/**
 * @license
 *
 * Copyright 2019 Google LLC. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * ==============================================================================
 */

import * as utils from '../src/utils';
import Prando from 'prando';

describe('umap utils', () => {
  const prando = new Prando(42);
  const random = () => prando.next();

  test('norm function', () => {
    const results = utils.norm([1, 2, 3, 4]);
    expect(results).toEqual(Math.sqrt(30));
  });

  test('empty function', () => {
    const results = utils.empty(3);
    expect(results).toEqual([undefined, undefined, undefined]);
  });

  test('empty function', () => {
    const results = utils.empty(3);
    expect(results).toEqual([undefined, undefined, undefined]);
  });

  test('range function', () => {
    const results = utils.range(3);
    expect(results).toEqual([0, 1, 2]);
  });

  test('filled function', () => {
    const results = utils.filled(3, 5);
    expect(results).toEqual([5, 5, 5]);
  });

  test('zeros function', () => {
    const results = utils.zeros(3);
    expect(results).toEqual([0, 0, 0]);
  });

  test('ones function', () => {
    const results = utils.ones(3);
    expect(results).toEqual([1, 1, 1]);
  });

  test('linear function', () => {
    const results = utils.linear(0, 5, 5);
    expect(results).toEqual([0, 1.25, 2.5, 3.75, 5]);
  });

  test('sum function', () => {
    const results = utils.sum([1, 2, 3]);
    expect(results).toEqual(6);
  });

  test('mean function', () => {
    const results = utils.mean([1, 2, 3]);
    expect(results).toEqual(2);
  });

  test('max function', () => {
    const results = utils.max([1, 3, 2]);
    expect(results).toEqual(3);
  });

  test('max2d function', () => {
    const results = utils.max2d([[1, 2, 3], [4, 5, 6]]);
    expect(results).toEqual(6);
  });

  test('rejection sample', () => {
    const results = utils.rejectionSample(5, 10, random);
    const entries = new Set<number>();
    for (const r of results) {
      expect(entries.has(r)).toBe(false);
      entries.add(r);
    }
  });

  test('reshape2d function', () => {
    const input = [1, 2, 3, 4, 5, 6];
    expect(utils.reshape2d(input, 2, 3)).toEqual([[1, 2, 3], [4, 5, 6]]);
    expect(utils.reshape2d(input, 3, 2)).toEqual([[1, 2], [3, 4], [5, 6]]);

    expect(() => utils.reshape2d(input, 3, 3)).toThrow();
  });
});