import {describe, it, expect, beforeEach} from 'vitest';
import {Instant} from '@/';
import {TimeZone} from '@clarify/zone-data';
import importer from '@clarify/zone-data/importer';

describe('TimeZone', () => {
  let timeZone!: TimeZone;

  beforeEach(async () => {
    timeZone = await importer['Europe/Paris']();
  });

  describe('#getTimeZoneTransition', () => {
    it('with string as option', async () => {
      let now = Instant.from('2025-03-20T00:36:00Z').toZonedDateTimeISO(timeZone);

      let next = timeZone.getTimeZoneTransition(now.epochMilliseconds, 'next')!;
      let nextDate = Instant.fromEpochMilliseconds(next).toZonedDateTimeISO(timeZone);
      expect(nextDate.toString()).toEqual('2025-03-30T03:00:00.000+02:00[Europe/Paris]');

      let previous = timeZone.getTimeZoneTransition(now.epochMilliseconds, 'previous')!;
      let previousDate = Instant.fromEpochMilliseconds(previous).toZonedDateTimeISO(timeZone);
      expect(previousDate.toString()).toEqual('2024-10-27T02:00:00.000+01:00[Europe/Paris]');

      let nextAfter = timeZone.getTimeZoneTransition(nextDate.epochMilliseconds, 'next');
      let previousAfter = timeZone.getTimeZoneTransition(previousDate.epochMilliseconds, 'previous');

      let nextAfterDate = Instant.fromEpochMilliseconds(nextAfter!).toZonedDateTimeISO(timeZone);
      let previousAfterDate = Instant.fromEpochMilliseconds(previousAfter!).toZonedDateTimeISO(timeZone);

      expect(nextAfterDate.toString()).toEqual('2025-10-26T02:00:00.000+01:00[Europe/Paris]');
      expect(previousAfterDate.toString()).toEqual('2024-03-31T03:00:00.000+02:00[Europe/Paris]');
    });
  });
});