/// 相册时区格式化纯逻辑测试（P3 计划 Task 4）。
///
/// 覆盖：UTC 瞬间 → Asia/Shanghai 墙钟展示、无效时区回退 UTC、
/// 墙钟 → UTC 提交往返一致、IANA 时区名校验。
library;

import 'package:flutter_test/flutter_test.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:photo_live/features/albums/album_format.dart';

void main() {
  setUpAll(initializeDateFormatting);

  test('UTC 瞬间按 Asia/Shanghai 展示（intl 格式化）', () {
    final utc = DateTime.utc(2026, 9, 18, 6, 30);
    expect(formatAlbumDateTime(utc, 'Asia/Shanghai', 'en'), '2026/9/18 14:30');
  });

  test('非 Asia/Shanghai 时区亦按各自墙钟展示（America/New_York）', () {
    final utc = DateTime.utc(2026, 9, 18, 6, 30);
    // 9 月为纽约夏令时 UTC-4 → 02:30。
    expect(
      formatAlbumDateTime(utc, 'America/New_York', 'en'),
      '2026/9/18 02:30',
    );
  });

  test('无效时区回退 UTC 展示', () {
    final utc = DateTime.utc(2026, 9, 18, 6, 30);
    expect(formatAlbumDateTime(utc, 'Mars/Olympus', 'en'), '2026/9/18 06:30');
  });

  test('墙钟 → UTC 往返一致（表单提交与回显）', () {
    final naive = DateTime(2026, 9, 18, 14, 30);
    final utc = albumWallClockToUtc(naive, 'Asia/Shanghai');
    expect(utc.toUtc(), DateTime.utc(2026, 9, 18, 6, 30));
    final zoned = tryToAlbumZone(utc, 'Asia/Shanghai');
    expect(zoned, isNotNull);
    expect(zoned!.hour, 14);
    expect(zoned.minute, 30);
  });

  test('isValidTimezone：空/非法拒绝，合法通过', () {
    expect(isValidTimezone(''), isFalse);
    expect(isValidTimezone('  '), isFalse);
    expect(isValidTimezone('Not/AZone'), isFalse);
    expect(isValidTimezone('Asia/Shanghai'), isTrue);
    expect(isValidTimezone('UTC'), isTrue);
  });
}