ComboNthNum.php

<?php

/**
 * JBZoo Toolbox - Csv-Blueprint.
 *
 * This file is part of the JBZoo Toolbox project.
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 *
 * @license    MIT
 * @copyright  Copyright (C) JBZoo.com, All rights reserved.
 * @see        https://github.com/JBZoo/Csv-Blueprint
 */

declare(strict_types=1);

namespace JBZoo\CsvBlueprint\Rules\Aggregate;

use JBZoo\CsvBlueprint\Rules\AbstractRule;

use function JBZoo\Utils\float;

final class ComboNthNum extends AbstractAggregateRuleCombo
{
    public const INPUT_TYPE = AbstractRule::INPUT_TYPE_FLOATS;

    protected const NAME = 'N-th value';

    private const ARGS = 2;
    private const NTH = 0;
    private const VAL = 1;

    public function getHelpMeta(): array
    {
        return [
            [
                'N-th value in the column.',
                'The rule expects exactly two arguments: '
                . 'the first is the line number (without header), the second is the expected value.',
                'Example: `[ 42, 5.0 ]` On the line 42 (disregarding the header), we expect the 5.0. '
                . 'The comparison is always as float.',
            ],
            [
                self::MIN     => ['[ 42, 1.0 ]', 'x >= 1.0'],
                self::GREATER => ['[ 42, 2.0 ]', 'x >  2.0'],
                self::NOT     => ['[ 42, 5.0 ]', 'x != 5.0'],
                self::EQ      => ['[ 42, 7.0 ]', 'x == 7.0'],
                self::LESS    => ['[ 42, 8.0 ]', 'x <  8.0'],
                self::MAX     => ['[ 42, 9.0 ]', 'x <= 9.0'],
            ],
        ];
    }

    protected function getExpected(): float
    {
        return float($this->getParams()[self::VAL]);
    }

    protected function getActualAggregate(array $colValues): ?float
    {
        if (\count($colValues) === 0) {
            return null;
        }

        $realLine = (int)$this->getParams()[self::NTH];
        $arrayInd = $realLine - 1;
        $actual = $colValues[$arrayInd] ?? null;

        if ($actual === null) {
            throw new Exception(
                "The column does not have a line {$realLine}, so the value cannot be checked.",
            );
        }

        return float($actual);
    }

    protected static function calcValue(array $columnValues, ?array $options = null): null|float|int
    {
        return null;
    }

    private function getParams(): array
    {
        $params = $this->getOptionAsArray();
        if (\count($params) !== self::ARGS) {
            throw new Exception(
                'The rule expects exactly two arguments: '
                . 'the first is the line number (without header), the second is the expected value',
            );
        }

        return $params;
    }
}