import * as Calendar from 'expo-calendar';
import { ensureCalendarPermission, fetchNativeEvents } from '../services/calendar';

// Mock expo-calendar
jest.mock('expo-calendar', () => ({
  requestCalendarPermissionsAsync: jest.fn(),
  isAvailableAsync: jest.fn(),
  getCalendarsAsync: jest.fn(),
  getEventsAsync: jest.fn(),
  EntityTypes: {
    EVENTS: 'EVENTS',
  },
}));

const mockCalendar = Calendar as jest.Mocked<typeof Calendar>;

describe('calendar service', () => {
  beforeEach(() => {
    jest.clearAllMocks();
  });

  describe('ensureCalendarPermission', () => {
    it('returns true when permission granted and calendar available', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(true);

      const result = await ensureCalendarPermission();
      expect(result).toBe(true);
    });

    it('returns false when permission denied', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'denied' as Calendar.PermissionStatus, granted: false, expires: 'never' as const, canAskAgain: true });

      const result = await ensureCalendarPermission();
      expect(result).toBe(false);
      expect(mockCalendar.isAvailableAsync).not.toHaveBeenCalled();
    });

    it('returns false when calendar not available', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(false);

      const result = await ensureCalendarPermission();
      expect(result).toBe(false);
    });
  });

  describe('fetchNativeEvents', () => {
    it('returns empty array when no permission', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'denied' as Calendar.PermissionStatus, granted: false, expires: 'never' as const, canAskAgain: true });

      const result = await fetchNativeEvents(new Date(), new Date());
      expect(result).toEqual([]);
    });

    it('returns empty array when no calendars', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(true);
      mockCalendar.getCalendarsAsync.mockResolvedValue([]);

      const result = await fetchNativeEvents(new Date(), new Date());
      expect(result).toEqual([]);
    });

    it('returns mapped events from native calendar', async () => {
      const startDate = new Date('2025-01-01');
      const endDate = new Date('2025-01-31');

      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(true);
      mockCalendar.getCalendarsAsync.mockResolvedValue([
        { id: 'cal1', title: 'Work' },
        { id: 'cal2', title: 'Personal' },
      ] as Calendar.Calendar[]);
      mockCalendar.getEventsAsync.mockResolvedValue([
        {
          id: 'evt1',
          calendarId: 'cal1',
          title: 'Team Meeting',
          location: 'Berlin',
          startDate: new Date('2025-01-15T10:00:00'),
        },
        {
          id: 'evt2',
          calendarId: 'cal2',
          title: 'Dentist',
          location: null,
          startDate: new Date('2025-01-20T14:00:00'),
        },
      ] as Calendar.Event[]);

      const result = await fetchNativeEvents(startDate, endDate);

      // Only the event with a location is returned; events without a location are filtered out
      expect(result).toHaveLength(1);
      expect(result[0]).toEqual({
        id: 'evt1',
        title: 'Team Meeting',
        destination: 'Berlin',
        eventTime: new Date('2025-01-15T10:00:00'),
        source: 'native:cal1',
      });

      expect(mockCalendar.getEventsAsync).toHaveBeenCalledWith(
        ['cal1', 'cal2'],
        startDate,
        endDate,
      );
    });

    it('filters out events with no location', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(true);
      mockCalendar.getCalendarsAsync.mockResolvedValue([{ id: 'cal1', title: 'Default' }] as Calendar.Calendar[]);
      mockCalendar.getEventsAsync.mockResolvedValue([
        {
          id: 'evt1',
          calendarId: 'cal1',
          title: 'No Location Event',
          location: null,
          startDate: new Date('2025-01-15T10:00:00'),
        },
        {
          id: 'evt2',
          calendarId: 'cal1',
          title: 'Empty Location Event',
          location: '   ',
          startDate: new Date('2025-01-16T10:00:00'),
        },
      ] as Calendar.Event[]);

      const result = await fetchNativeEvents(new Date(), new Date());

      expect(result).toHaveLength(0);
    });

    it('handles events with missing title', async () => {
      mockCalendar.requestCalendarPermissionsAsync.mockResolvedValue({ status: 'granted' as Calendar.PermissionStatus, granted: true, expires: 'never' as const, canAskAgain: true });
      mockCalendar.isAvailableAsync.mockResolvedValue(true);
      mockCalendar.getCalendarsAsync.mockResolvedValue([{ id: 'cal1', title: 'Default' }] as Calendar.Calendar[]);
      mockCalendar.getEventsAsync.mockResolvedValue([
        {
          id: 'evt1',
          calendarId: 'cal1',
          title: null as unknown as string,
          location: 'Wien Hbf',
          startDate: null as unknown as string | Date,
        },
      ] as Calendar.Event[]);

      const result = await fetchNativeEvents(new Date(), new Date());

      expect(result).toHaveLength(1);
      expect(result[0].title).toBe('Untitled Event');
      expect(result[0].destination).toBe('Wien Hbf');
    });
  });
});