import { createHash } from "node:crypto";

export function normalizeDulupayBaseUrl(baseUrl: string) {
  const trimmed = String(baseUrl || "").trim();
  if (!trimmed) return "https://www.dulupay.com";
  return trimmed.replace(/\/+$/, "");
}

function toSignSource(
  params: Record<string, string | number | null | undefined>,
  key: string
) {
  const payload = Object.entries(params)
    .filter(
      ([name, value]) =>
        name !== "sign" &&
        name !== "sign_type" &&
        value !== undefined &&
        value !== null &&
        String(value) !== ""
    )
    .sort(([a], [b]) => (a > b ? 1 : a < b ? -1 : 0))
    .map(([name, value]) => `${name}=${value}`)
    .join("&");

  return `${payload}${key}`;
}

export function signDulupayV1(
  params: Record<string, string | number | null | undefined>,
  key: string
) {
  return createHash("md5").update(toSignSource(params, key), "utf8").digest("hex");
}

export function verifyDulupayV1Sign(
  params: Record<string, string>,
  key: string
) {
  const incomingSign = String(params.sign || "").trim().toLowerCase();
  if (!incomingSign) return false;
  const localSign = signDulupayV1(params, key);
  return incomingSign === localSign;
}