import { createDefaultWorkbenchState } from './defaultWorkspace';
import type { WorkbenchState } from './workspaceTypes';

const STORAGE_KEY = 'xslt-tools:workspace:v1';

function isWorkbenchState(value: unknown): value is WorkbenchState {
  if (!value || typeof value !== 'object') return false;

  const candidate = value as Partial<WorkbenchState>;
  return (
    candidate.schemaVersion === 1 &&
    Boolean(candidate.xmlInput) &&
    Boolean(candidate.xsltCode) &&
    Boolean(candidate.xmlOutput)
  );
}

export function loadWorkbenchState(): WorkbenchState {
  const fallback = createDefaultWorkbenchState();

  try {
    const raw = window.localStorage.getItem(STORAGE_KEY);
    if (!raw) return fallback;

    const parsed = JSON.parse(raw) as unknown;
    if (!isWorkbenchState(parsed)) return fallback;

    return {
      ...fallback,
      ...parsed,
      options: { ...fallback.options, ...parsed.options },
      xmlInput: { ...fallback.xmlInput, ...parsed.xmlInput },
      xsltCode: { ...fallback.xsltCode, ...parsed.xsltCode },
      xmlOutput: { ...fallback.xmlOutput, ...parsed.xmlOutput },
    };
  } catch (error) {
    console.warn('Failed to load workspace from LocalStorage.', error);
    return fallback;
  }
}

export function saveWorkbenchState(state: WorkbenchState): void {
  try {
    window.localStorage.setItem(STORAGE_KEY, JSON.stringify(state));
  } catch (error) {
    console.warn('Failed to save workspace to LocalStorage.', error);
  }
}

export function clearWorkbenchState(): void {
  window.localStorage.removeItem(STORAGE_KEY);
}