/**
 * 敏感信息守卫:工具输入输出进入模型上下文、事件流、审计前统一经过这里。
 * 覆盖 cookie / passkey / token / apiKey / authorization / 含 passkey 等私密参数的 URL / URL 内嵌账号密码。
 * 宁可多遮不可漏遮:误伤只影响可读性,漏遮会把凭证送给外部模型。
 */
export const REDACTED = "[REDACTED]";

const SENSITIVE_KEY_PARTS = [
  "cookie",
  "passkey",
  "authkey",
  "torrentpass",
  "rsskey",
  "apikey",
  "authorization",
  "secret",
  "password",
  "passwd",
  "credential",
  "privatekey",
];

/** 规范化键名(去掉 - _ 并小写)后判断。以 token 结尾算敏感,tokens(用量统计)不算。 */
export function isSensitiveKey(key: string): boolean {
  const k = key.toLowerCase().replace(/[-_\s]/g, "");
  if (k.endsWith("token")) return true;
  if (k === "sign" || k === "signature") return true;
  return SENSITIVE_KEY_PARTS.some((part) => k.includes(part));
}

/** URL 查询参数/片段中视为凭证的参数名 */
const SENSITIVE_PARAM =
  "passkey|authkey|torrent_pass|rsskey|api[_-]?key|access[_-]?token|refresh[_-]?token|token|auth|sign|signature|credential|secret|password|key|uid_key|downhash";
const PARAM_RE = new RegExp(`([?&;#]|\\b)(${SENSITIVE_PARAM})=([^&;#\\s"'<>]+)`, "gi");
const URL_USERINFO_RE = /\b([a-z][a-z0-9+.-]*:\/\/)([^/\s:@]+):([^/\s@]+)@/gi;
const BEARER_RE = /\b(Bearer|Basic|Token)\s+[A-Za-z0-9._~+/=-]{6,}/g;
const HEADER_RE = /\b(cookie|set-cookie|authorization|x-api-key)\s*:\s*[^\r\n]+/gi;
const KNOWN_KEY_RE = /\b(sk-[A-Za-z0-9_-]{8,}|sk-ant-[A-Za-z0-9_-]{8,}|gh[pousr]_[A-Za-z0-9]{16,})\b/g;

export function redactString(input: string): string {
  return input
    .replace(HEADER_RE, (_m, name: string) => `${name}: ${REDACTED}`)
    .replace(URL_USERINFO_RE, (_m, scheme: string) => `${scheme}${REDACTED}@`)
    .replace(PARAM_RE, (_m, lead: string, name: string) => `${lead}${name}=${REDACTED}`)
    .replace(BEARER_RE, (_m, scheme: string) => `${scheme} ${REDACTED}`)
    .replace(KNOWN_KEY_RE, REDACTED);
}

/** 深度脱敏,返回新对象;不修改入参。循环引用替换为 "[Circular]"。 */
export function redactForModel<T>(value: T): T {
  return redactValue(value, new WeakSet()) as T;
}

function redactValue(value: unknown, seen: WeakSet<object>): unknown {
  if (typeof value === "string") return redactString(value);
  if (value === null || typeof value !== "object") return value;
  if (value instanceof Date) return value;
  if (value instanceof URL) return redactString(value.toString());
  if (seen.has(value)) return "[Circular]";
  seen.add(value);
  if (Array.isArray(value)) return value.map((item) => redactValue(item, seen));
  if (value instanceof Map) {
    return Object.fromEntries(
      [...value.entries()].map(([k, v]) => [String(k), isSensitiveKey(String(k)) ? REDACTED : redactValue(v, seen)]),
    );
  }
  const out: Record<string, unknown> = {};
  for (const [k, v] of Object.entries(value)) {
    out[k] = isSensitiveKey(k) && v !== null && v !== undefined && v !== "" ? REDACTED : redactValue(v, seen);
  }
  return out;
}

/** 事件/审计用的短摘要:先脱敏再截断 */
export function summarizeForLog(value: unknown, maxLength = 500): string {
  let text: string;
  try {
    text = typeof value === "string" ? redactString(value) : (JSON.stringify(redactForModel(value)) ?? "undefined");
  } catch {
    text = "[unserializable]";
  }
  return text.length > maxLength ? `${text.slice(0, maxLength)}…(${text.length - maxLength} more)` : text;
}