', 'native');
    }
    if (typeof start_time === 'undefined' || typeof end_time === 'undefined') {
      throw new BadRequestError('Invalid time bounds', [start_time, end_time]);
    } else {
      this.url.setQuery('start_time', start_time);
      this.url.setQuery('end_time', end_time);
    }
    if (!this.isValidResolution(resolution)) {
      throw new BadRequestError('Invalid resolution', resolution);
    } else {
      this.url.setQuery('resolution', resolution);
    }
    if (!this.isValidOffset(offset, resolution)) {
      throw new BadRequestError('Invalid offset', offset);
    } else {
      this.url.setQuery('offset', offset);
    }
  }

  /**
   * @private
   * @param {long} resolution Trade data resolution in milliseconds
   * @returns {boolean} true if the resolution is allowed
   */
  isValidResolution(resolution) {
    let found = false;

    for (let i = 0; i < allowedResolutions.length; i += 1) {
      if (allowedResolutions[i] === resolution) {
        found = true;
        break;
      }
    }
    return found;
  }

  /**
   * @private
   * @param {long} offset Time offset in milliseconds
   * @param {long} resolution Trade data resolution in milliseconds
   * @returns {boolean} true if the offset is valid
   */
  isValidOffset(offset, resolution) {
    const hour = 3600000;
    return !(offset > resolution || offset >= 24 * hour || offset % hour !== 0);
  }
}