"""
handlers.py - 用户登录和聊天的处理器
"""
import tornado.web
import tornado.websocket

nicknames = set()
connections = {}


class LoginHandler(tornado.web.RequestHandler):

    def get(self):
        self.render('login.html', hint='')

    def post(self):
        nickname = self.get_argument('nickname')
        if nickname in nicknames:
            self.render('login.html', hint='昵称已被使用，请更换昵称')
        self.set_secure_cookie('nickname', nickname)
        self.render('chat.html')


class ChatHandler(tornado.websocket.WebSocketHandler):

    def open(self):
        nickname = self.get_secure_cookie('nickname').decode()
        nicknames.add(nickname)
        for conn in connections.values():
            conn.write_message(f'~~~{nickname}进入了聊天室~~~')
        connections[nickname] = self

    def on_message(self, message):
        nickname = self.get_secure_cookie('nickname').decode()
        for conn in connections.values():
            if conn is not self:
                conn.write_message(f'{nickname}说：{message}')

    def on_close(self):
        nickname = self.get_secure_cookie('nickname').decode()
        del connections[nickname]
        nicknames.remove(nickname)
        for conn in connections.values():
            conn.write_message(f'~~~{nickname}离开了聊天室~~~')