Solian/lib/widgets/markdown_text_content.dart

import 'dart:ui';

import 'package:flutter/material.dart';
import 'package:flutter_markdown/flutter_markdown.dart';
import 'package:gap/gap.dart';
import 'package:get/get.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:markdown/markdown.dart' as markdown;
import 'package:path/path.dart';
import 'package:solian/providers/stickers.dart';
import 'package:solian/widgets/attachments/attachment_list.dart';
import 'package:solian/widgets/auto_cache_image.dart';
import 'package:syntax_highlight/syntax_highlight.dart';
import 'package:url_launcher/url_launcher_string.dart';

import 'account/account_profile_popup.dart';

class MarkdownTextContent extends StatelessWidget {
  final String content;
  final String parentId;
  final bool isSelectable;
  final bool isLargeText;
  final bool isAutoWarp;

  const MarkdownTextContent({
    super.key,
    required this.content,
    required this.parentId,
    this.isSelectable = false,
    this.isLargeText = false,
    this.isAutoWarp = false,
  });

  Widget _buildContent(BuildContext context) {
    final stickerRegex = RegExp(r':([-\w]+):');

    // Split the content into paragraphs
    final paragraphs = content.split(RegExp(r'\n\s*\n'));

    // Iterate over each paragraph to process stickers individually
    List<Widget> contentWidgets = [];
    for (var idx = 0; idx < paragraphs.length; idx++) {
      // Getting paragraph
      var paragraph = paragraphs[idx];

      // Matching stickers
      final stickerMatch = stickerRegex.allMatches(paragraph);
      final isOnlySticker =
          paragraph.replaceAll(stickerRegex, '').trim().isEmpty;

      contentWidgets.add(
        Markdown(
          shrinkWrap: true,
          physics: const NeverScrollableScrollPhysics(),
          data: paragraph,
          padding: EdgeInsets.zero,
          styleSheet: MarkdownStyleSheet.fromTheme(
            Theme.of(context),
          ).copyWith(
              textScaler: TextScaler.linear(isLargeText ? 1.1 : 1),
              blockquote: TextStyle(
                color: Theme.of(context).colorScheme.onSurfaceVariant,
              ),
              blockquoteDecoration: BoxDecoration(
                color: Theme.of(context).colorScheme.surfaceContainerHigh,
                borderRadius: const BorderRadius.all(Radius.circular(4)),
              ),
              horizontalRuleDecoration: BoxDecoration(
                border: Border(
                  top: BorderSide(
                    width: 1.0,
                    color: Theme.of(context).dividerColor,
                  ),
                ),
              ),
              codeblockDecoration: BoxDecoration(
                border: Border.all(
                  color: Theme.of(context).dividerColor,
                  width: 0.3,
                ),
                borderRadius: const BorderRadius.all(Radius.circular(4)),
                color: Theme.of(context).colorScheme.surface.withOpacity(0.5),
              )),
          builders: {
            'code': _MarkdownTextCodeElement(),
          },
          softLineBreak: true,
          extensionSet: markdown.ExtensionSet(
            <markdown.BlockSyntax>[
              markdown.CodeBlockSyntax(),
              ...markdown.ExtensionSet.commonMark.blockSyntaxes,
              ...markdown.ExtensionSet.gitHubFlavored.blockSyntaxes,
            ],
            <markdown.InlineSyntax>[
              if (isAutoWarp) markdown.LineBreakSyntax(),
              _UserNameCardInlineSyntax(),
              _CustomEmoteInlineSyntax(),
              markdown.AutolinkSyntax(),
              markdown.AutolinkExtensionSyntax(),
              markdown.CodeSyntax(),
              ...markdown.ExtensionSet.commonMark.inlineSyntaxes,
              ...markdown.ExtensionSet.gitHubFlavored.inlineSyntaxes
            ],
          ),
          onTapLink: (text, href, title) async {
            if (href == null) return;
            if (href.startsWith('solink://')) {
              final segments = href.replaceFirst('solink://', '').split('/');
              switch (segments[0]) {
                case 'users':
                  showModalBottomSheet(
                    useRootNavigator: true,
                    isScrollControlled: true,
                    backgroundColor: Theme.of(context).colorScheme.surface,
                    context: context,
                    builder: (context) => AccountProfilePopup(
                      name: segments[1],
                    ),
                  );
              }
              return;
            }

            await launchUrlString(
              href,
              mode: LaunchMode.externalApplication,
            );
          },
          imageBuilder: (uri, title, alt) {
            var url = uri.toString();
            double? width, height;
            BoxFit? fit;
            if (url.startsWith('solink://')) {
              final segments = url.replaceFirst('solink://', '').split('/');
              switch (segments[0]) {
                case 'stickers':
                  double radius = 8;
                  final StickerProvider sticker = Get.find();

                  // Adjust sticker size based on the sticker count in this paragraph
                  if (stickerMatch.length <= 1 && isOnlySticker) {
                    width = 128;
                    height = 128;
                  } else if (stickerMatch.length <= 3 && isOnlySticker) {
                    width = 32;
                    height = 32;
                  } else {
                    radius = 4;
                    width = 16;
                    height = 16;
                  }
                  fit = BoxFit.contain;
                  return ClipRRect(
                    borderRadius: BorderRadius.all(Radius.circular(radius)),
                    child: Container(
                      width: width,
                      height: height,
                      color: Theme.of(context).colorScheme.surfaceContainer,
                      child: FutureBuilder(
                        future: sticker.getStickerByAlias(segments[1]),
                        builder: (context, snapshot) {
                          if (!snapshot.hasData) {
                            return const Center(
                                child: CircularProgressIndicator());
                          }
                          return AutoCacheImage(
                            snapshot.data!.imageUrl,
                            width: width,
                            height: height,
                            fit: fit,
                            noErrorWidget: true,
                          );
                        },
                      ),
                    ),
                  ).paddingSymmetric(vertical: 4);
                case 'attachments':
                  const radius = BorderRadius.all(Radius.circular(8));
                  return LimitedBox(
                    maxHeight: MediaQuery.of(context).size.width,
                    child: ClipRRect(
                      borderRadius: radius,
                      child: AttachmentSelfContainedEntry(
                        isDense: true,
                        parentId: parentId,
                        rid: segments[1],
                      ),
                    ),
                  ).paddingSymmetric(vertical: 4);
              }
            }
            return AutoCacheImage(
              url,
              width: width,
              height: height,
              fit: fit,
            );
          },
        ),
      );

      if (idx < paragraphs.length - 1) {
        contentWidgets.add(isAutoWarp ? const Gap(4) : const Gap(8));
      }
    }

    // Return the list of widgets for the paragraphs
    return Column(
      mainAxisSize: MainAxisSize.min,
      crossAxisAlignment: CrossAxisAlignment.start,
      children: contentWidgets,
    );
  }

  @override
  Widget build(BuildContext context) {
    if (isSelectable) {
      return SelectionArea(child: _buildContent(context));
    }
    return _buildContent(context);
  }
}

class _UserNameCardInlineSyntax extends markdown.InlineSyntax {
  _UserNameCardInlineSyntax() : super(r'@[a-zA-Z0-9_]+');

  @override
  bool onMatch(markdown.InlineParser parser, Match match) {
    final alias = match[0]!;
    final anchor = markdown.Element.text('a', alias)
      ..attributes['href'] = Uri.encodeFull(
        'solink://users/${alias.substring(1)}',
      );
    parser.addNode(anchor);

    return true;
  }
}

class _CustomEmoteInlineSyntax extends markdown.InlineSyntax {
  _CustomEmoteInlineSyntax() : super(r':([-\w]+):');

  @override
  bool onMatch(markdown.InlineParser parser, Match match) {
    final StickerProvider sticker = Get.find();
    final alias = match[1]!.toUpperCase();
    if (sticker.stickerCache.containsKey(alias) &&
        sticker.stickerCache[alias] == null) {
      parser.advanceBy(1);
      return false;
    }

    final element = markdown.Element.empty('img');
    element.attributes['src'] = 'solink://stickers/$alias';
    parser.addNode(element);

    return true;
  }
}

class _MarkdownTextCodeElement extends MarkdownElementBuilder {
  @override
  Widget? visitElementAfter(
    markdown.Element element,
    TextStyle? preferredStyle,
  ) {
    var language = '';

    if (element.attributes['class'] != null) {
      String lg = element.attributes['class'] as String;
      language = lg.substring(9).trim();
    }
    return SizedBox(
      child: FutureBuilder(
        future: (() async {
          final docPath = '../../../';
          final highlightingPath =
              join(docPath, 'assets/highlighting', language);
          await Highlighter.initialize([highlightingPath]);
          return Highlighter(
            language: highlightingPath,
            theme: PlatformDispatcher.instance.platformBrightness ==
                    Brightness.light
                ? await HighlighterTheme.loadLightTheme()
                : await HighlighterTheme.loadDarkTheme(),
          );
        })(),
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            final highlighter = snapshot.data!;
            return Text.rich(
              highlighter.highlight(element.textContent.trim()),
              style: GoogleFonts.robotoMono(),
            );
          }
          return Text(
            element.textContent.trim(),
            style: GoogleFonts.robotoMono(),
          );
        },
      ),
    ).paddingAll(8);
  }
}