import socket


class TcpServer:
    def __init__(self, host="0.0.0.0", port=65444) -> None:
        self.host = host
        self.port = port
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.bind((self.host, self.port))
        self.sock.listen(1)  # 允许最多一个连接（可改大）
        print(f"Listening on {self.host}:{self.port}")

    def accept_client(self):
        self.conn, self.addr = self.sock.accept()
        self.conn.setblocking(False)
        print(f"Connected by {self.addr}")

    def recv_data(self, bufsize=4096):
        try:
            data = self.conn.recv(bufsize)
            return data
        except BlockingIOError:
            return ""

    def send_data(self, data: bytes):
        self.conn.sendall(data)

    def conn_close(self):
        self.conn.close()

    def close(self):
        self.sock.close()