import 'package:flutter_test/flutter_test.dart';
import 'package:marianum_mobile/utils/recurrence_occurrences.dart';

void main() {
  setUp(RecurrenceOccurrences.clear);

  final anchor = DateTime.utc(2024, 9, 2, 8);

  test('returns only occurrences inside the half-open range', () {
    final hits = RecurrenceOccurrences.between(
      'RRULE:FREQ=DAILY',
      anchor,
      DateTime.utc(2026, 9, 21),
      DateTime.utc(2026, 9, 24),
    );
    expect(hits, [
      DateTime.utc(2026, 9, 21, 8),
      DateTime.utc(2026, 9, 22, 8),
      DateTime.utc(2026, 9, 23, 8),
    ]);
  });

  test('answers earlier ranges after a later one was expanded', () {
    RecurrenceOccurrences.between(
      'RRULE:FREQ=WEEKLY',
      anchor,
      DateTime.utc(2026, 1, 1),
      DateTime.utc(2026, 1, 31),
    );
    final hits = RecurrenceOccurrences.between(
      'RRULE:FREQ=WEEKLY',
      anchor,
      DateTime.utc(2024, 9, 1),
      DateTime.utc(2024, 9, 10),
    );
    expect(hits, [DateTime.utc(2024, 9, 2, 8), DateTime.utc(2024, 9, 9, 8)]);
  });

  test('stops at the end of a finite series', () {
    final hits = RecurrenceOccurrences.between(
      'RRULE:FREQ=DAILY;COUNT=2',
      anchor,
      DateTime.utc(2024, 1, 1),
      DateTime.utc(2030, 1, 1),
    );
    expect(hits, hasLength(2));
  });
}