import { autoService, singleton, location } from 'knifecycle';
import { noop } from '../utils/utils.js';
import { type LogService } from './log.js';

export type TimeService = () => number;

/**
 * Instantiate the time service
 * @name initTime
 * @function
 * @param  {Object}   services           The services to inject
 * @param  {Object}   [services.log = noop]     A logging function
 * @return {Promise<Function>}           A promise of the time function
 * @example
 * import {
 *   DEFAULT_LOGGER,
 *   initLog,
 *   initTime,
 * } from 'common-services';
 *
 * const log = await initLog({
 *   logger: DEFAULT_LOGGER,
 * });
 *
 * const time = await initTime({
 *   log,
 * });
 */
async function initTime({
  log = noop,
}: {
  log?: LogService;
}): Promise<TimeService> {
  log('debug', '⏰ - Time service initialized.');

  return time;

  /**
   * Returns the current timestamp
   * @return {number}   The current timestamp
   * @example
   * time()
   * // Prints: 1326585600000
   */
  function time() {
    const now = Date.now();

    log('debug', '⏰ - Picked a timestamp:', now);
    return now;
  }
}

/* Architecture Note #1.2: Time

The `time` service is just proxying [`Date.now`
](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Date/now)
 in a mockable manner.
*/

export default location(singleton(autoService(initTime)), import.meta.url);