<?php

declare (strict_types = 1);

namespace addon\download\model;

use ywxapp\model\BaseModel;

class Category extends BaseModel
{
    protected function getOptions(): array
    {
        return [
            'strict'      => false,
            'name'        => 'download_category',
            'autoRelation' => [],
            'createTime'  => 'create_at',
            'updateTime'  => 'update_at',
            'dateFormat'  => 'Y-m-d H:i:s',
        ];
    }

    /**
     * 子分类（pid 指向自身）
     */
    public function children()
    {
        return $this->hasMany(self::class, 'pid', 'id')
            ->where('status', 1)
            ->order('sort', 'desc');
    }

    /**
     * 分类下的资源
     */
    public function resources()
    {
        return $this->hasMany(Resource::class, 'cid', 'id')
            ->where('status', 1)
            ->where('is_audit', 1);
    }

    /**
     * 平铺分类列表转带前缀的下拉选项（供新增/编辑表单的上级分类 select 使用）
     * 直接复用父类 BaseModel::cateTree($cate, $name='title', $lefthtml='|— ', $pid=0, $level=0)，
     * 返回的 title 自带层级前缀，无需在子类重复声明（会与父类签名冲突 fatal error）。
     */

    /**
     * 将平铺分类列表转换为嵌套树（供 layui.treeTable 使用）
     * 返回形如 [['id'=>..,'children'=>[...]], ...]
     */
    public static function toNestedTree(array $list): array
    {
        $map = [];
        foreach ($list as &$item) {
            $item['children'] = [];
            $map[$item['id']]  = &$item;
        }
        unset($item);
        $tree = [];
        foreach ($list as &$item) {
            if (!empty($item['pid']) && isset($map[$item['pid']])) {
                $map[$item['pid']]['children'][] = &$item;
            } else {
                $tree[] = &$item;
            }
        }
        unset($item);
        // 清理空的 children，保持返回结构干净
        return self::cleanEmptyChildren($tree);
    }

    protected static function cleanEmptyChildren(array $tree): array
    {
        foreach ($tree as &$node) {
            if (!empty($node['children'])) {
                $node['children'] = self::cleanEmptyChildren($node['children']);
            } else {
                unset($node['children']);
            }
        }
        return $tree;
    }

    /**
     * 删除前保护：存在子分类或资源时禁止删除
     */
    public static function onBeforeDelete($model)
    {
        $childCount = self::where('pid', $model->id)->count();
        if ($childCount > 0) {
            throw new \think\Exception('该分类下还存在 ' . $childCount . ' 个子分类，请先处理子分类');
        }
        $resCount = \addon\download\model\Resource::where('cid', $model->id)->count();
        if ($resCount > 0) {
            throw new \think\Exception('该分类下还存在 ' . $resCount . ' 个资源，请先移走或删除这些资源');
        }
    }
}