/**
 * Task CAD-12a - Autosave-Service.
 *
 * Der Yjs-CRDT speichert bereits automatisch ueber WebSocket.
 * Dieser Service macht das SICHTBAR und ergaenzt:
 * - Save-Status-Text (Automatisch gespeichert / Offline / Speichert...)
 * - Periodischer Full-Save in SQLite (Redundanz)
 * - Reconnect-Handling (CRDT synced automatisch nach)
 */
import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import {
  createAutosaveController,
  type AutosaveStatus,
  AUTOSAVE_INTERVAL_MS,
} from '../src/services/autosaveService';

describe('CAD-12a: autosaveService', () => {
  beforeEach(() => {
    vi.useFakeTimers();
  });
  afterEach(() => {
    vi.useRealTimers();
  });

  it('AUTOSAVE_INTERVAL_MS ist 30 Sekunden', () => {
    expect(AUTOSAVE_INTERVAL_MS).toBe(30000);
  });

  it('Controller: Status ist "idle" wenn kein CRDT verbunden', () => {
    const ctrl = createAutosaveController({
      isConnected: () => false,
      hasUnsavedChanges: () => false,
      performFullSave: vi.fn(),
      onStatusChange: vi.fn(),
    });
    const status: AutosaveStatus = ctrl.getStatus();
    expect(status.state).toBe('offline');
    ctrl.destroy();
  });

  it('Controller: Status ist "saved" wenn CRDT verbunden und keine ungespeicherten Aenderungen', () => {
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => false,
      performFullSave: vi.fn(),
      onStatusChange: vi.fn(),
    });
    expect(ctrl.getStatus().state).toBe('saved');
    ctrl.destroy();
  });

  it('Controller: Status wechselt zu "saving" wenn Aenderungen vorhanden und Timer feuert', () => {
    const fullSave = vi.fn().mockResolvedValue(undefined);
    const onStatus = vi.fn();
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => true,
      performFullSave: fullSave,
      onStatusChange: onStatus,
    });
    vi.advanceTimersByTime(31000);
    expect(fullSave).toHaveBeenCalledTimes(1);
    ctrl.destroy();
  });

  it('Controller: fuehrt KEINEN Full-Save aus wenn keine Aenderungen', () => {
    const fullSave = vi.fn();
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => false,
      performFullSave: fullSave,
      onStatusChange: vi.fn(),
    });
    vi.advanceTimersByTime(31000);
    expect(fullSave).not.toHaveBeenCalled();
    ctrl.destroy();
  });

  it('Controller: fuehrt KEINEN Full-Save aus wenn CRDT offline', () => {
    const fullSave = vi.fn();
    const ctrl = createAutosaveController({
      isConnected: () => false,
      hasUnsavedChanges: () => true,
      performFullSave: fullSave,
      onStatusChange: vi.fn(),
    });
    vi.advanceTimersByTime(31000);
    expect(fullSave).not.toHaveBeenCalled();
    ctrl.destroy();
  });

  it('Controller: Status-Meldung an onStatusChange bei Aenderung', () => {
    const onStatus = vi.fn();
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => false,
      performFullSave: vi.fn(),
      onStatusChange: onStatus,
    });
    expect(onStatus).toHaveBeenCalledWith({ state: 'saved', lastSaved: null });
    ctrl.destroy();
  });

  it('Controller: markChanges triggert saving beim naechsten Timer-Tick', () => {
    const fullSave = vi.fn().mockResolvedValue(undefined);
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => false,
      performFullSave: fullSave,
      onStatusChange: vi.fn(),
    });
    ctrl.markChanges();
    vi.advanceTimersByTime(31000);
    expect(fullSave).toHaveBeenCalled();
    ctrl.destroy();
  });

  it('Controller: destroy stoppt den Timer', () => {
    const fullSave = vi.fn();
    const ctrl = createAutosaveController({
      isConnected: () => true,
      hasUnsavedChanges: () => true,
      performFullSave: fullSave,
      onStatusChange: vi.fn(),
    });
    ctrl.destroy();
    vi.advanceTimersByTime(60000);
    expect(fullSave).not.toHaveBeenCalled();
  });
});