const assert = require('assert');
const should = require('should');
const randomDecision = require('../random-decision');

describe('randomDecision', function () {
    describe('#getRandomChoice()', function () {
        it(`should return one of available choices`, function () {
            randomDecision.getRandomChoice().should.equalOneOf(randomDecision.choices);
        });

        it('should return the first choice sometimes', function () {
            const expectedChoice = randomDecision.choices[0];
            const selectedChoices = new Set();
            for (let i = 0; i <= 1000; i++) {
                const decision = randomDecision.getRandomChoice();
                selectedChoices.add(decision);
                if (decision === expectedChoice) {
                    should.ok(decision, 'First choice was found once');
                    return;
                }
            }
            should.fail(selectedChoices, expectedChoice, 'First choice was never selected');
        })
        it('should return the last choice sometimes', function () {
            const expectedChoice = randomDecision.choices[randomDecision.choices.length - 1];
            const selectedChoices = new Set();
            for (let i = 0; i <= 1000; i++) {
                const decision = randomDecision.getRandomChoice();
                selectedChoices.add(decision);
                if (decision === expectedChoice) {
                    should.ok(decision, 'Last choice was found once');
                    return;
                }
            }
            should.fail(selectedChoices, expectedChoice, 'Last choice was never selected');
        })
    })
    describe('#getRandomChoice(seed)', function () {
        it('should always select the same value when the seed is the same', function () {
            const seed = new Date();
            const initialDecision = randomDecision.getRandomChoice(seed);
            for (let i = 0; i <= 1000; i++) {
                let randomChoice = randomDecision.getRandomChoice(seed);
                assert.strictEqual(randomChoice, initialDecision);
            }
        })
    })
})