eatvio_app/lib/features/diets/presentation/widgets/expandable_text.dart

import 'dart:math' as math;

import 'package:eatvio_app/generated/l10n.dart';
import 'package:eatvio_app/core/theme/custom_text_style.dart';
import 'package:eatvio_app/core/theme/theme_helper.dart';
import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:flutter_html/flutter_html.dart';
import 'package:markdown/markdown.dart' as md;
import 'package:url_launcher/url_launcher.dart';

class ExpandableText extends StatefulWidget {
  final String text;
  final int maxLines;

  const ExpandableText({
    super.key,
    required this.text,
    this.maxLines = 5, // по умолчанию 5 строк
  });

  @override
  State<ExpandableText> createState() => _ExpandableTextState();
}

class _ExpandableTextState extends State<ExpandableText> {
  bool isExpanded = false;
  bool showExpandButton = false;

  final GlobalKey _textKey = GlobalKey();

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    WidgetsBinding.instance.addPostFrameCallback((_) => _checkTextOverflow());
  }

  void _checkTextOverflow() {
    final textRenderObject = _textKey.currentContext?.findRenderObject();
    if (textRenderObject is RenderBox) {
      final fontSize = TextStyles.textMMediumAuto.fontSize ?? 16;
      final lineHeight = fontSize * 1.5;
      final maxLinesHeight = widget.maxLines * lineHeight;
      final actualHeight = textRenderObject.size.height;

      if (actualHeight > maxLinesHeight && !showExpandButton) {
        setState(() {
          showExpandButton = true;
        });
      }
    }
  }

  void toggleExpansion() {
    setState(() {
      isExpanded = !isExpanded;
    });
  }

  String _processMarkdown(String text) {
    // Автоматически преобразуем URL в markdown ссылки
    // Сначала исправляем неправильный синтаксис markdown ссылок
    final wrongLinkRegex = RegExp(r'\[(https?://[^\]]+|www\.[^\]]+)\]\(([^\)]+)\)');
    text = text.replaceAllMapped(wrongLinkRegex, (match) {
      final urlInText = match.group(1)!;
      if (!urlInText.startsWith('http://') && !urlInText.startsWith('https://') && !urlInText.startsWith('www.')) {
        return match.group(0)!;
      }
      final fullUrl = urlInText.startsWith('www.') ? 'https://$urlInText' : urlInText;
      return '[$urlInText]($fullUrl)';
    });
    
    final linkRegex = RegExp(r'\[([^\]]+)\]\(([^\)]+)\)');
    final existingLinks = <_LinkRange>[];
    for (final linkMatch in linkRegex.allMatches(text)) {
      existingLinks.add(_LinkRange(linkMatch.start, linkMatch.end));
    }
    final urlRegex = RegExp(r'(https?://[^\s\)]+|www\.[^\s\)]+)', caseSensitive: false);
    String result = text;
    int offset = 0;
    for (final urlMatch in urlRegex.allMatches(text)) {
      bool isInsideLink = existingLinks.any((link) =>
          urlMatch.start >= link.start && urlMatch.end <= link.end);
      if (!isInsideLink) {
        final url = urlMatch.group(0)!;
        final fullUrl = url.startsWith('www.') ? 'https://$url' : url;
        final replacement = '[$url]($fullUrl)';
        result = result.replaceRange(
          urlMatch.start + offset,
          urlMatch.end + offset,
          replacement,
        );
        offset += replacement.length - url.length;
      }
    }

    // Гарантируем, что жирный текст будет распознан
    final boldRegex = RegExp(r'\*\*([^*]+)\*\*');
    result = result.replaceAllMapped(boldRegex, (match) {
      return '<b>${match.group(1)}</b>';
    });

    return result;
  }

  @override
  Widget build(BuildContext context) {
    final s = S.of(context);
    final processedText = _processMarkdown(widget.text);
    final htmlData = md.markdownToHtml(
      processedText,
      extensionSet: md.ExtensionSet.gitHubFlavored,
    );
    
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16),
          child: AnimatedSize(
            duration: const Duration(milliseconds: 200),
            curve: Curves.easeInOut,
            child: Stack(
              children: [
                ClipRect(
                  child: ConstrainedBox(
                    constraints: BoxConstraints(
                      maxHeight: isExpanded ? double.infinity : (widget.maxLines * (TextStyles.textMMediumAuto.fontSize ?? 16) * 1.5),
                    ),
                    child: Html(
                      key: _textKey,
                      data: htmlData,
                      style: {
                        "body": Style(
                          margin: Margins.zero,
                          padding: HtmlPaddings.zero,
                          fontSize: FontSize(TextStyles.textMMediumAuto.fontSize ?? 16),
                          lineHeight: const LineHeight(1.5),
                        ),
                        "p": Style(margin: Margins.only(bottom: 12), color: appTheme.black),
                        "b, strong": Style(fontWeight: FontWeight.bold, color: appTheme.black),
                        "h1, h2, h3, h4, h5, h6": Style(margin: Margins.only(top: 16, bottom: 8), color: appTheme.black, fontWeight: FontWeight.bold),
                        "h1": Style(fontSize: FontSize(24)),
                        "h2": Style(fontSize: FontSize(20)),
                        "h3": Style(fontSize: FontSize(18)),
                        "ul, ol": Style(margin: Margins.only(bottom: 12), padding: HtmlPaddings.only(left: 16)),
                        "li": Style(margin: Margins.only(bottom: 4), color: appTheme.black),
                        "strong, b": Style(fontWeight: FontWeight.bold, color: appTheme.black),
                        "em, i": Style(fontStyle: FontStyle.italic),
                        "code": Style(
                          backgroundColor: Colors.grey.shade100,
                          padding: HtmlPaddings.symmetric(horizontal: 4, vertical: 2),
                          fontFamily: 'monospace',
                        ),
                        "pre": Style(backgroundColor: Colors.grey.shade100, padding: HtmlPaddings.all(12), margin: Margins.only(bottom: 12)),
                        "blockquote": Style(
                          padding: HtmlPaddings.only(left: 16),
                          margin: Margins.only(left: 8, bottom: 12),
                          fontStyle: FontStyle.italic,
                          color: Colors.grey.shade700,
                        ),
                        "a": Style(color: Colors.blue, textDecoration: TextDecoration.underline),
                        "img": Style(width: Width(MediaQuery.of(context).size.width - 32)),
                      },
                      onLinkTap: (url, attributes, element) async {
                        if (url != null) {
                          final uri = Uri.parse(url);
                          if (await canLaunchUrl(uri)) {
                            await launchUrl(uri, mode: LaunchMode.externalApplication);
                          }
                        }
                      },
                    ),
                  ),
                ),
                if (!isExpanded && showExpandButton)
                  Positioned.fill(
                    child: Align(
                      alignment: Alignment.bottomCenter,
                      child: Container(
                        height: 35,
                        decoration: BoxDecoration(
                          gradient: LinearGradient(
                            begin: Alignment.topCenter,
                            end: Alignment.bottomCenter,
                            colors: [
                              Colors.white.withAlpha(0),
                              Colors.white.withAlpha((255 * 0.6).toInt()),
                              Colors.white,
                            ],
                          ),
                        ),
                      ),
                    ),
                  ),
              ],
            ),
          ),
        ),
        if (showExpandButton)
          Align(
            alignment: Alignment.bottomCenter,
            child: GestureDetector(
              onTap: toggleExpansion,
              child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text(
                    isExpanded ? s.hide : s.expand,
                    style: TextStyles.textMMedium.copyWith(color: appTheme.blueA400),
                  ),
                  const SizedBox(width: 4),
                  Transform.rotate(
                    angle: isExpanded ? math.pi : 0,
                    child: SvgPicture.asset('assets/icons/arrow_down.svg', width: 12, height: 12),
                  ),
                ],
              ),
            ),
          ),
      ],
    );
  }
}

class _LinkRange {
  final int start;
  final int end;
  _LinkRange(this.start, this.end);
}