import 'package:cookit/src/planning/day.dart';
import 'package:cookit/src/planning/day_format.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:intl/date_symbol_data_local.dart';

void main() {
  setUpAll(() => initializeDateFormatting('de'));

  final friday = DateTime.utc(2026, 10, 23);

  test('weekStartOf honours the configured first weekday', () {
    expect(weekStartOf(friday, DateTime.monday), DateTime.utc(2026, 10, 19));
    expect(weekStartOf(friday, DateTime.tuesday), DateTime.utc(2026, 10, 20));
    expect(weekStartOf(friday, DateTime.friday), friday);
    expect(weekStartOf(friday, DateTime.saturday), DateTime.utc(2026, 10, 17));
  });

  test('days survive daylight saving time and storage', () {
    // Summer time ends in Germany on 25 Oct 2026.
    expect(addDays(DateTime.utc(2026, 10, 24), 2), DateTime.utc(2026, 10, 26));
    expect(weekDays(DateTime.utc(2026, 10, 26)).last, DateTime.utc(2026, 11, 1));
    expect(dayKey(friday), '2026-10-23');
    expect(parseDayKey('2026-10-23'), friday);
    expect(dayOf(DateTime(2026, 10, 23, 23, 59)), friday);
  });

  test('calendarWeek is the ISO week, also across the turn of the year', () {
    expect(calendarWeek(DateTime.utc(2026, 10, 19)), 43);
    expect(calendarWeek(DateTime.utc(2026, 10, 20)), 43); // a Tuesday-start week
    expect(calendarWeek(DateTime.utc(2026, 12, 28)), 53);
    expect(calendarWeek(DateTime.utc(2027, 1, 4)), 1);
  });

  test('dayRange', () {
    expect(dayRange(DateTime.utc(2026, 10, 19), DateTime.utc(2026, 10, 25)), '19.–25. Okt.');
    expect(dayRange(DateTime.utc(2026, 10, 26), DateTime.utc(2026, 11, 1)), '26. Okt. – 1. Nov.');
  });
}