export const selectedAppStorageKey = 'studio-admin:selected-app-id';
export const selectedComponentByAppStorageKey = 'studio-admin:selected-component-by-app-id';
export const selectedComponentChangedEventName = 'studio-admin:selected-component-change';
const legacySelectedAppStorageKey = 'studio-selected-app-id';

export function getStoredSelectedAppId() {
  const current = window.localStorage.getItem(selectedAppStorageKey);
  if (current) return current;

  const legacy = window.localStorage.getItem(legacySelectedAppStorageKey);
  if (legacy) {
    setStoredSelectedAppId(legacy);
    window.localStorage.removeItem(legacySelectedAppStorageKey);
    return legacy;
  }

  return '';
}

export function setStoredSelectedAppId(appId: string) {
  if (!appId) return;
  window.localStorage.setItem(selectedAppStorageKey, appId);
}

function readSelectedComponentMap(): Record<string, string> {
  const raw = window.localStorage.getItem(selectedComponentByAppStorageKey);
  if (!raw) return {};

  try {
    const parsed = JSON.parse(raw) as unknown;
    if (!parsed || typeof parsed !== 'object' || Array.isArray(parsed)) return {};
    return Object.fromEntries(
      Object.entries(parsed)
        .filter((entry): entry is [string, string] => typeof entry[0] === 'string' && typeof entry[1] === 'string')
    );
  } catch {
    return {};
  }
}

export function getStoredSelectedComponentId(appId: string) {
  if (!appId) return '';
  return readSelectedComponentMap()[appId] ?? '';
}

export function setStoredSelectedComponentId(appId: string, componentId: string) {
  if (!appId || !componentId) return;
  window.localStorage.setItem(selectedComponentByAppStorageKey, JSON.stringify({
    ...readSelectedComponentMap(),
    [appId]: componentId,
  }));
  window.dispatchEvent(new CustomEvent(selectedComponentChangedEventName, {
    detail: { appId, componentId },
  }));
}