const LOGIN_URL_PATTERN = /https?:\/\/[^\s]+\/login\?[^\s]+/g;
const LOOPBACK_HOSTS = new Set(["localhost", "127.0.0.1", "[::1]"]);

export function parseMulticaLoginOutput(output) {
  const matches = String(output || "").match(LOGIN_URL_PATTERN) || [];
  const loginUrl = new URL(matches.at(-1) || "");
  const callbackUrl = new URL(loginUrl.searchParams.get("cli_callback") || "");
  const state = loginUrl.searchParams.get("cli_state") || "";
  const port = Number(callbackUrl.port);

  if (callbackUrl.protocol !== "http:" || !LOOPBACK_HOSTS.has(callbackUrl.hostname) || callbackUrl.pathname !== "/callback") {
    throw new Error("Multica 尚未生成有效的本机回调地址");
  }
  if (!Number.isInteger(port) || port < 1024 || port > 65535 || !state) {
    throw new Error("Multica 登录链接缺少端口或 state");
  }
  return { loginUrl, callbackUrl, state };
}

export function buildManagedMulticaLoginUrl(output, publicOrigin, sessionId) {
  const { loginUrl } = parseMulticaLoginOutput(output);
  const managedCallback = new URL(`/api/integrations/multica/oauth/callback/${encodeURIComponent(sessionId)}`, publicOrigin);
  loginUrl.searchParams.set("cli_callback", managedCallback.toString());
  return loginUrl.toString();
}

export function buildLocalMulticaCallbackUrl(output, query) {
  const { callbackUrl, state } = parseMulticaLoginOutput(output);
  const returnedState = typeof query?.state === "string" ? query.state : "";
  const token = typeof query?.token === "string" ? query.token : "";
  if (!token || !returnedState || returnedState !== state) throw new Error("Multica 回调校验失败，请重新发起验证");
  callbackUrl.search = "";
  callbackUrl.searchParams.set("token", token);
  callbackUrl.searchParams.set("state", returnedState);
  return callbackUrl.toString();
}