"use strict";

const Promise = require("bluebird");
const ms = require("ms");
const promiseDelaySince = require("@joepie91/promise-delay-every");
const propagateAbort = require("@ppstreams/propagate-abort");

module.exports = function rateLimitedStream(interval) {
	let intervalInMilliseconds = (typeof interval === "number")
		? interval
		: ms(interval);

	let delayer = promiseDelaySince(intervalInMilliseconds);

	return {
		description: `rate-limited stream (1 per ${interval})`,
		read: (source) => {
			return Promise.try(() => {
				return delayer();
			}).then(() => {
				return source.read();
			});
		},
		abort: propagateAbort
	}
};