<?php

declare(strict_types=1);

namespace App\Http\Controllers\Api\Admin;

use App\Http\Controllers\Controller;
use App\Models\LlmProvider;
use App\Services\LogService;
use Illuminate\Database\Eloquent\ModelNotFoundException;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Log;
use Illuminate\Validation\ValidationException;

class LlmProviderController extends Controller
{
    public function __construct(
        private readonly LogService $logService
    ) {}

    /**
     * Get LLM provider list
     *
     * @param Request $request
     * @return JsonResponse
     *
     * Query parameters:
     * - page: int (optional) - Page number
     * - per_page: int (optional) - Items per page
     *
     * Success response:
     * {
     *   "data": [
     *     {
     *       "id": 1001,
     *       "name": "OpenAI",
     *       "service_name": "openai",
     *       "api_url": "https://api.openai.com/v1/chat/completions",
     *       "created_at": "2023-10-01T14:00:00Z"
     *     }
     *   ],
     *   "meta": {
     *     "current_page": 1,
     *     "per_page": 15,
     *     "total": 50,
     *     "total_pages": 4
     *   }
     * }
     */
    public function index(Request $request): JsonResponse
    {
        try {
            $perPage = $request->input('per_page', 15);
            $perPage = min(max($perPage, 1), 100); // 限制每页数量在 1-100 之间

            $providers = LlmProvider::orderBy('created_at', 'desc')
                ->paginate($perPage);

            return response()->json([
                'data' => $providers->items(),
                'meta' => [
                    'current_page' => $providers->currentPage(),
                    'per_page' => $providers->perPage(),
                    'total' => $providers->total(),
                    'total_pages' => $providers->lastPage(),
                ],
            ]);

        } catch (\Exception $e) {
            Log::error('Error fetching LLM providers', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
            ]);

            return response()->json([
                'error' => 'server_error',
                'message' => '服务器内部错误。',
            ], 500);
        }
    }

    /**
     * Create new LLM provider
     *
     * @param Request $request
     * @return JsonResponse
     *
     * Request body:
     * {
     *   "name": "string",
     *   "service_name": "string",
     *   "api_url": "string",
     *   "api_token": "string"
     * }
     *
     * Success response (201):
     * {
     *   "id": 1001,
     *   "name": "OpenAI",
     *   "service_name": "openai",
     *   "api_url": "https://api.openai.com/v1/chat/completions",
     *   "created_at": "2023-10-01T14:00:00Z"
     * }
     *
     * Error response (422):
     * {
     *   "error": "validation_error",
     *   "message": "请求参数验证失败。",
     *   "errors": {
     *     "name": ["提供商名称已存在。"],
     *     "api_url": ["API URL 格式不正确。"]
     *   }
     * }
     */
    public function store(Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'name' => [
                    'required',
                    'string',
                    'max:100',
                    'unique:llm_providers',
                    'regex:/^[\w\-\s]+$/u', // 只允许字母、数字、下划线、横线和空格
                ],
                'service_name' => [
                    'required',
                    'string',
                    'max:100',
                    'regex:/^[\w\-]+$/u', // 只允许字母、数字、下划线和横线
                ],
                'api_url' => [
                    'required',
                    'string',
                    'max:255',
                    'url',
                    'starts_with:https', // 强制使用 HTTPS
                ],
                'api_token' => 'required|string|max:255',
            ], [
                'name.regex' => '提供商名称只能包含字母、数字、下划线、横线和空��。',
                'service_name.regex' => '服务名称只能包含字母、数字、下划线和横线。',
                'api_url.starts_with' => 'API URL 必须使用 HTTPS 协议。',
            ]);

            $provider = LlmProvider::create($validated);

            $this->logService->logOperation(
                'admin',
                $request->admin->id,
                "Created LLM provider: {$provider->name}"
            );

            return response()->json($provider, 201);

        } catch (ValidationException $e) {
            return response()->json([
                'error' => 'validation_error',
                'message' => '请求参数验证失败。',
                'errors' => $e->errors(),
            ], 422);
        } catch (\Exception $e) {
            Log::error('Error creating LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
            ]);

            return response()->json([
                'error' => 'server_error',
                'message' => '服务器内部错误。',
            ], 500);
        }
    }

    /**
     * Update LLM provider
     *
     * @param Request $request
     * @param int $id
     * @return JsonResponse
     *
     * Request body:
     * {
     *   "name": "string",
     *   "service_name": "string",
     *   "api_url": "string",
     *   "api_token": "string"
     * }
     *
     * Success response:
     * {
     *   "id": 1001,
     *   "name": "OpenAI Updated",
     *   "service_name": "openai",
     *   "api_url": "https://api.openai.com/v1/chat/completions",
     *   "updated_at": "2023-10-02T14:00:00Z"
     * }
     */
    public function update(Request $request, int $id): JsonResponse
    {
        try {
            $provider = LlmProvider::findOrFail($id);

            $validated = $request->validate([
                'name' => [
                    'required',
                    'string',
                    'max:100',
                    "unique:llm_providers,name,{$id}",
                    'regex:/^[\w\-\s]+$/u', // 只允许字母、数字、下划线、横线和空格
                ],
                'service_name' => [
                    'required',
                    'string',
                    'max:100',
                    'regex:/^[\w\-]+$/u', // 只允许字母、数字、下划线和横线
                ],
                'api_url' => [
                    'required',
                    'string',
                    'max:255',
                    'url',
                    'starts_with:https', // 强制使用 HTTPS
                ],
                'api_token' => 'required|string|max:255',
            ], [
                'name.regex' => '提供商名称只能包含字母、数字、下划线、横线和空格。',
                'service_name.regex' => '服务名称只能包含字母、数字、下划线和横线。',
                'api_url.starts_with' => 'API URL 必须使用 HTTPS 协议。',
            ]);

            $provider->update($validated);

            $this->logService->logOperation(
                'admin',
                $request->admin->id,
                "Updated LLM provider: {$provider->name}"
            );

            return response()->json($provider);

        } catch (ValidationException $e) {
            return response()->json([
                'error' => 'validation_error',
                'message' => '请求参数验证失败。',
                'errors' => $e->errors(),
            ], 422);
        } catch (ModelNotFoundException $e) {
            return response()->json([
                'error' => 'not_found',
                'message' => 'LLM 提供商不存在。',
            ], 404);
        } catch (\Exception $e) {
            Log::error('Error updating LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
            ]);

            return response()->json([
                'error' => 'server_error',
                'message' => '服务器内部错误。',
            ], 500);
        }
    }

    /**
     * Delete LLM provider
     *
     * @param Request $request
     * @param int $id
     * @return JsonResponse
     *
     * Success response:
     * {
     *   "message": "提供商已删除。"
     * }
     */
    public function destroy(Request $request, int $id): JsonResponse
    {
        try {
            $provider = LlmProvider::findOrFail($id);

            // 检查是否有客户正在使用该提供商
            if ($provider->clients()->exists()) {
                return response()->json([
                    'error' => 'provider_in_use',
                    'message' => '该提供商正在被客户使用，无法删除。',
                ], 422);
            }

            $providerName = $provider->name;
            $provider->delete();

            $this->logService->logOperation(
                'admin',
                $request->admin->id,
                "Deleted LLM provider: {$providerName}"
            );

            return response()->json([
                'message' => '提供商已删除。',
            ]);

        } catch (ModelNotFoundException $e) {
            return response()->json([
                'error' => 'not_found',
                'message' => 'LLM 提供商不存在。',
            ], 404);
        } catch (\Exception $e) {
            Log::error('Error deleting LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
                'provider_id' => $id,
            ]);

            return response()->json([
                'error' => 'server_error',
                'message' => '服务器内部错误。',
            ], 500);
        }
    }
}