<?php

namespace App\Utility\Utils;

// src: https://www.php.net/manual/en/function.array-diff.php#91756
function array_diff_recursive($arr1, $arr2)
{
    $outputDiff = [];

    foreach ($arr1 as $key => $value) {
        //if the key exists in the second array, recursively call this function 
        //if it is an array, otherwise check if the value is in arr2
        if (array_key_exists($key, $arr2)) {
            if (is_array($value)) {
                $recursiveDiff = array_diff_recursive($value, $arr2[$key]);

                if (count($recursiveDiff)) {
                    $outputDiff[$key] = $recursiveDiff;
                }
            } else if (!in_array($value, $arr2)) {
                $outputDiff[$key] = $value;
            }
        }
        //if the key is not in the second array, check if the value is in 
        //the second array (this is a quirk of how array_diff works)
        else if (!in_array($value, $arr2)) {
            $outputDiff[$key] = $value;
        }
    }

    return $outputDiff;
}