<?php

namespace App\Services;

use App\Exceptions\BusinessException;
use App\Helpers\ResponseEnum;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;

/**
 * 基础服务类
 */
abstract class BaseService
{
    /**
     * 模型实例
     */
    protected Model $model;

    /**
     * 模型类名
     */
    protected string $modelClass;

    public function __construct()
    {
        if (isset($this->modelClass)) {
            $this->model = new $this->modelClass();
        }
    }

    /**
     * 创建记录
     */
    public function create(array $data): Model
    {
        DB::beginTransaction();

        try {
            // 验证唯一性
            $this->validateUnique($data);

            // 过滤字段
            $filteredData = $this->filterFields($data);

            // 创建记录（BaseModel会自动设置系统字段）
            $model = $this->modelClass::create($filteredData);

            DB::commit();
            return $model;

        } catch (BusinessException $e) {
            DB::rollBack();
            throw $e;
        } catch (\Exception $e) {
            DB::rollBack();
            throw new BusinessException(ResponseEnum::DATA_INSERT_ERROR, $e->getMessage());
        }
    }

    /**
     * 更新记录
     */
    public function update(int $id, array $data): Model
    {
        DB::beginTransaction();

        try {
            $model = $this->findById($id);

            // 验证租户权限
            if (!$model->validateTenantAccess()) {
                throw new BusinessException(ResponseEnum::CLIENT_HTTP_UNAUTHORIZED, '无权限访问该数据');
            }

            // 验证唯一性（排除当前记录）
            $this->validateUnique($data, $id);

            // 过滤字段
            $filteredData = $this->filterFields($data);

            // 更新记录（BaseModel会自动设置更新字段）
            $model->update($filteredData);

            DB::commit();
            return $model;

        } catch (BusinessException $e) {
            DB::rollBack();
            throw $e;
        } catch (\Exception $e) {
            DB::rollBack();
            throw new BusinessException(ResponseEnum::DATA_UPDATE_ERROR, $e->getMessage());
        }
    }

    /**
     * 删除记录
     */
    public function delete(int $id): bool
    {
        DB::beginTransaction();

        try {
            $model = $this->findById($id);

            // 验证租户权限
            if (!$model->validateTenantAccess()) {
                throw new BusinessException(ResponseEnum::CLIENT_HTTP_UNAUTHORIZED, '无权限访问该数据');
            }

            $result = $model->delete();

            DB::commit();
            return $result;

        } catch (BusinessException $e) {
            DB::rollBack();
            throw $e;
        } catch (\Exception $e) {
            DB::rollBack();
            throw new BusinessException(ResponseEnum::DATA_DELETE_ERROR, $e->getMessage());
        }
    }

    /**
     * 批量删除记录
     */
    public function batchDelete(array $ids): bool
    {
        DB::beginTransaction();

        try {
            if (empty($ids)) {
                throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, 'ID列表不能为空');
            }

            // 验证所有记录的租户权限
            $models = $this->modelClass::whereIn('id', $ids)->get();

            foreach ($models as $model) {
                if (!$model->validateTenantAccess()) {
                    throw new BusinessException(ResponseEnum::CLIENT_HTTP_UNAUTHORIZED, '无权限访问部分数据');
                }
            }

            $deleteCount = $this->modelClass::whereIn('id', $ids)->delete();

            if ($deleteCount === 0) {
                throw new BusinessException(ResponseEnum::DATA_NOT_FOUND_ERROR);
            }

            DB::commit();
            return true;

        } catch (BusinessException $e) {
            DB::rollBack();
            throw $e;
        } catch (\Exception $e) {
            DB::rollBack();
            throw new BusinessException(ResponseEnum::DATA_DELETE_ERROR, $e->getMessage());
        }
    }

    /**
     * 获取记录详情
     */
    public function detail(int $id): Model
    {
        $model = $this->findById($id);

        // 验证租户权限
        if (!$model->validateTenantAccess()) {
            throw new BusinessException(ResponseEnum::CLIENT_HTTP_UNAUTHORIZED, '无权限访问该数据');
        }

        return $model;
    }

    /**
     * 获取记录列表（基础版）
     */
    public function list(array $params): LengthAwarePaginator
    {
        $page = (int)($params['page'] ?? 1);
        $pageSize = (int)($params['page_size'] ?? 15);

        // 使用模型的全局作用域自动过滤租户数据
        $query = $this->modelClass::query();

        // 子类可以重写此方法来添加特定的搜索条件
        $this->applySearchConditions($query, $params);

        // 添加排序
        $query->ordered();

        return $query->paginate($pageSize, ['*'], 'page', $page);
    }

    /**
     * 应用搜索条件（子类重写此方法）
     */
    protected function applySearchConditions($query, array $params): void
    {
        // 默认不添加任何搜索条件，子类可以重写
    }

    /**
     * 根据ID查找记录
     */
    protected function findById(int $id): Model
    {
        // 使用模型的全局作用域自动过滤租户数据
        $model = $this->modelClass::find($id);

        if (!$model) {
            throw new BusinessException(ResponseEnum::DATA_NOT_FOUND_ERROR);
        }

        return $model;
    }

    /**
     * 验证唯一性（子类重写此方法）
     */
    protected function validateUnique(array $data, ?int $excludeId = null): void
    {
        // 默认不验证唯一性，子类可以重写
    }

    /**
     * 过滤字段
     */
    protected function filterFields(array $data): array
    {
        $fillable = $this->model->getFillable();

        return array_filter(
            array_intersect_key($data, array_flip($fillable)),
            function ($value) {
                return $value !== null && $value !== '';
            }
        );
    }

    /**
     * 获取当前租户ID
     */
    protected function getCurrentTenantId(): ?int
    {
        $user = auth('admin')->user();
        return $user ? $user->tenant_id : null;
    }

    /**
     * 验证租户权限
     */
    protected function validateTenantAccess(?int $tenantId): bool
    {
        $currentTenantId = $this->getCurrentTenantId();

        if ($currentTenantId === null) {
            return false;
        }

        return $tenantId == $currentTenantId;
    }
}