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

void main() {
  group('standaloneEmojiFontSize', () {
    test('returns null for empty or whitespace-only text', () {
      expect(standaloneEmojiFontSize(''), isNull);
      expect(standaloneEmojiFontSize('   '), isNull);
    });

    test('returns null for plain text', () {
      expect(standaloneEmojiFontSize('Hallo'), isNull);
      expect(standaloneEmojiFontSize('ok'), isNull);
    });

    test('returns null when emoji is mixed with text', () {
      expect(standaloneEmojiFontSize('Hallo 😀'), isNull);
      expect(standaloneEmojiFontSize('😀 super'), isNull);
    });

    test('enlarges a single emoji the most', () {
      expect(standaloneEmojiFontSize('😀'), 34);
      expect(standaloneEmojiFontSize('👍'), 34);
    });

    test('enlarges up to three emojis at the largest size', () {
      expect(standaloneEmojiFontSize('😀😀😀'), 34);
      expect(standaloneEmojiFontSize('😀 😀 😀'), 34);
    });

    test('does not enlarge more than three emojis', () {
      expect(standaloneEmojiFontSize('😀😀😀😀'), isNull);
      expect(standaloneEmojiFontSize('😀😀😀😀😀😀'), isNull);
    });

    test('handles ZWJ sequences as a single emoji', () {
      // Family emoji: multiple codepoints joined via ZWJ → one cluster.
      expect(standaloneEmojiFontSize('👨‍👩‍👧‍👦'), 34);
    });

    test('handles skin-tone modified emoji as a single emoji', () {
      expect(standaloneEmojiFontSize('👍🏽'), 34);
    });

    test('handles emoji with variation selectors', () {
      expect(standaloneEmojiFontSize('❤️'), 34);
      expect(standaloneEmojiFontSize('⭐'), 34);
    });

    test('handles keycap emoji', () {
      expect(standaloneEmojiFontSize('1️⃣'), 34);
    });

    test('handles flag emoji (regional indicators)', () {
      expect(standaloneEmojiFontSize('🇩🇪'), 34);
    });

    test('bare digits without keycap are not emoji', () {
      expect(standaloneEmojiFontSize('123'), isNull);
    });
  });
}