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<?php

/**
 * MvcCore
 *
 * This source file is subject to the BSD 3 License
 * For the full copyright and license information, please view
 * the LICENSE.md file that are distributed with this source code.
 *
 * @copyright   Copyright (c) 2016 Tom Flidr (https://github.com/mvccore)
 * @license  https://mvccore.github.io/docs/mvccore/5.0.0/LICENCE.md
 */

namespace MvcCore\Model;

trait Comparers {

    /**
     * Compare two values. Supported types are:
     *  - NULL
     *  - scalar (int, float, string, bool)
     *  - array
     *  - \stdClass
     *  - \DateTimeInterface, \DateInterval, \DateTimeZone, \DatePeriod
     *  - resource (only by `intval($value1) == intval($value2)`)
     *  - object instances (only by `===` comparison)
     * @param mixed $value1 
     * @param mixed $value2 
     * @return bool
     */
    protected static function isEqual ($value1, $value2) {
        $valuasAreTheSame = FALSE;
        $value1IsNull = $value1 === NULL;
        $value2IsNull = $value2 === NULL;
        if ($value1IsNull && $value2IsNull) {
            $valuasAreTheSame = TRUE;
        } else if (!$value1IsNull && !$value2IsNull) {
            if (is_float($value1) && is_float($value2)) {
                $valuasAreTheSame = abs($value1 - $value2) < PHP_FLOAT_EPSILON;
                
            } else if (
                (is_scalar($value1) && is_scalar($value2)) ||
                (is_array($value1) && is_array($value2)) ||
                ($value1 instanceof \stdClass && $value2 instanceof \stdClass)
            ) {
                $valuasAreTheSame = $value1 === $value2;
                
            } else if ($value1 instanceof \DateTimeInterface && $value2 instanceof \DateTimeInterface) {
                $valuasAreTheSame = $value1 == $value2;
                
            } else if ($value1 instanceof \DateInterval && $value2 instanceof \DateInterval) {
                $valuasAreTheSame = abs(
                    static::convertIntervalToFloat($value1) - 
                    static::convertIntervalToFloat($value2)
                ) < PHP_FLOAT_EPSILON;

            } else if ($value1 instanceof \DateTimeZone && $value2 instanceof \DateTimeZone) {
                $now = new \DateTime('now');
                $valuasAreTheSame = $value1->getOffset($now) === $value2->getOffset($now);

            } else if ($value1 instanceof \DatePeriod && $value2 instanceof \DatePeriod) {
                $valuasAreTheSame = (
                    $value1->getStartDate() == $value2->getStartDate() && 
                    $value1->getEndDate() == $value2->getEndDate() && 
                    abs(
                        static::convertIntervalToFloat($value1->getDateInterval()) - 
                        static::convertIntervalToFloat($value2->getDateInterval())
                    ) < PHP_FLOAT_EPSILON
                );

            } else if (is_resource($value1) && is_resource($value2)) {
                $valuasAreTheSame = intval($value1) == intval($value2);

            } else {
                // compare if object instances are the same (do not process any reflection comparison):
                $valuasAreTheSame = $value1 === $value2;

            }
        }
        return $valuasAreTheSame;
    }
}