# settings.py

HOST = \'0.0.0.0\'      # 主机名
PORT = 5555            # 端口号
buffersize = 1024    # 缓冲大小
ADDR = HOST, PORT    # 地址

languages = [\'cn\', \'en\']      # \'cn\' -> 中文
language = \'cn\'                # \'en\' -> 英文

curuser = \'\'  # 当前用户

# language.py

from settings import language

if language == \'en\':
    administrator = \'Administrator\'
    txt_administrator_close_chatroom = \'Chatroom closed by Administrator.\'
    txt_uesr_enter_chatroom = \'entered the chatroom.\'
    txt_user_quit_chatroom = \'quited the chatroom.\'
    txt_username = \'username> \'
    txt_user_already_exists = \'Username already exists!\'
    txt_connect_to = \'Connected to\'
    txt_connect_from = \'Connected from\'
elif language == \'cn\':
    administrator = \'管理员\'
    txt_administrator_close_chatroom = \'管理员关闭了聊天室。\'
    txt_uesr_enter_chatroom = \'进入了聊天室。\'
    txt_user_quit_chatroom = \'退出了聊天室。\'
    txt_username = \'用户名> \'
    txt_user_already_exists = \'用户名已存在。\'
    txt_connect_to = \'连接到\'
    txt_connect_from = \'连接从\'

# server.py

# 导入系统模块
import os, sys
# 导入网络编程（传输层）模块
from socket import *
# IO多路复用模块
from select import select
# 设置模块
from settings import *
# 语言模块
from language import *

def main():
    \'main 主函数\'
    server = socket(AF_INET, SOCK_STREAM)  # 建立TCP套接字
    server.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)  # 设置端口可立即重用
    server.bind(ADDR)  # 绑定地址
    server.listen()  # 监听

    # 接收函数
    accept(server)

def accept(server):
    \'accept 服务器接受函数\'

    # 使用select模块的select方法实现IO多路复用监听传输
    rlist = [server, sys.stdin]
    wlist = []
    xlist = []

    while True:
        rs, ws, xs = select(rlist, wlist, xlist)

        for r in rs:
            if r is server:
                # 服务器接受客户端连接
                conn, addr = server.accept()
                # 调用validate函数检查用户名
                if validate(conn):
                    # 将客户端套接字添加到rlist中以监听
                    rlist.append(conn)
                    # 如果用户名注册成功
                    print(txt_connect_from, addr)
                else:
                    conn.close()
            elif r is sys.stdin:
                # 服务器向所有客户端发送系统（管理员）消息
                data = sys.stdin.readline()
                if data == \'\n\':
                    # 如果服务器输入回车，则退出
                    for c in rlist[2:]:
                        c.send(b\'\n\')
                        c.close()
                    server.close()
                    print(txt_administrator_close_chatroom)
                    os._exit(0)
                else:
                    # 如果服务器输入正常语句，通知所有客户端
                    data = administrator + \': \' + data
                    for c in rlist[2:]:
                        c.send(data.encode())
            else:
                # 服务器接受客户端的消息并转发给所有客户端
                data = r.recv(buffersize)
                if not data:
                    # 关闭客户端
                    r.close()
                    rlist.remove(r)
                else:
                    # 转发信息给其他客户端
                    print(data.decode(), end=\'\')
                    for c in rlist[2:]:
                        if c is not r:
                            c.send(data)

def validate(client):
    \'检验用户名 validate username\'
    name = client.recv(buffersize).decode()
    # print(name.decode())
    # print(users)
    if name in users:
        client.send(b\'Username already exists!\')
        return False
    else:
        users.append(name)
        client.send(b\'Welcome!\')
        return True


if __name__ == \'__main__\':
    # 全局变量，管理用户信息
    users = []

    # 主函数
    main()

# client.py

# 导入系统模块
import os, sys
# 导入网络编程（传输层）模块
from socket import *
# IO多路复用模块
from select import select
# 设置模块
from settings import *
# 语言模块
from language import *

def main():
    \'main 主函数\'
    client = socket(AF_INET, SOCK_STREAM)  # 建立TCP套接字

    # 登录函数
    if login(client):
        # 连接函数
        connect(client)

def connect(client):
    \'connect 客户端连接函数\'

    # 使用select模块的select方法实现IO多路复用监听传输
    rlist = [client, sys.stdin]
    wlist = []
    xlist = []

    while True:
        rs, ws, xs = select(rlist, wlist, xlist)

        for r in rs:
            if r is client:
                # 接受服务器发来的消息
                data = client.recv(buffersize)
                if data.decode() == \'\n\':
                    # 如果消息为回车，聊天室关闭
                    client.close()
                    print(txt_administrator_close_chatroom)
                    os._exit(0)
                else:
                    # 打印接收到的信息
                    print(data.decode(), end=\'\')
            elif r is sys.stdin:
                # 发送消息给服务器
                data = sys.stdin.readline()
                if data == \'\n\':
                    # 如果回车，发送退出消息，关闭客户端，退出聊天室
                    data = curuser + \': \' + txt_user_quit_chatroom + \'\n\'
                    client.send(data.encode())
                    client.close()
                    os._exit(0)
                else:
                    # 发信息给服务器
                    data = curuser + \': \' + data
                    client.send(data.encode())

def login(client):
    \'登录函数 login\'
    # 使用全局变量管理用户
    # 先让客户端输入姓名
    global curuser
    curuser = input(txt_username)
    # 再连接到服务器，传送用户名以检验
    client.connect(ADDR)  # 连接到服务器地址
    print(txt_connect_to, ADDR)
    client.send(curuser.encode())
    data = client.recv(buffersize)
    if data.decode() == \'Username already exists!\':
        # 如果用户名已经存在，要求重新输入
        print(txt_user_already_exists)
        return False
    else:
        # 发送信息给服务器，告知服务器用户进入聊天室
        # -*- 因为监听传输的是sys.stdin.readline()，所以必须在最后添加换行符，以便清除阻塞 -*-
        data = curuser + \': \' + txt_uesr_enter_chatroom + \'\n\'
        client.send(data.encode())
        return True


if __name__ == \'__main__\':
    main()