jude-cehua/app.py

import os
import json
import uuid
import time
import logging
from typing import Dict, Any, Generator, Optional, List
from flask_cors import CORS

import requests
from flask import Flask, request, jsonify, render_template, session, Response, stream_with_context, redirect
from http import HTTPStatus
from dotenv import load_dotenv, find_dotenv
from dashscope import Application
from datetime import datetime

# 先加载环境变量，确保后续模块读取到 .env（支持不同工作目录）
load_dotenv(find_dotenv(), override=False)

# 导入认证模块
from auth_middleware import init_auth
from auth_routes import auth_bp

# 导入配置和工具
from config import config
from utils import (
    sanitize_input, validate_user_id, rate_limit, 
    truncate_conversation_history, log_request_info, get_beijing_time,
    generate_session_id
)

# 导入数据库模型
from models import init_database, db, User, Conversation, Message, get_or_create_user

# 配置日志
logging.basicConfig(
    level=getattr(logging, config.log_level),
    format=config.log_format
)
logger = logging.getLogger(__name__)

# 创建Flask应用
app = Flask(__name__)
CORS(app)  # 启用CORS支持

# 配置session
app.secret_key = config.secret_key
app.config['PERMANENT_SESSION_LIFETIME'] = 7 * 24 * 60 * 60  # 7天
app.config['SESSION_COOKIE_SECURE'] = False  # 开发环境设为False
app.config['SESSION_COOKIE_HTTPONLY'] = True
app.config['SESSION_COOKIE_SAMESITE'] = 'Lax'

# 配置数据库
app.config['SQLALCHEMY_DATABASE_URI'] = config.get_database_url()
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_ENGINE_OPTIONS'] = {
    'pool_pre_ping': True,
    'pool_recycle': 300,
    'pool_timeout': 20,
    'max_overflow': 0
}

# 初始化数据库
try:
    init_database(app)
except Exception as e:
    logger.error(f"数据库初始化失败: {str(e)}", exc_info=True)
    raise

# 初始化认证中间件
auth_middleware = init_auth(app)
app.auth_middleware = auth_middleware

# 注册认证蓝图
app.register_blueprint(auth_bp)

# 存储用户当前对话ID的字典（保留用于兼容性）
user_current_conversations: Dict[str, int] = {}


@app.after_request
def add_cache_control_headers(response):
    """
    防止首页HTML被中间层或浏览器长期缓存，避免出现"旧HTML引用新/旧静态资源"导致白屏。
    静态资源保持默认缓存策略，仅对HTML页面禁缓存。
    """
    content_type = (response.content_type or "").lower()
    if "text/html" in content_type:
        response.headers["Cache-Control"] = "no-store, no-cache, must-revalidate, max-age=0"
        response.headers["Pragma"] = "no-cache"
        response.headers["Expires"] = "0"
    return response

def save_message_to_database(user_id: int, conversation_id: int, role: str, content: str, 
                            thinking_content: str = None, message_order: int = 1) -> Message:
    """保存消息到数据库"""
    try:
        message = Message(
            conversation_id=conversation_id,
            role=role,
            content=content,
            thinking_content=thinking_content,
            content_type='text',
            message_order=message_order
        )
        
        db.session.add(message)
        
        # 更新对话的消息计数和最后消息时间
        conversation = Conversation.query.get(conversation_id)
        if conversation:
            conversation.message_count += 1
            conversation.last_message_at = get_beijing_time()
            conversation.updated_at = get_beijing_time()
        
        # 一次性提交所有更改
        db.session.commit()
        
        return message
        
    except Exception as e:
        db.session.rollback()
        logger.error(f"保存消息到数据库时发生错误: {str(e)}", exc_info=True)
        raise

def get_or_create_conversation(user_id: int, title: str = None, conversation_id: int = None, force_new: bool = False) -> Conversation:
    """获取或创建对话"""
    try:
        # 如果强制创建新对话，直接创建
        if force_new:
            if not title:
                title = f"对话 {get_beijing_time().strftime('%Y-%m-%d %H:%M')}"
            
            # 生成新的session_id
            session_id = generate_session_id(user_id)
            
            conversation = Conversation(
                user_id=user_id,
                title=title,
                conversation_type='chat',
                session_id=session_id,
                message_count=0
            )
            
            db.session.add(conversation)
            db.session.commit()
            
            # 更新用户的当前对话ID
            user_current_conversations[str(user_id)] = conversation.conversation_id
            
            
            return conversation
        
        # 如果指定了conversation_id，验证并返回该对话
        if conversation_id:
            conversation = Conversation.query.filter_by(
                conversation_id=conversation_id,
                user_id=user_id,
                is_deleted=False
            ).first()
            if conversation:
                # 如果对话没有session_id，生成一个
                if not conversation.session_id:
                    conversation.session_id = generate_session_id(user_id, conversation_id)
                    db.session.commit()
                
                # 更新用户的当前对话ID
                user_current_conversations[str(user_id)] = conversation.conversation_id
                return conversation
        
        # 检查用户是否有当前对话映射
        current_conv_id = user_current_conversations.get(str(user_id))
        
        if current_conv_id:
            conversation = Conversation.query.filter_by(
                conversation_id=current_conv_id,
                user_id=user_id,
                is_deleted=False
            ).first()
            if conversation:
                # 如果对话没有session_id，生成一个
                if not conversation.session_id:
                    conversation.session_id = generate_session_id(user_id, current_conv_id)
                    db.session.commit()
                return conversation
        
        # 创建新对话
        if not title:
            title = f"对话 {get_beijing_time().strftime('%Y-%m-%d %H:%M')}"
        
        # 生成新的session_id
        session_id = generate_session_id(user_id)
        
        conversation = Conversation(
            user_id=user_id,
            title=title,
            conversation_type='chat',
            session_id=session_id,
            message_count=0
        )
        
        db.session.add(conversation)
        db.session.commit()
        
        # 更新用户的当前对话ID
        user_current_conversations[str(user_id)] = conversation.conversation_id
        
        return conversation
        
    except Exception as e:
        db.session.rollback()
        logger.error(f"获取或创建对话时发生错误: {str(e)}", exc_info=True)
        raise

def switch_to_conversation(user_id: int, conversation_id: int) -> Conversation:
    """切换到指定对话"""
    try:
        # 验证对话是否属于当前用户
        conversation = Conversation.query.filter_by(
            conversation_id=conversation_id,
            user_id=user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            raise ValueError(f"对话 {conversation_id} 不存在或无权限访问")
        
        # 如果对话没有session_id，生成一个
        if not conversation.session_id:
            conversation.session_id = generate_session_id(user_id, conversation_id)
            db.session.commit()
            
        
        # 更新用户的当前对话ID
        user_current_conversations[str(user_id)] = conversation.conversation_id
        
        
        return conversation
        
    except Exception as e:
        logger.error(f"切换对话时发生错误: {str(e)}", exc_info=True)
        raise

def generate_conversation_title(user_message: str) -> str:
    """根据用户消息生成对话标题"""
    # 取用户消息的前50个字符作为标题
    title = user_message.strip()[:50]
    if len(user_message) > 50:
        title += "..."
    return title

@app.route('/')
def index():
    """渲染聊天界面"""
    # 检查是否是登录成功跳转
    login_success = request.args.get('login_success')
    token = request.args.get('token')
    user_info_json = request.args.get('user_info')
    
    if login_success and token and user_info_json:
        # 登录成功，处理用户信息
        try:
            import urllib.parse
            import json
            user_info = json.loads(urllib.parse.unquote(user_info_json))
            
            # 保存到session
            session['auth_token'] = token
            session['user_info'] = user_info
            
            # 将用户信息传递给模板
            return render_template('index.html', user_info=user_info, jwt_token=token)
        except Exception as e:
            logger.error(f'处理登录成功参数失败: {e}')
            # 如果处理失败，重定向到登录页面
            return redirect('/login')
    else:
        # 正常访问，检查认证状态
        # 优先从session获取
        user_info = session.get('user_info', {})
        jwt_token = session.get('auth_token', '')
        
        # 如果session中没有，尝试从localStorage获取（通过JavaScript）
        if not jwt_token:
            # 返回一个页面，让JavaScript检查localStorage
            return render_template('index.html', user_info={}, jwt_token='')
        
        # 将用户信息传递给模板
        return render_template('index.html', user_info=user_info, jwt_token=jwt_token)

@app.route('/login')
def login():
    """登录页面"""
    return render_template('login.html')

@app.route('/login_error')
def login_error():
    """登录错误页面"""
    error_type = request.args.get('error', 'unknown')
    error_message = request.args.get('message', '')
    error_code = request.args.get('code', '')

    return render_template('login_error.html',
                         error_type=error_type,
                         error_message=error_message,
                         error_code=error_code)

@app.route('/api/chat', methods=['POST'])
@auth_middleware.login_required
@rate_limit(config.rate_limit_requests, config.rate_limit_window)
def chat():
    """处理聊天请求并调用阿里云百炼API (非流式响应)"""
    try:
        data = request.json or {}
        message = data.get('message', '')
        user_id = data.get('user_id', str(uuid.uuid4()))
        agent = data.get('agent') or 'kuaishou'
        conversation_id = data.get('conversation_id')  # 新增：支持指定对话ID
        session_id = data.get('session_id')  # 新增：支持指定session_id
        force_new = data.get('force_new', False)  # 新增：强制创建新对话
        
        # 输入验证
        message, error = sanitize_input(message, config.max_message_length)
        if error:
            return jsonify({
                'success': False,
                'error': error
            }), HTTPStatus.BAD_REQUEST
        
        user_id, error = validate_user_id(user_id)
        if error:
            return jsonify({
                'success': False,
                'error': error
            }), HTTPStatus.BAD_REQUEST
        
        # 从认证中间件获取用户信息
        auth_user_info = getattr(request, 'user_info', {})
        auth_user_id = auth_user_info.get('db_user_id')  # 使用数据库用户ID
        
        # 选择对应智能体 APP_ID
        chosen_app_id, appid_env_key = config.get_app_id_for_agent_with_source(agent)
        if not chosen_app_id:
            logger.error(f"未找到对应智能体APP_ID，agent={agent}")
            return jsonify({
                'success': False,
                'error': f"服务器未配置该智能体的 APP_ID: {agent}"
            }), HTTPStatus.INTERNAL_SERVER_ERROR
        
        # 记录请求信息
        log_request_info(message, user_id, 'POST')
        
        # 获取或创建对话
        conversation = get_or_create_conversation(
            auth_user_id, 
            generate_conversation_title(message),
            conversation_id,
            force_new
        )
        
        # 优先使用前端传来的session_id，否则使用对话的session_id
        api_session_id = session_id or conversation.session_id
        
        # 准备API请求参数
        headers = {
            "Authorization": f"Bearer {config.api_key}",
            "Content-Type": "application/json",
            "X-DashScope-SSE": "disable"  # 禁用流式输出
        }
        
        # 从数据库获取对话历史
        messages_query = Message.query.filter_by(
            conversation_id=conversation.conversation_id,
            is_deleted=False
        ).order_by(Message.message_order.asc()).all()
        
        # 构建多轮对话历史
        messages = []
        for msg in messages_query:
            messages.append({"role": msg.role, "content": msg.content})
        
        # 添加用户新消息到对话历史
        messages.append({"role": "user", "content": message})
        
        # 截断对话历史以控制内存使用
        messages = truncate_conversation_history(messages, config.max_conversation_history)
        
        payload = {
            "model": "application",
            "parameters": {"app_id": chosen_app_id},
            "input": {"messages": messages}  # 发送完整的对话历史
        }
        
        # 如果有会话ID，添加到请求参数中
        if api_session_id:
            payload["parameters"]["session_id"] = api_session_id
        
        # 发送API请求
        response = requests.post(
            config.api_endpoint,
            headers=headers,
            json=payload,
            timeout=60
        )
        
        # 转换为JSON
        response_json = response.json()
        
        if response.status_code != HTTPStatus.OK:
            return jsonify({
                'success': False,
                'error': f"错误: {response.status_code} - {response_json.get('message', '未知错误')}",
                'request_id': response_json.get('request_id', ''),
                'agent': agent
            }), HTTPStatus.INTERNAL_SERVER_ERROR
        
        # 解析返回结果
        output = response_json.get('output', {})
        choices = output.get('choices', [{}])
        text = choices[0].get('message', {}).get('content', '') if choices else ''
        new_session_id = output.get('session_id', '')
        thoughts_content = output.get('thoughts', [])
        
        # 更新对话的session_id（如果API返回了新的session_id且与当前不同）
        if new_session_id and new_session_id != api_session_id:
            conversation.session_id = new_session_id
            db.session.commit()
            
        elif not api_session_id and new_session_id:
            # 如果对话原本没有session_id，现在有了，更新数据库
            conversation.session_id = new_session_id
            db.session.commit()
            
        
        # 保存到数据库
        try:
            # 获取当前对话的消息数量，用于设置消息顺序
            current_message_count = Message.query.filter_by(
                conversation_id=conversation.conversation_id,
                is_deleted=False
            ).count()
            
            # 保存用户消息
            save_message_to_database(
                auth_user_id,
                conversation.conversation_id,
                'user',
                message,
                message_order=current_message_count + 1
            )
            
            # 保存AI回复
            if text:
                thinking_text = '\n'.join(thoughts_content) if thoughts_content else None
                save_message_to_database(
                    auth_user_id,
                    conversation.conversation_id,
                    'assistant',
                    text,
                    thinking_text,
                    message_order=current_message_count + 2
                )
            
            # 更新对话标题（如果是第一条消息）
            if conversation.message_count <= 2:  # 用户消息 + AI回复
                new_title = generate_conversation_title(message)
                # 检查是否是默认标题（"新对话"或"对话 时间"格式）
                is_default_title = (
                    conversation.title == "新对话" or 
                    conversation.title == f"对话 {conversation.created_at.strftime('%Y-%m-%d %H:%M')}"
                )
                if is_default_title:
                    conversation.title = new_title
                    db.session.commit()
            
        except Exception as db_error:
            logger.error(f"保存对话到数据库时发生错误: {str(db_error)}", exc_info=True)
            # 不影响主要功能，继续返回结果
        
        return jsonify({
            'success': True,
            'message': text,
            'user_id': user_id,
            'session_id': new_session_id or api_session_id,
            'thoughts': thoughts_content,
            'agent': agent,
            'conversation_id': conversation.conversation_id
        })
    
    except requests.exceptions.RequestException as e:
        logger.error(f"API请求异常: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"API请求异常: {str(e)}"
        }), HTTPStatus.SERVICE_UNAVAILABLE
    except Exception as e:
        logger.error(f"API调用错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/chat/stream', methods=['GET', 'POST'])
@auth_middleware.login_required
@rate_limit(config.rate_limit_requests, config.rate_limit_window)
def chat_stream():
    """处理聊天请求并以流式方式返回响应"""
    try:
        # 从请求中获取数据
        if request.method == 'GET':
            message = request.args.get('message', '')
            user_id = request.args.get('user_id', str(uuid.uuid4()))
            agent = request.args.get('agent') or 'kuaishou'
            conversation_id = request.args.get('conversation_id')  # 支持指定对话ID
        else:  # POST
            data = request.json or {}
            message = data.get('message', '')
            user_id = data.get('user_id', str(uuid.uuid4()))
            agent = data.get('agent') or 'kuaishou'
            conversation_id = data.get('conversation_id')  # 支持指定对话ID
            session_id = data.get('session_id')  # 支持指定session_id
            force_new = data.get('force_new', False)  # 强制创建新对话
        
        # 输入验证
        message, error = sanitize_input(message, config.max_message_length)
        if error:
            return Response(
                f"data: {json.dumps({'success': False, 'error': error, 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        user_id, error = validate_user_id(user_id)
        if error:
            return Response(
                f"data: {json.dumps({'success': False, 'error': error, 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 选择对应智能体 APP_ID
        chosen_app_id, appid_env_key = config.get_app_id_for_agent_with_source(agent)
        if not chosen_app_id:
            logger.error(f"未找到对应智能体APP_ID，agent={agent}")
            return Response(
                f"data: {json.dumps({'success': False, 'error': f'服务器未配置该智能体的 APP_ID: {agent}', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 记录请求信息
        log_request_info(message, user_id, request.method)
        
        # 从认证中间件获取用户信息
        auth_user_info = getattr(request, 'user_info', {})
        auth_user_id = auth_user_info.get('db_user_id')  # 使用数据库用户ID
        
        # 获取或创建对话
        conversation = get_or_create_conversation(
            auth_user_id, 
            generate_conversation_title(message),
            conversation_id,
            force_new
        )
        
        # 优先使用前端传来的session_id，否则使用对话的session_id
        api_session_id = session_id or conversation.session_id
        
        # 从数据库获取对话历史
        messages_query = Message.query.filter_by(
            conversation_id=conversation.conversation_id,
            is_deleted=False
        ).order_by(Message.message_order.asc()).all()
        
        # 构建多轮对话历史
        messages = []
        for msg in messages_query:
            messages.append({"role": msg.role, "content": msg.content})
        
        # 添加用户新消息到对话历史
        messages.append({"role": "user", "content": message})
        
        # 截断对话历史以控制内存使用
        messages = truncate_conversation_history(messages, config.max_conversation_history)
        
        # 立即保存用户消息到数据库（在流式响应开始前）
        try:
            # 获取当前对话的消息数量，用于设置消息顺序
            current_message_count = Message.query.filter_by(
                conversation_id=conversation.conversation_id,
                is_deleted=False
            ).count()
            
            # 立即保存用户消息
            user_message = save_message_to_database(
                auth_user_id,
                conversation.conversation_id,
                'user',
                message,
                message_order=current_message_count + 1
            )
            
            
        except Exception as db_error:
            logger.error(f"保存用户消息到数据库时发生错误: {str(db_error)}", exc_info=True)
            return Response(
                f"data: {json.dumps({'success': False, 'error': f'保存用户消息失败: {str(db_error)}', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 定义流式响应生成器
        def generate() -> Generator[str, None, None]:
            try:
                # 发送初始响应，包含用户消息ID，防止浏览器超时
                initial_data = {
                    'success': True,
                    'chunk': '',
                    'done': False,
                    'agent': agent,
                    'user_message_id': user_message.message_id if user_message else None
                }
                yield f"data: {json.dumps(initial_data)}\n\n"
                
                try:
                    # 使用DashScope SDK直接调用 - 多轮对话模式
                    params = {
                        "api_key": config.api_key,
                        "app_id": chosen_app_id,
                        "messages": messages,  # 发送完整的对话历史
                        "stream": True,
                        "incremental_output": True,
                        "has_thoughts": True
                    }
                    
                    # 使用对话的session_id
                    if api_session_id:
                        params["session_id"] = api_session_id
                    
                    response = Application.call(**params)
                    
                    new_session_id: Optional[str] = None
                    accumulated_text: str = ""
                    thoughts_content: List[str] = []
                    
                    # 处理流式响应
                    for chunk in response:
                        # 检查客户端是否断开连接
                        if request.environ.get('werkzeug.server.shutdown') or not request:
                            break
                            
                        if chunk.status_code != HTTPStatus.OK:
                            yield f"data: {json.dumps({'success': False, 'error': f'错误: {chunk.status_code} - {chunk.message}', 'request_id': chunk.request_id, 'done': True, 'agent': agent})}\n\n"
                            return
                        
                        # 处理思考过程
                        if hasattr(chunk.output, 'thoughts') and chunk.output.thoughts:
                            for it in chunk.output.thoughts:
                                if it.action_type == 'reasoning':
                                    content = str(it.thought) if not isinstance(it.thought, str) else it.thought
                                    thoughts_content.append(content)
                                    yield f"data: {json.dumps({'success': True, 'thought': content, 'done': False, 'agent': agent})}\n\n"
                        
                        # 处理回答内容
                        if hasattr(chunk.output, 'text') and chunk.output.text:
                            current_text = str(chunk.output.text)
                            accumulated_text += current_text
                            yield f"data: {json.dumps({'success': True, 'chunk': current_text, 'done': False, 'agent': agent})}\n\n"
                        
                        # 检查是否有会话ID
                        if hasattr(chunk.output, 'session_id') and chunk.output.session_id:
                            new_session_id = chunk.output.session_id
                    
                    # 处理结束
                    if new_session_id and new_session_id != api_session_id:
                        conversation.session_id = new_session_id
                        db.session.commit()
                    elif not api_session_id and new_session_id:
                        # 如果对话原本没有session_id，现在有了，更新数据库
                        conversation.session_id = new_session_id
                        db.session.commit()
                    
                    # 保存AI回复到数据库
                    try:
                        if accumulated_text:
                            thinking_text = '\n'.join(thoughts_content) if thoughts_content else None
                            ai_message = save_message_to_database(
                                auth_user_id,
                                conversation.conversation_id,
                                'assistant',
                                accumulated_text,
                                thinking_text,
                                message_order=current_message_count + 2
                            )
                            
                            # 更新对话标题（如果是第一条消息）
                            if conversation.message_count <= 2:  # 用户消息 + AI回复
                                new_title = generate_conversation_title(message)
                                # 检查是否是默认标题（"新对话"或"对话 时间"格式）
                                is_default_title = (
                                    conversation.title == "新对话" or 
                                    conversation.title == f"对话 {conversation.created_at.strftime('%Y-%m-%d %H:%M')}"
                                )
                                if is_default_title:
                                    conversation.title = new_title
                                    db.session.commit()
                            
                    except Exception as db_error:
                        logger.error(f"保存AI回复到数据库时发生错误: {str(db_error)}", exc_info=True)
                        # 不影响主要功能，继续返回结果
                    
                    # 发送完成标记
                    final_data = {
                        'success': True,
                        'done': True,
                        'thoughts': thoughts_content,
                        'agent': agent,
                        'session_id': new_session_id or api_session_id,
                        'user_id': user_id,
                        'conversation_id': conversation.conversation_id
                    }
                    
                    yield f"data: {json.dumps(final_data)}\n\n"
                    
                except Exception as e:
                    logger.error(f"DashScope SDK 调用错误: {str(e)}", exc_info=True)
                    yield f"data: {json.dumps({'success': False, 'error': f'DashScope API调用错误: {str(e)}', 'done': True, 'agent': agent})}\n\n"
            
            except Exception as e:
                logger.error(f"流式API调用错误: {str(e)}", exc_info=True)
                yield f"data: {json.dumps({'success': False, 'error': f'发生错误: {str(e)}', 'done': True, 'agent': agent})}\n\n"
        
        # 创建并返回流式响应
        response = Response(stream_with_context(generate()), content_type='text/event-stream')
        response.headers['Cache-Control'] = 'no-cache'
        response.headers['X-Accel-Buffering'] = 'no'
        return response
    
    except Exception as e:
        logger.error(f"请求处理错误: {str(e)}", exc_info=True)
        response = Response(
            f"data: {json.dumps({'success': False, 'error': f'发生错误: {str(e)}', 'done': True})}\n\n",
            content_type='text/event-stream'
        )
        response.headers['Cache-Control'] = 'no-cache'
        return response

@app.route('/api/reset', methods=['POST'])
@auth_middleware.login_required
@rate_limit(10, 60)
def reset_session():
    """重置用户会话"""
    try:
        data = request.json or {}
        user_id = data.get('user_id')
        
        if not user_id:
            return jsonify({
                'success': True,
                'message': '没有提供用户ID，但重置请求已处理'
            })
        
        # 验证用户ID格式
        user_id, error = validate_user_id(user_id)
        if error:
            return jsonify({
                'success': False,
                'error': error
            }), HTTPStatus.BAD_REQUEST
        
        # 从认证中间件获取用户信息
        auth_user_info = getattr(request, 'user_info', {})
        auth_user_id = auth_user_info.get('db_user_id')  # 使用数据库用户ID
        
        # 清除数据库中的当前对话ID（如果有认证用户信息）
        if auth_user_id and str(auth_user_id) in user_current_conversations:
            del user_current_conversations[str(auth_user_id)]
            
        return jsonify({
            'success': True,
            'message': '会话已重置'
        })
    except Exception as e:
        logger.error(f"重置会话时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/status', methods=['GET'])
@auth_middleware.login_required
def get_status():
    """获取应用状态信息"""
    try:
        active_users = len(user_current_conversations)
        total_conversations = Conversation.query.filter_by(is_deleted=False).count()
        
        return jsonify({
            'success': True,
            'status': 'running',
            'active_users': active_users,
            'total_conversations': total_conversations,
            'app_version': '2.0.0',
            'python_version': '3.12',
            'config': {
                'max_message_length': config.max_message_length,
                'max_conversation_history': config.max_conversation_history,
                'rate_limit_requests': config.rate_limit_requests,
                'rate_limit_window': config.rate_limit_window
            }
        })
    except Exception as e:
        logger.error(f"获取状态时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

# ==================== 历史记录相关API ====================

@app.route('/api/conversations', methods=['GET'])
@auth_middleware.login_required
def get_conversations():
    """获取用户的历史对话列表，按时间分组"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        
        if not user_id:
            logger.warning('获取历史记录失败 - 用户ID为空')
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 获取用户对象
        user = User.query.filter_by(user_id=user_id, is_deleted=False).first()
        if not user:
            return jsonify({
                'success': False,
                'error': '用户不存在'
            }), HTTPStatus.NOT_FOUND
        
        # 获取用户的对话列表，按更新时间倒序
        conversations = Conversation.query.filter_by(
            user_id=user_id, 
            is_deleted=False
        ).order_by(Conversation.updated_at.desc()).all()
        
        # 按时间分组
        from datetime import datetime, timedelta
        now = get_beijing_time()
        today = now.date()
        yesterday = today - timedelta(days=1)
        week_ago = today - timedelta(days=7)
        month_ago = today - timedelta(days=30)
        
        grouped_conversations = {
            'today': [],
            'yesterday': [],
            'week': [],
            'month': []
        }
        
        for conv in conversations:
            conv_date = conv.updated_at.date()
            conv_data = {
                'conversation_id': conv.conversation_id,
                'title': conv.title,
                'message_count': conv.message_count,
                'session_id': conv.session_id,
                'last_message_at': conv.last_message_at.isoformat() if conv.last_message_at else None,
                'created_at': conv.created_at.isoformat(),
                'updated_at': conv.updated_at.isoformat()
            }
            
            if conv_date == today:
                grouped_conversations['today'].append(conv_data)
            elif conv_date == yesterday:
                grouped_conversations['yesterday'].append(conv_data)
            elif conv_date >= week_ago:
                grouped_conversations['week'].append(conv_data)
            elif conv_date >= month_ago:
                grouped_conversations['month'].append(conv_data)
        
        return jsonify({
            'success': True,
            'conversations': grouped_conversations
        })
        
    except Exception as e:
        logger.error(f"获取对话列表时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/<int:conversation_id>', methods=['GET'])
@auth_middleware.login_required
def get_conversation_messages(conversation_id):
    """获取指定对话的所有消息"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 验证对话是否属于当前用户
        conversation = Conversation.query.filter_by(
            conversation_id=conversation_id,
            user_id=user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            return jsonify({
                'success': False,
                'error': '对话不存在或无权限访问'
            }), HTTPStatus.NOT_FOUND
        
        # 获取对话的所有消息，按顺序排列
        messages = Message.query.filter_by(
            conversation_id=conversation_id,
            is_deleted=False
        ).order_by(Message.message_order.asc()).all()
        
        messages_data = []
        for msg in messages:
            message_data = {
                'message_id': msg.message_id,
                'role': msg.role,
                'content': msg.content,
                'thinking_content': msg.thinking_content,
                'content_type': msg.content_type,
                'message_order': msg.message_order,
                'created_at': msg.created_at.isoformat()
            }
            messages_data.append(message_data)
        
        return jsonify({
            'success': True,
            'conversation': {
                'conversation_id': conversation.conversation_id,
                'title': conversation.title,
                'conversation_type': conversation.conversation_type,
                'session_id': conversation.session_id,
                'message_count': conversation.message_count,
                'created_at': conversation.created_at.isoformat(),
                'updated_at': conversation.updated_at.isoformat()
            },
            'messages': messages_data
        })
        
    except Exception as e:
        logger.error(f"获取对话消息时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/<int:conversation_id>/rename', methods=['POST'])
@auth_middleware.login_required
def rename_conversation(conversation_id):
    """重命名对话"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        data = request.json or {}
        new_title = data.get('title', '').strip()
        
        if not new_title:
            return jsonify({
                'success': False,
                'error': '新标题不能为空'
            }), HTTPStatus.BAD_REQUEST
        
        if len(new_title) > 500:
            return jsonify({
                'success': False,
                'error': '标题长度不能超过500个字符'
            }), HTTPStatus.BAD_REQUEST
        
        # 验证对话是否属于当前用户
        conversation = Conversation.query.filter_by(
            conversation_id=conversation_id,
            user_id=user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            return jsonify({
                'success': False,
                'error': '对话不存在或无权限访问'
            }), HTTPStatus.NOT_FOUND
        
        # 更新标题
        conversation.title = new_title
        conversation.updated_at = get_beijing_time()
        
        db.session.commit()
        
        return jsonify({
            'success': True,
            'message': '对话标题已更新',
            'conversation': {
                'conversation_id': conversation.conversation_id,
                'title': conversation.title,
                'updated_at': conversation.updated_at.isoformat()
            }
        })
        
    except Exception as e:
        db.session.rollback()
        logger.error(f"重命名对话时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/<int:conversation_id>', methods=['DELETE'])
@auth_middleware.login_required
def delete_conversation(conversation_id):
    """删除对话（软删除）"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 验证对话是否属于当前用户
        conversation = Conversation.query.filter_by(
            conversation_id=conversation_id,
            user_id=user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            return jsonify({
                'success': False,
                'error': '对话不存在或无权限访问'
            }), HTTPStatus.NOT_FOUND
        
        # 软删除对话
        conversation.is_deleted = True
        conversation.deleted_at = get_beijing_time()
        conversation.updated_at = get_beijing_time()
        
        # 同时软删除该对话的所有消息
        Message.query.filter_by(
            conversation_id=conversation_id,
            is_deleted=False
        ).update({
            'is_deleted': True,
            'deleted_at': get_beijing_time()
        })
        
        db.session.commit()
        
        return jsonify({
            'success': True,
            'message': '对话已删除'
        })
        
    except Exception as e:
        db.session.rollback()
        logger.error(f"删除对话时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/new', methods=['POST'])
@auth_middleware.login_required
def create_new_conversation():
    """创建新对话"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 获取用户对象
        user = User.query.filter_by(user_id=user_id, is_deleted=False).first()
        if not user:
            return jsonify({
                'success': False,
                'error': '用户不存在'
            }), HTTPStatus.NOT_FOUND
        
        data = request.json or {}
        title = data.get('title', '新对话').strip()
        
        if not title:
            title = '新对话'
        
        if len(title) > 500:
            return jsonify({
                'success': False,
                'error': '标题长度不能超过500个字符'
            }), HTTPStatus.BAD_REQUEST
        
        # 生成新的session_id
        session_id = generate_session_id(user_id)
        
        # 创建新对话
        conversation = Conversation(
            user_id=user_id,
            title=title,
            conversation_type='chat',
            session_id=session_id,
            message_count=0
        )
        
        db.session.add(conversation)
        db.session.commit()
        
        # 更新用户的当前对话ID
        user_current_conversations[str(user_id)] = conversation.conversation_id
        
        
        return jsonify({
            'success': True,
            'message': '新对话已创建',
            'conversation': {
                'conversation_id': conversation.conversation_id,
                'title': conversation.title,
                'created_at': conversation.created_at.isoformat(),
                'updated_at': conversation.updated_at.isoformat()
            }
        })
        
    except Exception as e:
        db.session.rollback()
        logger.error(f"创建新对话时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/clear-current', methods=['POST'])
@auth_middleware.login_required
def clear_current_conversation():
    """清除用户的当前对话映射，强制下次创建新对话"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 清除用户的当前对话映射
        if str(user_id) in user_current_conversations:
            del user_current_conversations[str(user_id)]
        
        return jsonify({
            'success': True,
            'message': '当前对话映射已清除'
        })
        
    except Exception as e:
        logger.error(f"清除当前对话映射时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/<int:conversation_id>/switch', methods=['POST'])
@auth_middleware.login_required
def switch_conversation(conversation_id):
    """切换到指定对话"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 切换到指定对话
        conversation = switch_to_conversation(user_id, conversation_id)
        
        return jsonify({
            'success': True,
            'message': '对话切换成功',
            'conversation': {
                'conversation_id': conversation.conversation_id,
                'title': conversation.title,
                'session_id': conversation.session_id,
                'message_count': conversation.message_count,
                'last_message_at': conversation.last_message_at.isoformat() if conversation.last_message_at else None,
                'created_at': conversation.created_at.isoformat(),
                'updated_at': conversation.updated_at.isoformat()
            }
        })
        
    except ValueError as e:
        return jsonify({
            'success': False,
            'error': str(e)
        }), HTTPStatus.NOT_FOUND
    except Exception as e:
        logger.error(f"切换对话时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/conversations/<int:conversation_id>/status', methods=['GET'])
@auth_middleware.login_required
def get_conversation_status(conversation_id):
    """获取对话的实时状态信息"""
    try:
        # 从认证中间件获取用户信息
        user_info = getattr(request, 'user_info', {})
        user_id = user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not user_id:
            return jsonify({
                'success': False,
                'error': '用户信息获取失败'
            }), HTTPStatus.UNAUTHORIZED
        
        # 验证对话是否属于当前用户
        conversation = Conversation.query.filter_by(
            conversation_id=conversation_id,
            user_id=user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            return jsonify({
                'success': False,
                'error': '对话不存在或无权限访问'
            }), HTTPStatus.NOT_FOUND
        
        # 获取对话的最新消息
        latest_message = Message.query.filter_by(
            conversation_id=conversation_id,
            is_deleted=False
        ).order_by(Message.message_order.desc()).first()
        
        status_info = {
            'conversation_id': conversation_id,
            'title': conversation.title,
            'message_count': conversation.message_count,
            'last_message_at': conversation.last_message_at.isoformat() if conversation.last_message_at else None,
            'updated_at': conversation.updated_at.isoformat(),
            'has_latest_message': latest_message is not None,
            'latest_message_role': latest_message.role if latest_message else None,
            'latest_message_preview': latest_message.content[:100] + '...' if latest_message and len(latest_message.content) > 100 else latest_message.content if latest_message else None
        }
        
        return jsonify({
            'success': True,
            'status': status_info
        })
        
    except Exception as e:
        logger.error(f"获取对话状态时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR

@app.route('/api/messages/<int:message_id>/edit', methods=['POST'])
@auth_middleware.login_required
@rate_limit(config.rate_limit_requests, config.rate_limit_window)
def edit_message(message_id):
    """编辑用户消息并重新生成AI回复（流式响应）"""
    try:
        # 从请求中获取数据
        data = request.json or {}
        new_content = data.get('content', '')
        agent = data.get('agent') or 'kuaishou'
        
        # 输入验证
        new_content, error = sanitize_input(new_content, config.max_message_length)
        if error:
            # 流式响应中的错误返回
            return Response(
                f"data: {json.dumps({'success': False, 'error': error, 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 从认证中间件获取用户信息
        auth_user_info = getattr(request, 'user_info', {})
        auth_user_id = auth_user_info.get('db_user_id')  # 使用数据库用户ID
        
        if not auth_user_id:
            return Response(
                f"data: {json.dumps({'success': False, 'error': '用户信息获取失败', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 获取要编辑的消息
        message = Message.query.filter_by(
            message_id=message_id,
            is_deleted=False
        ).first()
        
        if not message:
            return Response(
                f"data: {json.dumps({'success': False, 'error': '消息不存在', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 验证消息是否是用户消息
        if message.role != 'user':
            return Response(
                f"data: {json.dumps({'success': False, 'error': '只能编辑用户消息', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 获取对话信息
        conversation = Conversation.query.filter_by(
            conversation_id=message.conversation_id,
            user_id=auth_user_id,
            is_deleted=False
        ).first()
        
        if not conversation:
            return Response(
                f"data: {json.dumps({'success': False, 'error': '对话不存在或无权限访问', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 记录请求信息
        log_request_info(new_content, str(auth_user_id), 'POST')
        
        # 选择对应智能体 APP_ID
        chosen_app_id, appid_env_key = config.get_app_id_for_agent_with_source(agent)
        if not chosen_app_id:
            logger.error(f"未找到对应智能体APP_ID，agent={agent}")
            return Response(
                f"data: {json.dumps({'success': False, 'error': f'服务器未配置该智能体的 APP_ID: {agent}', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 使用对话的session_id
        api_session_id = conversation.session_id
        
        # ===== 立即软删除当前消息及之后的所有消息（在流式响应开始前） =====
        try:
            # 计算将被删除的消息数（包括当前消息及之后的所有消息）
            deleted_count = Message.query.filter_by(
                conversation_id=conversation.conversation_id,
                is_deleted=False
            ).filter(
                Message.message_order >= message.message_order
            ).count()
            
            # 软删除当前消息及之后的所有消息（包括原来的AI回复等）
            Message.query.filter_by(
                conversation_id=conversation.conversation_id,
                is_deleted=False
            ).filter(
                Message.message_order >= message.message_order
            ).update({
                'is_deleted': True,
                'deleted_at': get_beijing_time()
            }, synchronize_session=False)
            
            # 更新消息计数：减去被删除的消息数
            conversation.message_count -= deleted_count
            db.session.commit()
            
            # 保存编辑后的用户消息（使用相同的message_order）
            new_user_message = save_message_to_database(
                auth_user_id,
                conversation.conversation_id,
                'user',
                new_content,
                None,
                message_order=message.message_order
            )
            
        except Exception as db_error:
            db.session.rollback()
            logger.error(f"软删除消息或保存编辑消息时发生错误: {str(db_error)}", exc_info=True)
            return Response(
                f"data: {json.dumps({'success': False, 'error': f'更新消息失败: {str(db_error)}', 'done': True})}\n\n",
                content_type='text/event-stream'
            )
        
        # 获取该消息之前的所有消息（不包括已删除的消息，现在数据库中已删除的消息不会出现在查询结果中）
        previous_messages = Message.query.filter_by(
            conversation_id=message.conversation_id,
            is_deleted=False
        ).filter(
            Message.message_order < message.message_order
        ).order_by(Message.message_order.asc()).all()
        
        # 构建对话历史（使用编辑后的消息）
        messages = []
        for msg in previous_messages:
            messages.append({"role": msg.role, "content": msg.content})
        
        # 添加编辑后的用户消息（刚保存的）
        messages.append({"role": "user", "content": new_content})
        
        # 截断对话历史以控制内存使用
        messages = truncate_conversation_history(messages, config.max_conversation_history)
        
        # 定义流式响应生成器
        def generate() -> Generator[str, None, None]:
            try:
                # 发送初始响应
                initial_data = {
                    'success': True,
                    'chunk': '',
                    'done': False,
                    'agent': agent,
                    'message_id': message_id
                }
                yield f"data: {json.dumps(initial_data)}\n\n"
                
                try:
                    # 使用DashScope SDK直接调用 - 多轮对话模式
                    params = {
                        "api_key": config.api_key,
                        "app_id": chosen_app_id,
                        "messages": messages,  # 发送完整的对话历史
                        "stream": True,
                        "incremental_output": True,
                        "has_thoughts": True
                    }
                    
                    # 使用对话的session_id
                    if api_session_id:
                        params["session_id"] = api_session_id
                    
                    response = Application.call(**params)
                    
                    new_session_id: Optional[str] = None
                    accumulated_text: str = ""
                    thoughts_content: List[str] = []
                    
                    # 处理流式响应
                    for chunk in response:
                        # 检查客户端是否断开连接
                        if request.environ.get('werkzeug.server.shutdown') or not request:
                            break
                            
                        if chunk.status_code != HTTPStatus.OK:
                            yield f"data: {json.dumps({'success': False, 'error': f'错误: {chunk.status_code} - {chunk.message}', 'request_id': chunk.request_id, 'done': True, 'agent': agent})}\n\n"
                            return
                        
                        # 处理思考过程
                        if hasattr(chunk.output, 'thoughts') and chunk.output.thoughts:
                            for it in chunk.output.thoughts:
                                if it.action_type == 'reasoning':
                                    content = str(it.thought) if not isinstance(it.thought, str) else it.thought
                                    thoughts_content.append(content)
                                    yield f"data: {json.dumps({'success': True, 'thought': content, 'done': False, 'agent': agent})}\n\n"
                        
                        # 处理回答内容
                        if hasattr(chunk.output, 'text') and chunk.output.text:
                            current_text = str(chunk.output.text)
                            accumulated_text += current_text
                            yield f"data: {json.dumps({'success': True, 'chunk': current_text, 'done': False, 'agent': agent})}\n\n"
                        
                        # 检查是否有会话ID
                        if hasattr(chunk.output, 'session_id') and chunk.output.session_id:
                            new_session_id = chunk.output.session_id
                    
                    # 处理结束，保存AI回复到数据库
                    try:
                        # 更新session_id（如果需要）
                        if new_session_id and new_session_id != api_session_id:
                            conversation.session_id = new_session_id
                            db.session.commit()
                        
                        # 保存新的AI回复（如果有）
                        if accumulated_text:
                            thinking_text = '\n'.join(thoughts_content) if thoughts_content else None
                            ai_message = save_message_to_database(
                                auth_user_id,
                                conversation.conversation_id,
                                'assistant',
                                accumulated_text,
                                thinking_text,
                                message_order=message.message_order + 1
                            )
                            # save_message_to_database 已经提交，message_count 已更新
                        else:
                            # 如果没有AI回复，更新对话的更新时间
                            conversation.updated_at = get_beijing_time()
                            conversation.last_message_at = get_beijing_time()
                            db.session.commit()
                        
                    except Exception as db_error:
                        db.session.rollback()
                        logger.error(f"保存AI回复到数据库时发生错误: {str(db_error)}", exc_info=True)
                        # 不影响主要功能，继续返回结果
                    
                    # 发送完成标记
                    final_data = {
                        'success': True,
                        'done': True,
                        'thoughts': thoughts_content,
                        'agent': agent,
                        'session_id': new_session_id or api_session_id,
                        'message_id': message_id,
                        'conversation_id': conversation.conversation_id
                    }
                    
                    yield f"data: {json.dumps(final_data)}\n\n"
                    
                except Exception as e:
                    logger.error(f"DashScope SDK 调用错误: {str(e)}", exc_info=True)
                    yield f"data: {json.dumps({'success': False, 'error': f'DashScope API调用错误: {str(e)}', 'done': True, 'agent': agent})}\n\n"
            
            except Exception as e:
                logger.error(f"流式API调用错误: {str(e)}", exc_info=True)
                yield f"data: {json.dumps({'success': False, 'error': f'发生错误: {str(e)}', 'done': True, 'agent': agent})}\n\n"
        
        # 创建并返回流式响应
        response = Response(stream_with_context(generate()), content_type='text/event-stream')
        response.headers['Cache-Control'] = 'no-cache'
        response.headers['X-Accel-Buffering'] = 'no'
        return response
    
    except Exception as e:
        logger.error(f"编辑消息时发生错误: {str(e)}", exc_info=True)
        return jsonify({
            'success': False,
            'error': f"发生错误: {str(e)}"
        }), HTTPStatus.INTERNAL_SERVER_ERROR
    

# 健康检查端点
@app.route('/health', methods=['GET'])
def health_check():
    """健康检查端点"""
    return jsonify({
        'status': 'ok',
        'app_version': '2.0.0',
        'python_version': '3.12',
        'timestamp': time.time()
    })

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=config.port, debug=config.debug)