thecodingmachine / DBFaker

src/Helpers/NumericColumnLimitHelper.php

<?php
namespace DBFaker\Helpers;

use DBFaker\Exceptions\UnsupportedDataTypeException;
use Doctrine\DBAL\Schema\Column;
use Doctrine\DBAL\Types\Type;

/**
 * Class NumericColumnLimitHelper: gives the min and max numeric values for a column depending
 * on it's type and attributes (precision, scale, unsigned)
 *
 * @package DBFaker\Helpers
 */
class NumericColumnLimitHelper
{

    /**
     * @var Column
     */
    private $column;

    private static $handledNumberTypes = [
        Type::BIGINT,
        Type::DECIMAL,
        Type::INTEGER,
        Type::SMALLINT,
        Type::FLOAT
    ];

    /**
     * NumericColumnLimitHelper constructor
     * @param Column $column
     * @throws \DBFaker\Exceptions\UnsupportedDataTypeException
     */
    public function __construct(Column $column)
    {
        if (!\in_array($column->getType()->getName(), self::$handledNumberTypes, true)) {
            throw new UnsupportedDataTypeException('Unsupported column type : ' .
                $column->getType()->getName() . 'only ' .
                implode("', '", self::$handledNumberTypes) . ' types are supported.');
        }
        $this->column = $column;
    }

    /**
     * returns the min numeric value for the column
     * @return int|float|string
     */
    public function getMinNumericValue()
    {
        $precisionValue = $this->getAbsValueByLengthPrecision($this->column);
        switch ($this->column->getType()->getName()) {
            case Type::BIGINT:
                return $this->column->getUnsigned() ? 0 : bcmul('-1', bcpow('2', '63'));
                break;

break is not strictly necessary here and could be removed.

            case Type::INTEGER:
                return $this->column->getUnsigned() ? 0 : max(-1 * $precisionValue, bcmul('-1', bcpow('2', '31')));
                break;
            case Type::SMALLINT:
                return $this->column->getUnsigned() ? 0 : bcmul('-1', bcpow('2', '15'));
                break;
            case Type::DECIMAL:
                return $this->column->getUnsigned() ? 0 : -1 * $precisionValue;
                break;
            case Type::FLOAT:
                return $this->column->getUnsigned() ? 0 : -8.95e307;
                break;
        }
    }

    /**
     * returns the max numeric value for the column
     * @return int|float|string
     */
    public function getMaxNumericValue()
    {
        $precisionValue = $this->getAbsValueByLengthPrecision($this->column);
        switch ($this->column->getType()->getName()) {
            case Type::BIGINT:
                return $this->column->getUnsigned() ? bcsub(bcpow('2', '64'), '1') : bcsub(bcpow('2', '63'), '1');
            case Type::INTEGER:
                return $this->column->getUnsigned() ? bcsub(bcpow('2', '32'), '1') : min($precisionValue, bcsub(bcpow('2', '31'), '1'));
            case Type::SMALLINT:
                return $this->column->getUnsigned() ? bcsub(bcpow('2', '16'), '1') : bcsub(bcpow('2', '15'), '1');
            case Type::DECIMAL:
                return $this->column->getUnsigned() ? 0 : $precisionValue;
            case Type::FLOAT:
                return 8.95e307;
        }
    }

    /**
     * @param Column $column
     * @return double|int
     */
    private function getAbsValueByLengthPrecision(Column $column)
    {
        switch ($column->getType()->getName()) {
            case Type::DECIMAL:
                $str = str_repeat('9', $column->getScale());
                return (double) substr_replace($str, '.', $column->getScale() - $column->getPrecision(), 0);
            case Type::INTEGER:
                $str = str_repeat('9', $column->getPrecision() - 1);
                return (int) $str;
        }
    }
}