<?php

namespace App\Http\Controllers\API;

use App\Http\Controllers\Controller;
use App\Models\LlmMessage;
use App\Models\LlmSession;
use App\Services\LLM\DeepSeekService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Http\Response;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Str;
use Symfony\Component\HttpFoundation\StreamedResponse;

class DeepSeekChatController extends Controller
{
    public function getLlmList(): JsonResponse
    {
        $list = config('llm');
        $llmList = [];
        foreach ($list as $key => $item) {
            if (!isset($item['enabled']) || !$item['enabled']) {
                continue;
            }
            $llmList[] = [
                'name' => $item['name'],
                'model' => $item['model'],
            ];
        }

        return $this->success(['data' => $llmList]);
    }

    // 重命名
    public function renameSession(Request $request, $sessionId): JsonResponse
    {
        $userId = Auth::id();

        $title = $request->input('title');

        if (!$title) {
            return $this->badRequest('会话标题不能为空');
        }

        $session = LlmSession::query()
            ->where('session_id', $sessionId)
            ->where('user_id', $userId)
            ->first();

        if (!$session) {
            return $this->badRequest('会话不存在或无权访问');
        }

        $session->update([
            'title' => $title,
        ]);
        return $this->success(['data' => $session]);
    }

    // 删除接口
    public function deleteSession(Request $request, $sessionId)
    {
        $userId = Auth::id();

        $session = LlmSession::query()
            ->where('session_id', $sessionId)
            ->where('user_id', $userId)
            ->first();

        if (!$session) {
            return $this->badRequest('会话不存在或无权访问');
        }

        $session->delete();
        $session->messages()->delete();
    }

    /**
     * 添加会话
     *
     * @param Request $request
     * @return JsonResponse
     */
    public function addSession(Request $request): JsonResponse
    {
        $userId = Auth::id();
        if (!$request->input('title')) {
            return $this->badRequest('会话标题不能为空');
        }
        $list = config('llm');
        $modelMap = array_column($list, null, 'model');
        $llm = $modelMap[$request->input('model')] ?? null;
        if (!$llm || !$llm['enabled']) {
            return $this->badRequest('LLM服务未启用或未配置');
        }
        $session = LlmSession::create([
            'session_id' => Str::uuid(),
            'user_id' => $userId,
            'title' => $request->input('title', ''),
            'model' => $llm['model'],
        ]);

        return $this->success(['data' => $session]);
    }
    /**
     * 获取会话列表
     *
     * @param Request $request
     * @return JsonResponse
     */
    public function getSessionList(Request $request): JsonResponse
    {
        $userId = Auth::id();

        $sessions = LlmSession::where('user_id', $userId)
            ->where('updated_at', '>', now()->subDays(30))
            ->orderBy('updated_at', 'desc')->get();

        return $this->success(['data' => $sessions]);
    }

/**
     * 获取对话详情
     *
     * @param Request $request
     * @param int $sessionId
     * @return JsonResponse
     */
    public function getSessionDetail(Request $request, $sessionId): JsonResponse
    {
        $userId = Auth::id();

        $session = LlmSession::where('id', $sessionId)
            ->where('user_id', $userId)
            ->first();

        if (!$session) {
            return $this->error('会话不存在或无权访问', 404);
        }

        // 获取会话详情，包括消息历史
        $sessionData = [
            'session' => $session->toArray(),
            'messages' => $session->messages ?? []
        ];

        return $this->success(['data' => $sessionData]);
    }

    public function handleStream(Request $request): StreamedResponse
    {
        // 一个session进行多轮对话
        $sessionId = $request->input("session_id");
        $list = config('llm');
        $modelMap = array_column($list, null, 'model');
        $llm = $modelMap[$request->input('model')] ?? null;

        // 获取该session的历史对话记录
        $history = [];
        if ($sessionId) {
            // 获取该session的历史对话记录
            $session = LlmSession::query()->where('session_id', $sessionId)->firstOrFail();
            $history = $session->messages->map(function ($item) {
                return [
                    'role' => $item['role'],
                    'content' => $item['content'],
                ];
            });
        }

        return new StreamedResponse(function () use ($llm, $request, $history) {
            // 1. 设置SSE头
            header('Content-Type: text/event-stream');
            header('Cache-Control: no-cache');
            header('Connection: keep-alive');
            header('X-Accel-Buffering: no');
            header('Transfer-Encoding: chunked');
            if (!$llm) {
                return [
                    'role' => 'assistant',
                    'content' => '服务器错误，请稍后再试~',
                ];
            }
            // 2. 获取请求参数
            $prompt = $request->input('prompt', '');
            // 追加该会话上下文
            $message = array_merge($history ? $history->toArray() : [], [
                ['role' => 'user', 'content' => $prompt],
            ]);
            DeepSeekService::streamedResponseChat($llm, $message, $request->input("session_id"));
        }, 200, [
            'Content-Type' => 'text/event-stream',
        ]);
    }


}