/**
 * Per-page view-state persistence — survives navigation within the app.
 * Exposed as window.ViewState. No modules, no deps.
 *
 * Each page stores its last-loaded inputs + data under
 * localStorage["optionsPricer:view:<page>"] so navigating away and back
 * restores the page exactly as it was.
 */
(function () {
  "use strict";
  const PREFIX = "optionsPricer:view:";
  window.ViewState = {
    PREFIX,
    load(page) {
      try {
        const raw = localStorage.getItem(PREFIX + page);
        return raw ? JSON.parse(raw) : null;
      } catch { return null; }
    },
    save(page, data) {
      try { localStorage.setItem(PREFIX + page, JSON.stringify(data)); }
      catch (e) { console.warn("[ViewState] save failed:", e); }
    },
    clear(page) {
      try { localStorage.removeItem(PREFIX + page); } catch {}
    },
  };
})();