/**
 * Per-browser tour dismissals in localStorage, keyed by tour id. Mirrors the
 * announcement dismissal store (browser storage is read during mount and
 * written during mount or the explicit dismissal handler; it is never
 * accessed during render). Dismissals are permanent per browser: a tour that
 * was dismissed never auto-starts again, but the header replay control can
 * always run it on demand.
 */

const DISMISSALS_STORAGE_KEY = "ptf:tour:dismissals";
const OPTED_OUT_STORAGE_KEY = "ptf:tours:opted-out";

export type TourDismissals = Record<string, number>;

function isRecord(value: unknown): value is Record<string, unknown> {
  return typeof value === "object" && value !== null;
}

export function readTourDismissals(now: number): TourDismissals {
  if (typeof window === "undefined") return {};

  try {
    const raw = window.localStorage.getItem(DISMISSALS_STORAGE_KEY);
    if (!raw) return {};
    const parsed: unknown = JSON.parse(raw);
    if (!isRecord(parsed)) return {};

    const dismissals: TourDismissals = {};
    for (const [key, value] of Object.entries(parsed)) {
      if (typeof value === "number" && Number.isFinite(value) && value > 0) {
        dismissals[key] = value;
      }
    }
    return dismissals;
  } catch (error) {
    if (error instanceof Error) return {};
    throw error;
  }
}

export function writeTourDismissals(dismissals: TourDismissals, now: number): void {
  if (typeof window === "undefined") return;

  try {
    window.localStorage.setItem(DISMISSALS_STORAGE_KEY, JSON.stringify(dismissals));
  } catch (error) {
    if (error instanceof Error) return;
    throw error;
  }
}

/** Merges a single dismissal (timestamp = dismissal time) into the stored map. */
export function storeTourDismissal(tourId: string, now: number): void {
  const existing = readTourDismissals(now);
  writeTourDismissals({ ...existing, [tourId]: now }, now);
}

/** True when the tour has been dismissed by this browser before `now`. */
export function isTourDismissed(tourId: string, now: number): boolean {
  return readTourDismissals(now)[tourId] !== undefined;
}

/**
 * Site-wide tours opt-out (per browser). When set, tours never auto-start;
 * the header replay control remains as the explicit opt-in.
 */
export function isToursOptedOut(): boolean {
  if (typeof window === "undefined") return false;
  try {
    return window.localStorage.getItem(OPTED_OUT_STORAGE_KEY) === "1";
  } catch (error) {
    if (error instanceof Error) return false;
    throw error;
  }
}

export function setToursOptedOut(optedOut: boolean): void {
  if (typeof window === "undefined") return;
  try {
    if (optedOut) {
      window.localStorage.setItem(OPTED_OUT_STORAGE_KEY, "1");
    } else {
      window.localStorage.removeItem(OPTED_OUT_STORAGE_KEY);
    }
  } catch (error) {
    if (error instanceof Error) return;
    throw error;
  }
}