/**
 * [Gitea #116] PWA install hint — pure decision logic.
 *
 * Chromium fires `beforeinstallprompt`; iOS Safari never prompts and only
 * installs via Share → "Add to Home Screen", so people on phones simply never
 * find it. The hint is shown once the user has come back at least once (second
 * visit), never inside the desktop app or an already-installed PWA, and snoozes
 * for 30 days after a dismissal.
 */

export const INSTALL_HINT_MIN_VISITS = 2;
export const INSTALL_HINT_SNOOZE_MS = 30 * 24 * 60 * 60 * 1000;

export type InstallHintInput = {
  /** Running inside the Tauri desktop app. */
  isTauri: boolean;
  /** `display-mode: standalone` or iOS `navigator.standalone` — already installed. */
  isStandalone: boolean;
  /** Distinct app visits recorded so far, including this one. */
  visits: number;
  /** Epoch ms of the last dismissal, or null. */
  dismissedAt: number | null;
  now: number;
};

export const shouldShowInstallHint = ({
  isTauri,
  isStandalone,
  visits,
  dismissedAt,
  now,
}: InstallHintInput): boolean => {
  if (isTauri || isStandalone) return false;
  if (visits < INSTALL_HINT_MIN_VISITS) return false;
  if (dismissedAt !== null && now - dismissedAt < INSTALL_HINT_SNOOZE_MS) return false;
  return true;
};

export type InstallHintKind = 'prompt' | 'ios-share' | 'none';

/**
 * Which hint to show: a real install prompt when the browser handed us a
 * deferred `beforeinstallprompt`, the manual Share-sheet instructions on iOS
 * Safari, or nothing (Firefox desktop and friends have no install path — a
 * hint there would just be noise).
 */
export const installHintKind = (
  hasDeferredPrompt: boolean,
  isIosSafari: boolean,
): InstallHintKind => {
  if (hasDeferredPrompt) return 'prompt';
  if (isIosSafari) return 'ios-share';
  return 'none';
};