# -*- coding: utf-8 -*-
"""
隧道控制面协议：服务端与客户端之间 JSON 文本行。
"""
from __future__ import annotations

import json


def register_message(worker_id: str, local_port: int) -> dict:
    """客户端注册：暴露的 worker_id 与本地端口。"""
    return {"type": "register", "worker_id": worker_id, "local_port": local_port}


def register_ack_message(proxy_port: int) -> dict:
    """服务端确认：分配给的代理端口。"""
    return {"type": "register_ack", "proxy_port": proxy_port}


def open_stream_message(stream_id: int, local_port: int) -> dict:
    """服务端通知客户端：请为 stream_id 打开本地 local_port 并连到 stream 端口。"""
    return {"type": "open_stream", "stream_id": stream_id, "local_port": local_port}


def encode_control(msg: dict) -> bytes:
    """编码为一行 JSON + 换行。"""
    return (json.dumps(msg, ensure_ascii=False) + "\n").encode("utf-8")


def decode_control(line: bytes) -> dict:
    """解码一行 JSON。"""
    return json.loads(line.decode("utf-8").strip())