"use strict";

const sortDependencies = require("../sort-dependencies");
const stream = require("../stream");

module.exports = function({ ignoreCycles }) {
	return function createKahnSortingStream() {
		let sortables = [];

		function handleItem(item) {
			sortables.push(item);
		}

		function flush() {
			let sorted = sortDependencies(sortables, {}, { ignoreCycles });

			// TODO: Verify that the 'null' push here is necessary
			return sorted.concat([ null ]);
		}

		return stream(handleItem, flush);
	};
};