"""帧编解码与注册地址推导。"""

from __future__ import annotations

import json
from typing import Any
from urllib.parse import urlparse, urlunparse


def dumps(obj: dict[str, Any]) -> bytes:
    return json.dumps(obj, ensure_ascii=False, separators=(",", ":")).encode("utf-8")


def loads(data: bytes | str) -> dict[str, Any]:
    if isinstance(data, bytes):
        data = data.decode("utf-8")
    return json.loads(data)


def register_url_from_connect(connect_url: str) -> str:
    """从连接地址推出注册 HTTP 地址（DEVELOPMENT 6.9）。"""
    raw = connect_url.strip()
    if "://" not in raw:
        raw = "ws://" + raw
    u = urlparse(raw)
    scheme = u.scheme.lower()
    if scheme in ("wss", "mqtts", "https"):
        http_scheme = "https"
    elif scheme in ("ws", "mqtt", "http"):
        http_scheme = "http"
    else:
        http_scheme = "https" if scheme.endswith("s") else "http"
    # 去掉 /mqtt 路径
    path = u.path or ""
    if path.endswith("/mqtt"):
        path = path[: -len("/mqtt")]
    path = path.rstrip("/") + "/api/client/register"
    return urlunparse((http_scheme, u.netloc, path, "", "", ""))


def up_topic(endpoint_id: str) -> str:
    return f"nix/c/{endpoint_id}/up"


def down_topic(endpoint_id: str) -> str:
    return f"nix/c/{endpoint_id}/down"


def normalize_mqtt_ws_url(url: str, *, allow_tcp: bool = False) -> str:
    """http→ws、https→wss；路径为空或 / 时用 /mqtt，否则保留；mqtt/mqtts 仅显式允许裸 TCP。"""
    raw = url.strip()
    if "://" not in raw:
        raw = "ws://" + raw
    u = urlparse(raw)
    scheme = u.scheme.lower()
    if scheme == "http":
        scheme = "ws"
    elif scheme == "https":
        scheme = "wss"
    if scheme in ("mqtt", "mqtts"):
        if not allow_tcp:
            raise ValueError("裸 TCP 需显式 use_tcp")
        return urlunparse((scheme, u.netloc, u.path, u.params, u.query, u.fragment))
    if scheme not in ("ws", "wss"):
        raise ValueError(f"unsupported scheme {u.scheme}")
    path = u.path or ""
    if path in ("", "/"):
        path = "/mqtt"
    return urlunparse((scheme, u.netloc, path, u.params, u.query, u.fragment))