'use strict';

import chai from 'chai';
const assert = chai.assert;
import BB from '../../lib/indicator/bollinger-bands.js';

describe('Boilinger Bands', () => {

	let data = [25.5, 26.75, 27.0, 26.5, 27.25];
	let data_2 = [25.5, 26.75, 27.0, 26.5, 27.25, 28.1];

	it('should calculate correctly and return result', () => {
		let runTest = async (periods, values, expectedResult) => {
			let opts = { periods, lazyEvaluation: true, sliceOffset: true };
			let bb = new BB(opts);
			bb.setValues(values);
			let results = await bb.calculate();

			assert.isArray(results)
			assert.isTrue(values.length - opts.periods + 1 == results.length);

			expectedResult.forEach((expected, idx) => {
				let resultItem = results[idx];
				assert.isObject(resultItem);
				assert.containsAllKeys(resultItem, ['upper', 'middle', 'lower', 'price']);
				assert.closeTo(resultItem.upper, expected.u, 0.1);
				assert.closeTo(resultItem.middle, expected.m, 0.1);
				assert.closeTo(resultItem.lower, expected.l, 0.1);
				assert.isTrue(resultItem.price == values[periods - 1 + idx]);
			});
		};

		let arr = [
			{
				p: 5, v: data, e: [
					{ m: 26.6, u: 27.8, l: 25.4 }
				]
			},
			{
				p: 5, v: data_2, e: [
					{ m: 26.6, u: 27.8, l: 25.4 },
					{ m: 27.1, u: 28.2, l: 26.0 }
				]
			},
		];

		for (let i = 0; i < arr.length; i++) {
			let item = arr[i];
			runTest(item.p, item.v, item.e);
		}

	});



	it('should calculate correctly and return results with offset', () => {
		let runTest = async (periods, values, expectedResult) => {
			let opts = { periods, sliceOffset: false, lazyEvaluation: true };
			let bb = new BB(opts);
			bb.setValues(values);
			let results = await bb.calculate();

			assert.isArray(results)
			assert.isTrue(values.length == results.length);

			expectedResult.forEach((expected, idx) => {
				let resultItem = results[idx];
				assert.containsAllKeys(resultItem, ['upper', 'middle', 'lower', 'price']);
				assert.closeTo(resultItem.upper, expected.u, 0.1);
				assert.closeTo(resultItem.middle, expected.m, 0.1);
				assert.closeTo(resultItem.lower, expected.l, 0.1);
				assert.isTrue(resultItem.price == values[idx]);
			});
		};

		let arr = [
			{
				p: 5, v: data, e: [
					{ m: 0, u: 0, l: 0 },
					{ m: 0, u: 0, l: 0 },
					{ m: 0, u: 0, l: 0 },
					{ m: 0, u: 0, l: 0 },
					{ m: 26.6, u: 27.8, l: 25.4 }
				]
			}
		];

		for (let i = 0; i < arr.length; i++) {
			let item = arr[i];
			runTest(item.p, item.v, item.e);
		}
	});


	it('should throw error on invalid options', () => {
		function runTest(opts) {
			let bb = new BB(opts);
			bb.setValues(data);
			assert.throws(() => bb.calculate(), Error);
		};

		[
			{ periods: data.length + 1 },
			{ startIndex: data.length + 1 },
			{ endIndex: data.length + 1 },
			{ periods: 'foo' },
			{ startIndex: data.length, endIndex: 0 },
		].forEach((option) => runTest(option));

	});

});