import { expect } from "chai";
import { describe, it } from "mocha";
import {
  avg,
  max,
  maxValueIndex,
  min,
  minValueIndex,
  pairing,
  pickRandom,
  randBoolean,
  randDouble,
  randInt,
  removeFromArray,
  shuffle,
  sum,
} from "../../../src/utils/Utils";

describe("Utils", () => {
  it("pick random", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const elem: number = pickRandom(arr);
    expect(arr.includes(elem)).to.be.true;
  });

  it("randInt", () => {
    for (let i = 0; i < 100; i++) {
      const int: number = randInt(-50, 50);

      expect(int).to.be.below(50);
      expect(int).to.be.above(-51);
    }
  });

  it("randDouble", () => {
    for (let i = 0; i < 100; i++) {
      const double: number = randDouble(-50, 50);

      expect(double).to.be.below(50);
      expect(double).to.be.above(-51);
    }
  });

  it("randBoolean", () => {
    let trues = 0;
    let falses = 0;
    for (let i = 0; i < 1000; i++) {
      const bool: boolean = randBoolean();
      if (bool) {
        trues++;
      } else {
        falses++;
      }
    }
    expect(trues).to.be.closeTo(falses, 100);
  });

  it("remove from array", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    expect(removeFromArray(arr, 200)).to.be.false;
    expect(removeFromArray(arr, arr[0])).to.be.true;

    const len: number = arr.length;
    expect(removeFromArray(arr, arr[2])).to.be.true;
    expect(arr.length).equals(len - 1);
  });

  it("shuffle", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const copy: number[] = arr.slice();
    shuffle(copy);

    expect(copy.length).to.be.equals(arr.length);
    copy.forEach((element) => expect(arr).includes(element));
  });

  it("max", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const maxValue: number = max(arr);

    arr.forEach((elem) => expect(elem).to.be.at.most(maxValue));
  });

  it("max index", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const maxValue: number = max(arr);

    expect(maxValueIndex(arr)).to.be.equals(arr.indexOf(maxValue));
  });

  it("min", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const minValue: number = min(arr);

    arr.forEach((elem) => expect(elem).to.be.at.least(minValue));
  });

  it("min index", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    const minValue: number = min(arr);

    expect(minValueIndex(arr)).to.be.equals(arr.indexOf(minValue));
  });

  it("avg", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    let sum = 0;
    arr.forEach((elem) => (sum += elem));
    expect(avg(arr)).to.be.equals(sum / arr.length);
  });

  it("sum", () => {
    const arr: number[] = [
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
      randDouble(-50, 50),
    ];

    let sumValue = 0;
    arr.forEach((elem) => (sumValue += elem));
    expect(sum(arr)).to.be.equals(sumValue);
  });

  describe("Utils pairing", () => {
    const a: number = randInt(0, 100);
    const b: number = randInt(0, 100);

    it(`util.getCantorNumber(a=${a}, b=${b}) => {number}`, () => {
      expect(pairing(a, b)).to.be.a("number");
    });
    // Critical, avoids silent errors
    it("(-number, -number) => -1", () => {
      expect(() => pairing(-1, -1)).to.throw("Should be a positive integer!");
    });
  });
});