import { addLogEntry } from "./logEntries";

const MAX_NOTIFICATION_QUERY_LENGTH = 100;

export const REQUEST_PERMISSION_TIMEOUT_MS = 8000;

/**
 * Requests permission to show browser notifications. Some browsers can
 * silently never resolve this request (e.g. Brave has been observed doing
 * this on localhost), so it falls back to "default" after a timeout instead
 * of leaving the caller waiting forever.
 */
export async function requestNotificationPermission(): Promise<NotificationPermission> {
  if (!("Notification" in window)) {
    return "denied";
  }

  if (Notification.permission === "granted") {
    return "granted";
  }

  if (Notification.permission === "denied") {
    return "denied";
  }

  return new Promise((resolve) => {
    const timeoutId = setTimeout(
      () => resolve("default"),
      REQUEST_PERMISSION_TIMEOUT_MS,
    );

    Notification.requestPermission().then((permission) => {
      clearTimeout(timeoutId);
      resolve(permission);
    });
  });
}

/**
 * Shows a browser notification that the AI answer is ready, unless this page
 * already has the focus.
 */
export function showAiCompleteNotification(query: string) {
  if (!("Notification" in window)) {
    return;
  }

  if (Notification.permission !== "granted") {
    return;
  }

  if (document.hasFocus()) {
    return;
  }

  const truncatedQuery =
    query.length > MAX_NOTIFICATION_QUERY_LENGTH
      ? `${query.slice(0, MAX_NOTIFICATION_QUERY_LENGTH)}…`
      : query;

  try {
    const notification = new Notification(truncatedQuery, {
      body: "AI response is ready on MiniSearch.",
      icon: "/favicon.png",
      tag: "ai-complete",
      requireInteraction: false,
    });
    notification.onclick = () => {
      window.focus();
      notification.close();
    };
  } catch (error) {
    addLogEntry(
      `Failed to show AI-complete notification: ${error instanceof Error ? error.message : String(error)}`,
    );
  }
}