# mcp_chat_api.py - MCP 聊天 API 端点
# 添加到 app.py 或作为独立模块导入

from flask import Blueprint, request, jsonify, session, Response
import json
import time
from typing import Generator

# 创建蓝图
mcp_chat_bp = Blueprint('mcp_chat', __name__, url_prefix='/api/mcp')

# 假设已有 mcp_server.py 中的相关功能
# from mcp_server import process_message, get_available_tools, execute_code

def check_chat_permission():
    """检查用户是否有权限访问 AI 聊天功能"""
    if not session.get('user_id'):
        return False, '请先登录'

    # 这里可以添加订阅检查逻辑
    # user = User.query.get(session['user_id'])
    # if user.subscription_tier not in ['premium', 'pro', 'enterprise']:
    #     return False, '需要订阅才能使用 AI 助手'

    return True, None

@mcp_chat_bp.route('/chat', methods=['POST'])
def chat():
    """处理聊天消息"""
    # 权限检查
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    data = request.json
    message = data.get('message', '')
    session_id = data.get('sessionId', '')
    model = data.get('model', 'claude-3-opus')

    if not message:
        return jsonify({'error': '消息不能为空'}), 400

    try:
        # 调用 MCP 处理消息
        # response = process_message(
        #     message=message,
        #     user_id=session['user_id'],
        #     session_id=session_id,
        #     model=model
        # )

        # 临时模拟响应
        response = {
            'reply': f'收到您的消息: "{message}"。这是一个模拟响应，实际部署时会调用 MCP 模型。',
            'sessionId': session_id,
            'timestamp': time.time()
        }

        return jsonify(response)

    except Exception as e:
        print(f"Chat error: {e}")
        return jsonify({'error': '处理消息时出错'}), 500

@mcp_chat_bp.route('/chat/stream', methods=['POST'])
def chat_stream():
    """流式处理聊天消息"""
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    data = request.json
    message = data.get('message', '')
    session_id = data.get('sessionId', '')

    def generate() -> Generator[str, None, None]:
        """生成 SSE 流"""
        try:
            # 这里应该调用实际的 MCP 流式 API
            # for chunk in mcp_stream_message(message, session_id):
            #     yield f"data: {json.dumps(chunk)}\n\n"

            # 临时模拟流式响应
            words = f'这是对 "{message}" 的流式响应。每个字会逐个发送。'.split()
            for word in words:
                chunk = {'content': word + ' ', 'type': 'text'}
                yield f"data: {json.dumps(chunk)}\n\n"
                time.sleep(0.1)  # 模拟延迟

            yield "data: [DONE]\n\n"

        except Exception as e:
            error_chunk = {'error': str(e), 'type': 'error'}
            yield f"data: {json.dumps(error_chunk)}\n\n"

    return Response(
        generate(),
        mimetype='text/event-stream',
        headers={
            'Cache-Control': 'no-cache',
            'X-Accel-Buffering': 'no',  # Nginx 不缓冲
        }
    )

@mcp_chat_bp.route('/tools', methods=['GET'])
def get_tools():
    """获取可用的 MCP 工具列表"""
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    # 这里应该返回实际的工具列表
    tools = [
        {
            'id': 'code_executor',
            'name': '代码执行器',
            'description': '执行 Python、JavaScript 等代码',
            'icon': 'code'
        },
        {
            'id': 'web_search',
            'name': '网页搜索',
            'description': '搜索网络信息',
            'icon': 'search'
        },
        {
            'id': 'calculator',
            'name': '计算器',
            'description': '执行数学计算',
            'icon': 'calculator'
        }
    ]

    return jsonify(tools)

@mcp_chat_bp.route('/execute', methods=['POST'])
def execute_code():
    """执行代码"""
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    data = request.json
    code = data.get('code', '')
    language = data.get('language', 'python')

    if not code:
        return jsonify({'error': '代码不能为空'}), 400

    try:
        # 实际执行代码
        # result = execute_code_safely(code, language)

        # 临时模拟
        result = {
            'output': f'执行 {language} 代码成功\n输出: Hello World',
            'error': None,
            'executionTime': 0.023
        }

        return jsonify(result)

    except Exception as e:
        return jsonify({'error': str(e)}), 500

@mcp_chat_bp.route('/generate-code', methods=['POST'])
def generate_code():
    """生成代码"""
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    data = request.json
    prompt = data.get('prompt', '')
    language = data.get('language', 'python')

    if not prompt:
        return jsonify({'error': '提示不能为空'}), 400

    try:
        # 调用 MCP 生成代码
        # code = mcp_generate_code(prompt, language)

        # 临时模拟
        code = f'''# {prompt}
def hello_world():
    print("Hello, World!")

if __name__ == "__main__":
    hello_world()'''

        return jsonify({
            'code': code,
            'language': language,
            'prompt': prompt
        })

    except Exception as e:
        return jsonify({'error': str(e)}), 500

@mcp_chat_bp.route('/history', methods=['GET'])
def get_history():
    """获取聊天历史"""
    has_permission, error_msg = check_chat_permission()
    if not has_permission:
        return jsonify({'error': error_msg}), 401 if error_msg == '请先登录' else 403

    session_id = request.args.get('sessionId')

    # 这里应该从数据库获取历史
    # history = ChatHistory.query.filter_by(
    #     user_id=session['user_id'],
    #     session_id=session_id
    # ).all()

    # 临时模拟
    history = [
        {
            'role': 'user',
            'content': '你好',
            'timestamp': '2024-01-01T10:00:00Z'
        },
        {
            'role': 'assistant',
            'content': '你好！有什么可以帮助您的吗？',
            'timestamp': '2024-01-01T10:00:01Z'
        }
    ]

    return jsonify(history)

# 在 app.py 中注册蓝图
# app.register_blueprint(mcp_chat_bp)