'use strict';

import convertHrtime from 'convert-hrtime';
import TypeUtil from '../utils/type.js';

export default {

	_handleGenerator(gen) {
		if (!this._options.lazyEvaluation) return gen.next().value;
		return new Promise((resolve, reject) => {
			let results = [];
			let maxTickDuration = this._options.maxTickDuration || 10;

			(function handler() {
				let startHRTime = process.hrtime();
				let obj = gen.next();
				let nextCall = false;
				while (!obj.done) {
					results.push(obj.value);
					let { milliseconds } = convertHrtime(process.hrtime(startHRTime));
					if (milliseconds < maxTickDuration) {
						obj = gen.next();
					} else {
						nextCall = true;
						break;
					}
				}
				(nextCall) ? setImmediate(() => handler()) : resolve(results);
			})();
		});
	},

	_handleAsyncGenerator(gen) {
		return new Promise((resolve, reject) => {
			let results = [];
			let maxTickDuration = this._options.maxTickDuration || 0.5;

			(function handler() {
				let startHRTime = process.hrtime();
				(async function loop() {
					try {
						let obj = await gen.next();
						if (!obj.done) {
							results.push(obj.value);
							let { milliseconds } = convertHrtime(process.hrtime(startHRTime));
							if (milliseconds < maxTickDuration) loop();
							else setImmediate(() => handler());
						}
						else {
							if (!TypeUtil.isUndefined(obj.value)) {
								results.push(obj.value);
							}
							resolve(results);
						}
					}
					catch (err) {
						reject(err);
					}
				})();
			})();
		});

	},
};