<?php
declare(strict_types = 1);

namespace tests\Phpml\CrossValidation;

use Phpml\CrossValidation\RandomSplit;
use Phpml\Dataset\ArrayDataset;

class RandomSplitTest extends \PHPUnit_Framework_TestCase
{

    /**
     * @expectedException \Phpml\Exception\InvalidArgumentException
     */
    public function testThrowExceptionOnToSmallTestSize()
    {
        new RandomSplit(new ArrayDataset([], []), 0);
    }

    /**
     * @expectedException \Phpml\Exception\InvalidArgumentException
     */
    public function testThrowExceptionOnToBigTestSize()
    {
        new RandomSplit(new ArrayDataset([], []), 1);
    }

    public function testDatasetRandomSplitWithoutSeed()
    {
        $dataset = new ArrayDataset(
            $samples = [[1], [2], [3], [4]],
            $labels = ['a', 'a', 'b', 'b']
        );

        $randomSplit1 = new RandomSplit($dataset, 0.5);

        $this->assertEquals(2, count($randomSplit1->getTestSamples()));
        $this->assertEquals(2, count($randomSplit1->getTrainSamples()));

        $randomSplit2 = new RandomSplit($dataset, 0.25);

        $this->assertEquals(1, count($randomSplit2->getTestSamples()));
        $this->assertEquals(3, count($randomSplit2->getTrainSamples()));
    }

    public function testDatasetRandomSplitWithSameSeed()
    {
        $dataset = new ArrayDataset(
            $samples = [[1], [2], [3], [4], [5], [6], [7], [8]],
            $labels = ['a', 'a', 'a', 'a', 'b', 'b', 'b', 'b']
        );

        $seed = 123;

        $randomSplit1 = new RandomSplit($dataset, 0.5, $seed);
        $randomSplit2 = new RandomSplit($dataset, 0.5, $seed);

        $this->assertEquals($randomSplit1->getTestLabels(), $randomSplit2->getTestLabels());
        $this->assertEquals($randomSplit1->getTestSamples(), $randomSplit2->getTestSamples());
        $this->assertEquals($randomSplit1->getTrainLabels(), $randomSplit2->getTrainLabels());
        $this->assertEquals($randomSplit1->getTrainSamples(), $randomSplit2->getTrainSamples());
    }

    public function testDatasetRandomSplitWithDifferentSeed()
    {
        $dataset = new ArrayDataset(
            $samples = [[1], [2], [3], [4], [5], [6], [7], [8]],
            $labels = ['a', 'a', 'a', 'a', 'b', 'b', 'b', 'b']
        );

        $randomSplit1 = new RandomSplit($dataset, 0.5, 4321);
        $randomSplit2 = new RandomSplit($dataset, 0.5, 1234);

        $this->assertNotEquals($randomSplit1->getTestLabels(), $randomSplit2->getTestLabels());
        $this->assertNotEquals($randomSplit1->getTestSamples(), $randomSplit2->getTestSamples());
        $this->assertNotEquals($randomSplit1->getTrainLabels(), $randomSplit2->getTrainLabels());
        $this->assertNotEquals($randomSplit1->getTrainSamples(), $randomSplit2->getTrainSamples());
    }

    public function testRandomSplitCorrectSampleAndLabelPosition()
    {
        $dataset = new ArrayDataset(
            $samples = [[1], [2], [3], [4]],
            $labels = [1, 2, 3, 4]
        );

        $randomSplit = new RandomSplit($dataset, 0.5);

        $this->assertEquals($randomSplit->getTestSamples()[0][0], $randomSplit->getTestLabels()[0]);
        $this->assertEquals($randomSplit->getTestSamples()[1][0], $randomSplit->getTestLabels()[1]);
        $this->assertEquals($randomSplit->getTrainSamples()[0][0], $randomSplit->getTrainLabels()[0]);
        $this->assertEquals($randomSplit->getTrainSamples()[1][0], $randomSplit->getTrainLabels()[1]);
    }
    
}