<?php

declare(strict_types=1);

namespace App\Http\Controllers\Api\Admin;

use App\Constants\ErrorCode;
use App\Http\Controllers\Controller;
use App\Models\Admin;
use App\Models\LlmProvider;
use App\Services\LogService;
use App\Traits\ApiResponse;
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
{
    use ApiResponse;

    private Admin $admin;

    public function __construct(
        private readonly LogService $logService,
        Request $request
    ) {
        $this->admin = $request->admin;
    }

    /**
     * 獲取 LLM 提供商列表
     */
    public function index(): JsonResponse
    {
        try {
            $providers = LlmProvider::select([
                'id',
                'name',
                'service_name',
                'api_url',
                'status',
                'created_at',
            ])->get();

            return $this->success($providers);

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

            return $this->error(
                ErrorCode::SERVER_ERROR,
                ErrorCode::getMessage(ErrorCode::SERVER_ERROR)
            );
        }
    }

    /**
     * 新增 LLM 提供商
     */
    public function store(Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'name' => [
                    'required',
                    'string',
                    'max:100',
                    'unique:llm_providers',
                ],
                'service_name' => [
                    'required',
                    'string',
                    'max:100',
                ],
                'api_url' => [
                    'required',
                    'string',
                    'url',
                    'max:255',
                ],
                'api_token' => [
                    'required',
                    'string',
                    'max:255',
                ],
            ]);

            $validated['status'] = LlmProvider::STATUS_ACTIVE;
            $provider = LlmProvider::create($validated);

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

            return $this->created([
                'id' => $provider->id,
                'name' => $provider->name,
                'service_name' => $provider->service_name,
                'api_url' => $provider->api_url,
                'api_token' => $provider->api_token,
                'created_at' => $provider->created_at->toIso8601String(),
            ]);

        } catch (ValidationException $e) {
            return $this->error(
                ErrorCode::VALIDATION_ERROR,
                ErrorCode::getMessage(ErrorCode::VALIDATION_ERROR),
                $e->errors()
            );
        } catch (\Exception $e) {
            Log::error('Error creating LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
                'request_data' => $request->except(['api_token']),
            ]);

            return $this->error(
                ErrorCode::SERVER_ERROR,
                ErrorCode::getMessage(ErrorCode::SERVER_ERROR)
            );
        }
    }

    /**
     * 修改 LLM 提供商
     */
    public function update(Request $request, int $id): JsonResponse
    {
        try {
            $provider = LlmProvider::findOrFail($id);

            if (!$this->admin->canManageLlmProvider($provider->id)) {
                return $this->error(
                    ErrorCode::FORBIDDEN,
                    '您無權管理該 LLM 提供商。'
                );
            }

            $validated = $request->validate([
                'name' => [
                    'required',
                    'string',
                    'max:100',
                    "unique:llm_providers,name,{$id}",
                ],
                'service_name' => [
                    'required',
                    'string',
                    'max:100',
                ],
                'api_url' => [
                    'required',
                    'string',
                    'url',
                    'max:255',
                ],
                'api_token' => [
                    'required',
                    'string',
                    'max:255',
                ],
                'status' => [
                    'required',
                    'string',
                    'in:active,inactive',
                ],
            ]);

            // 如果要停用提供商，檢查是否有客戶在使用
            if ($validated['status'] === LlmProvider::STATUS_INACTIVE &&
                $provider->status === LlmProvider::STATUS_ACTIVE) {
                if ($provider->clients()->exists()) {
                    return $this->error(
                        ErrorCode::RESOURCE_IN_USE,
                        '該提供商正在被客戶使用，無法停用。'
                    );
                }
            }

            $provider->update($validated);

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

            return $this->success([
                'id' => $provider->id,
                'name' => $provider->name,
                'service_name' => $provider->service_name,
                'api_url' => $provider->api_url,
                'api_token' => $provider->api_token,
                'updated_at' => $provider->updated_at->toIso8601String(),
            ]);

        } catch (ValidationException $e) {
            return $this->error(
                ErrorCode::VALIDATION_ERROR,
                ErrorCode::getMessage(ErrorCode::VALIDATION_ERROR),
                $e->errors()
            );
        } catch (ModelNotFoundException $e) {
            return $this->error(
                ErrorCode::RESOURCE_NOT_FOUND,
                ErrorCode::getMessage(ErrorCode::RESOURCE_NOT_FOUND)
            );
        } catch (\Exception $e) {
            Log::error('Error updating LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
                'provider_id' => $id,
                'request_data' => $request->except(['api_token']),
            ]);

            return $this->error(
                ErrorCode::SERVER_ERROR,
                ErrorCode::getMessage(ErrorCode::SERVER_ERROR)
            );
        }
    }

    /**
     * 刪除 LLM 提供商
     */
    public function destroy(int $id): JsonResponse
    {
        try {
            $provider = LlmProvider::findOrFail($id);

            if (!$this->admin->canManageLlmProvider($provider->id)) {
                return $this->error(
                    ErrorCode::FORBIDDEN,
                    '您無權管理該 LLM 提供商。'
                );
            }

            // 檢查是否有客戶在使用
            if ($provider->clients()->exists()) {
                return $this->error(
                    ErrorCode::RESOURCE_IN_USE,
                    '該提供商正在被客戶使用，無法刪除。'
                );
            }

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

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

            return $this->success(null, 'LLM 提供商已刪除。');

        } catch (ModelNotFoundException $e) {
            return $this->error(
                ErrorCode::RESOURCE_NOT_FOUND,
                ErrorCode::getMessage(ErrorCode::RESOURCE_NOT_FOUND)
            );
        } catch (\Exception $e) {
            Log::error('Error deleting LLM provider', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
                'provider_id' => $id,
            ]);

            return $this->error(
                ErrorCode::SERVER_ERROR,
                ErrorCode::getMessage(ErrorCode::SERVER_ERROR)
            );
        }
    }
}