API/CS3.1.py

import threading
import json
from flask import Flask, jsonify, request
import sqlite3
import socket
import secrets
import time
import os

app = Flask(__name__)
socket_server = socket.socket()
socket_server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

# 修改数据结构：使用用户名作为主键
active_connections = {}  # {username: {'conn': conn, 'ip': ip}}
chat_connections = []    # 所有活跃连接列表
tokens = {}              # 令牌管理

def get_db_connection():
    conn = sqlite3.connect("usr.db")
    conn.row_factory = sqlite3.Row
    return conn

def isuserxist(name):
    cn = get_db_connection()
    csr = cn.cursor()
    csr.execute('SELECT * FROM users WHERE name = ?', (name,))
    rst = csr.fetchone()
    cn.close()
    return rst is not None

def ispsswdright(name, passwd):
    cn = get_db_connection()
    csr = cn.cursor()
    csr.execute("SELECT passwd FROM users WHERE name = ?", (name,))
    result = csr.fetchone()
    cn.close()
    return result and result[0] == passwd

def get_avatar(username):
    cn = get_db_connection()
    csr = cn.cursor()
    csr.execute("SELECT avatar FROM users WHERE name = ?", (username,))
    result = csr.fetchone()
    cn.close()
    return result[0] if result else "default_avatar.png"

def register_user(usr, pwd, avatar="default_avatar.png"):
    conn = get_db_connection()
    try:
        cursor = conn.cursor()
        # 添加avatar字段
        cursor.execute("INSERT INTO users (name, passwd, avatar) VALUES (?, ?, ?)",
                       (usr, pwd, avatar))
        conn.commit()
        return {"type": "register_1", "success": True, "message": "User registered successfully"}
    except sqlite3.IntegrityError:
        return {"type": "register_0", "success": False, "message": "Username already exists"}
    except sqlite3.Error as e:
        return {"type": "register_0", "success": False, "message": str(e)}
    finally:
        conn.close()

def generate_token(username):
    token = secrets.token_hex(16)
    tokens[token] = {'username': username, 'timestamp': time.time()}
    return token

def validate_token(token):
    if token in tokens:
        if time.time() - tokens[token]['timestamp'] < 3600:
            tokens[token]['timestamp'] = time.time()
            return tokens[token]['username']
    return None

@app.route("/api/register", methods=['POST'])
def register1():
    vl = request.get_json()
    usr = vl.get('username')
    pwd = vl.get('password')
    avatar = vl.get('avatar', 'default_avatar.png')  # 获取头像

    # 头像验证
    if avatar and not (avatar.endswith('.png') or avatar.endswith('.jpg')):
        return jsonify({
            "type": "register_0",
            "success": False,
            "message": "Invalid avatar format. Only .png or .jpg allowed"
        }), 400

    result = register_user(usr, pwd, avatar)
    if result['success']:
        return jsonify(result)
    else:
        return jsonify(result), 403 if result['message'] == "Username already exists" else 500

@app.route("/api/login", methods=['POST'])
def login():
    data = request.get_json()
    username = data['username']

    # 检查账号是否已登录
    if username in active_connections:
        return jsonify({
            "type": "login_0",
            "status": "error",
            "message": "Account already logged in"
        }), 409  # 冲突状态码

    if isuserxist(username) and ispsswdright(username, data['password']):
        token = generate_token(username)
        avatar = get_avatar(username)
        return jsonify({
            "type": "login_1",
            "status": "success",
            "token": token,
            "avatar": avatar  # 返回头像
        })
    return jsonify({
        "type": "login_0",
        "status": "error",
        "message": "Invalid credentials"
    }), 401

@app.route("/api/avatar/<username>", methods=['GET'])
def get_user_avatar(username):
    avatar = get_avatar(username)
    return jsonify({"username": username, "avatar": avatar})

@app.route("/api/chat", methods=['POST'])
def chat():
    token = request.headers.get('Authorization')
    username = validate_token(token)
    if not username:
        return jsonify({"type": "chat", "status": "error"}), 401

    data = request.get_json()
    message = {
        "type": "chat",
        "user": username,
        "message": data['message'],
        "avatar": get_avatar(username)  # 添加头像信息
    }
    broadcast_message(message)
    return jsonify({"type": "chat", "status": "success"})

def broadcast_message(message, sender=None):
    for conn in chat_connections:
        try:
            conn.sendall(json.dumps(message).encode())
        except:
            # 连接异常时移除
            for uname, info in list(active_connections.items()):
                if info['conn'] == conn:
                    del active_connections[uname]
                    break
            if conn in chat_connections:
                chat_connections.remove(conn)

def handle_socket_message(data, addr, conn):
    try:
        action = data.get('type')
        if action == 'register':
            avatar = data.get('avatar', 'default_avatar.png')
            result = register_user(data.get('username'), data.get('password'), avatar)
            conn.sendall(json.dumps(result).encode())
            return result

        elif action == 'login':
            username = data['username']
            password = data['password']

            # 检查账号是否已登录
            if username in active_connections:
                response = {
                    "type": "login_0",
                    "status": "error",
                    "message": "Account already logged in"
                }
                conn.sendall(json.dumps(response).encode())
                return response

            if isuserxist(username) and ispsswdright(username, password):
                # 移除旧连接（如果存在）
                if username in active_connections:
                    old_conn = active_connections[username]['conn']
                    if old_conn in chat_connections:
                        chat_connections.remove(old_conn)
                    del active_connections[username]

                # 添加新连接
                active_connections[username] = {'conn': conn, 'ip': addr[0]}
                if conn not in chat_connections:
                    chat_connections.append(conn)

                token = generate_token(username)
                avatar = get_avatar(username)
                response = {
                    "type": "login_1",
                    "status": "success",
                    "message": "Login successful",
                    "token": token,
                    "username": username,
                    "avatar": avatar  # 返回头像
                }
                conn.sendall(json.dumps(response).encode())
                return response
            else:
                response = {
                    "type": "login_0",
                    "status": "error",
                    "message": "Invalid credentials"
                }
                conn.sendall(json.dumps(response).encode())
                return response

        elif action == 'chat':
            username = validate_token(data.get('token', ''))
            if not username:
                response = {
                    "type": "chat",
                    "status": "error",
                    "message": "Not authenticated"
                }
                conn.sendall(json.dumps(response).encode())
                return response

            if username not in active_connections:
                response = {
                    "type": "chat",
                    "status": "error",
                    "message": "Not logged in"
                }
                conn.sendall(json.dumps(response).encode())
                return response

            message = {
                "type": "chat",
                "user": username,
                "message": data['message'],
                "avatar": get_avatar(username)  # 添加头像
            }
            broadcast_message(message)
            return {"type": "chat", "status": "success"}

    except Exception as e:
        return {"status": "error", "message": str(e)}

def run_socket_server():
    socket_server.bind(("localhost", 8889))
    socket_server.listen()
    print("Socket server running on port 8889")
    while True:
        conn, addr = socket_server.accept()
        print(f"Socket client connected: {addr}")
        try:
            while True:
                data = conn.recv(1024)
                if not data:
                    break

                try:
                    json_data = json.loads(data.decode())
                    response = handle_socket_message(json_data, addr, conn)
                except json.JSONDecodeError:
                    response = {
                        "type": "error",
                        "status": "error",
                        "message": "Invalid JSON"
                    }
                    conn.sendall(json.dumps(response).encode())
        except (ConnectionResetError, BrokenPipeError):
            print(f"Client {addr} disconnected abruptly")
        finally:
            # 清理断开的连接
            for username, info in list(active_connections.items()):
                if info['conn'] == conn:
                    del active_connections[username]
                    print(f"User {username} disconnected")
                    break

            if conn in chat_connections:
                chat_connections.remove(conn)

            try:
                conn.close()
            except:
                pass
            print(f"Connection closed for {addr}")

if __name__ == '__main__':
    with get_db_connection() as conn:
        # 添加avatar字段
        conn.execute('''CREATE TABLE IF NOT EXISTS users
                      (name TEXT PRIMARY KEY, 
                       passwd TEXT,
                       avatar TEXT)''')
    threading.Thread(target=run_socket_server, daemon=True).start()
    app.run(port=5001)