<?php

namespace App\Services;

class NavbarService
{
    /**
     * Build a hierarchical tree of nav items grouped by parent_id.
     *
     * @param array $items
     * @return array
     */
    public function buildTree(array $items): array
    {
        $normalized = array_map([$this, 'normalizeItem'], $items);
        $grouped = [];

        foreach ($normalized as $item) {
            $parentId = $this->castParentId($item['parent_id'] ?? null);
            $grouped[$parentId][] = $item;
        }

        $buildLevel = function ($parentId) use (&$grouped, &$buildLevel) {
            if (!isset($grouped[$parentId])) {
                return [];
            }

            $children = $grouped[$parentId];
            usort($children, fn ($a, $b) => ($a['order'] ?? 0) <=> ($b['order'] ?? 0));

            return array_map(function ($child) use ($buildLevel) {
                $child['children'] = $buildLevel($child['id']);
                return $child;
            }, $children);
        };

        return $buildLevel(null);
    }

    private function normalizeItem($item): array
    {
        if (is_object($item)) {
            $item = (array) $item;
        }

        return [
            'id'        => (int) ($item['id'] ?? 0),
            'label'     => (string) ($item['label'] ?? ''),
            'url'       => $item['url'] ?? '',
            'icon'      => $item['icon'] ?? $item['icon_class'] ?? null,
            'parent_id' => $item['parent_id'] ?? $item['menu_parent_id'] ?? null,
            'order'     => (int) ($item['order'] ?? $item['sort_order'] ?? 0),
            'is_enabled'=> (bool) ($item['is_enabled'] ?? true),
        ];
    }

    private function castParentId($value): ?int
    {
        if ($value === null || $value === '') {
            return null;
        }

        return (int) $value;
    }

    /**
     * Clear navigation cache (placeholder for future caching implementation)
     */
    public function clearCache(): void
    {
        // TODO: Implement cache clearing if caching is added
        // For now, this is a no-op to maintain compatibility
    }
}