"""第三方 RRPP Client JSON 订阅的下载、校验与展示辅助。"""

import json
import urllib.request
from urllib.parse import urlsplit, urlunsplit


def fetch_nodes(url: str, timeout=15):
    """直连读取一个第三方订阅，避免首次导入受系统代理残留影响。"""
    opener = urllib.request.build_opener(urllib.request.ProxyHandler({}))
    request = urllib.request.Request(
        url,
        headers={"Accept": "application/json", "User-Agent": "RRPP-Lite"},
    )
    with opener.open(request, timeout=timeout) as response:
        return validate_nodes(json.loads(response.read().decode("utf-8-sig")))


def validate_nodes(data):
    """校验 RRPP Client 节点数组，返回可安全写入本地缓存的副本。"""
    if not isinstance(data, list) or not data:
        raise ValueError("订阅应为非空的 JSON 节点数组")
    result = []
    for index, node in enumerate(data, 1):
        if not isinstance(node, dict):
            raise ValueError(f"第 {index} 项不是节点对象")
        domain = str(node.get("domain") or "").strip()
        method = (node.get("methods") or {}).get("http") or {}
        port = method.get("port", node.get("port"))
        try:
            port = int(port)
        except (TypeError, ValueError):
            port = 0
        if not domain:
            raise ValueError(f"第 {index} 项缺少 domain")
        if not 1 <= port <= 65535:
            raise ValueError(f"第 {index} 项的 HTTP 代理端口无效")
        result.append(dict(node))
    return result


def mask_url(url: str) -> str:
    """用于 UI 展示，隐藏查询参数和 URL 用户信息中的敏感令牌。"""
    try:
        parts = urlsplit(str(url))
        host = parts.hostname or ""
        if parts.port:
            host = f"{host}:{parts.port}"
        if parts.username:
            host = "***@" + host
        return urlunsplit((parts.scheme, host, parts.path, "…" if parts.query else "", ""))
    except Exception:
        return "已隐藏订阅地址"