DAS27/php-project-lvl2

<?php

namespace Differ\Formatters\Plain;

use function Funct\Collection\flattenAll;

function renderPlainDiff($tree)
{
    $iter = function ($node, $ancestry = '') use (&$iter) {
        return array_map(function ($item) use ($iter, $ancestry) {
            ['key' => $key, 'type' => $type, 'oldValue' => $oldValue, 'newValue' => $newValue] = $item;
            $propertyName = "{$ancestry}{$key}";
            $newValue = stringify($newValue);
            $oldValue = stringify($oldValue);
            switch ($type) {
                case 'changed':
                    return "Property '{$propertyName}' was changed. From '{$oldValue}' to '{$newValue}'";
                case 'deleted':
                    return "Property '{$propertyName}' was removed";
                case 'added':
                    return "Property '{$propertyName}' was added with value: '{$newValue}'";
                case 'unchanged':
                    return [];
                case 'nested':
                    return $iter($item['children'], "{$ancestry}{$key}.");
                default:
                    throw new \Exception("Undefined type: {$type}");
            }
        }, $node);
    };

    $flattened = flattenAll($iter($tree));
    return implode("\n", $flattened);
}

function stringify($value)
{
    return is_object($value) || is_array($value) ? "complex value" : $value;
}