/**
 * What one stored subscription's reminder should say.
 *
 * Since reminders became personal (lib/reminder.ts), each subscription carries
 * the notification text its own browser composed — already in the user's
 * language, naming their deck when their notes could carry it. Older records
 * (or a browser that never refreshed) have none, so the operator's generic
 * default from the environment is the fallback. Kept in its own module so both
 * the sender and the test suite can exercise it without sending anything.
 */

/** The operator's fallback, from PUSH_REMINDER_* (see .env.example). */
export const DEFAULT_REMINDER = {
  title: "Time to review",
  body: "Your decks are waiting — a few due cards keep the streak alive.",
  url: "/",
};

function text(value) {
  return typeof value === "string" ? value.trim() : "";
}

export function reminderPayload(entry, defaults = DEFAULT_REMINDER) {
  const fallback = {
    title: text(defaults?.title) || DEFAULT_REMINDER.title,
    body: text(defaults?.body) || DEFAULT_REMINDER.body,
    url: text(defaults?.url) || DEFAULT_REMINDER.url,
  };
  const message = entry?.message;
  if (!message || typeof message !== "object") return fallback;
  const title = text(message.title);
  const body = text(message.body);
  if (!title || !body) return fallback;
  const url = text(message.url);
  return { title, body, url: url.startsWith("/") ? url : fallback.url };
}