zap-stream-flutter/lib/widgets/nostr_text.dart

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_markdown_plus/flutter_markdown_plus.dart';
import 'package:go_router/go_router.dart';
import 'package:ndk/ndk.dart';
import 'package:ndk/shared/nips/nip19/nip19.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:zap_stream_flutter/imgproxy.dart';
import 'package:zap_stream_flutter/theme.dart';
import 'package:zap_stream_flutter/utils.dart';
import 'package:zap_stream_flutter/widgets/custom_emoji.dart';
import 'package:zap_stream_flutter/widgets/note_embed.dart';
import 'package:zap_stream_flutter/widgets/profile.dart';
import 'package:zap_stream_flutter/widgets/video_player.dart';

class NoteText extends StatelessWidget {
  final Nip01Event event;
  final bool? embedMedia;
  final bool? showEmbeds;

  const NoteText({
    super.key,
    required this.event,
    this.embedMedia,
    this.showEmbeds,
  });

  @override
  Widget build(BuildContext context) {
    // use markdown rendering for articles
    if (event.kind == 30_023) {
      return MarkdownBody(data: event.content);
    }
    return RichText(
      text: TextSpan(
        children: textToSpans(
          event.content,
          event.tags,
          event.pubKey,
          showEmbeds: showEmbeds,
          embedMedia: embedMedia,
        ),
      ),
    );
  }
}

/// Converts a nostr note text containing links
/// and mentions into multiple spans for rendering
/// /// https://github.com/leo-lox/camelus/blob/f58455a0ac07fcc780bdc69b8f4544fd5ea4a46d/lib/presentation_layer/components/note_card/note_card_build_split_content.dart#L262
List<InlineSpan> textToSpans(
  String content,
  List<List<String>> tags,
  String pubkey, {
  bool? showEmbeds,
  bool? embedMedia,
}) {
  List<InlineSpan> spans = [];
  RegExp exp = RegExp(
    r'nostr:(nprofile|npub)[a-zA-Z0-9]+|'
    r'nostr:(note|nevent|naddr)[a-zA-Z0-9]+|'
    r'(#\$\$\s*[0-9]+\s*\$\$)|'
    r'(#\w+)|' // Hashtags
    r'(https?:\/\/(?:www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,10}\b(?:[-a-zA-Z0-9()@:%_\+.~#?&\/=]*))', // URLs
    caseSensitive: false,
  );

  content.splitMapJoin(
    exp,
    onMatch: (Match match) {
      String? matched = match.group(0);
      if (matched != null) {
        if (matched.startsWith('nostr:')) {
          spans.add(_buildProfileOrNoteSpan(matched, showEmbeds ?? true));
        } else if (matched.startsWith('#')) {
          spans.add(_buildHashtagSpan(matched));
        } else if (matched.startsWith('http')) {
          spans.add(_buildUrlSpan(matched, embedMedia ?? false));
        }
      }
      return '';
    },
    onNonMatch: (String text) {
      final textTrim = text.trim();
      if (textTrim.startsWith(":") &&
          textTrim.endsWith(":") &&
          tags.any(
            (t) =>
                t[0] == "emoji" &&
                t[1] == textTrim.substring(1, textTrim.length - 1),
          )) {
        spans.add(
          WidgetSpan(
            alignment: PlaceholderAlignment.middle,
            child: CustomEmoji(emoji: textTrim, tags: tags, size: 24),
          ),
        );
      } else {
        spans.add(TextSpan(text: text));
      }
      return '';
    },
  );

  return spans;
}

InlineSpan _buildProfileOrNoteSpan(String word, bool showEmbeds) {
  final cleanedWord = word.replaceAll('nostr:', '');
  final isProfile =
      cleanedWord.startsWith('nprofile') || cleanedWord.startsWith('npub');
  final isNote =
      cleanedWord.startsWith('note') ||
      cleanedWord.startsWith('nevent') ||
      cleanedWord.startsWith("naddr");

  if (isProfile) {
    final hexKey = bech32ToHex(cleanedWord);
    if (hexKey.isNotEmpty) {
      return _inlineMention(hexKey);
    } else {
      return TextSpan(text: "@$cleanedWord");
    }
  }
  if (isNote && showEmbeds) {
    return WidgetSpan(
      child: NoteEmbedWidget(link: cleanedWord),
      alignment: PlaceholderAlignment.middle,
    );
  } else {
    return TextSpan(text: word, style: TextStyle(color: PRIMARY_1));
  }
}

InlineSpan _buildHashtagSpan(String word) {
  return TextSpan(text: word, style: TextStyle(color: PRIMARY_1));
}

InlineSpan _buildUrlSpan(String url, bool embedMedia) {
  if (embedMedia &&
      (url.endsWith(".jpg") ||
          url.endsWith(".gif") ||
          url.endsWith(".jpeg") ||
          url.endsWith(".webp") ||
          url.endsWith(".png") ||
          url.endsWith(".bmp"))) {
    return WidgetSpan(child: ProxyImg(url: url));
  }
  if (embedMedia &&
      (url.endsWith(".mp4") ||
          url.endsWith(".mov") ||
          url.endsWith(".webm") ||
          url.endsWith(".mkv") ||
          url.endsWith(".m3u8"))) {
    return WidgetSpan(
      child: AspectRatio(
        aspectRatio: 16 / 9,
        child: Center(child: VideoPlayerWidget(url: url, autoPlay: false)),
      ),
    );
  }
  return TextSpan(
    text: url,
    style: TextStyle(color: PRIMARY_1),
    recognizer:
        TapGestureRecognizer()
          ..onTap = () {
            launchUrl(Uri.parse(url));
          },
  );
}

InlineSpan _inlineMention(String pubkey) {
  return WidgetSpan(
    alignment: PlaceholderAlignment.middle,
    child: ProfileLoaderWidget(pubkey, (ctx, profile) {
      return GestureDetector(
        onTap:
            () => ctx.push(
              "/p/${Nip19.encodePubKey(pubkey)}",
              extra: profile.data,
            ),
        child: Text(
          "@${ProfileNameWidget.nameFromProfile(profile.data ?? Metadata(pubKey: pubkey))}",
          style: TextStyle(color: PRIMARY_1),
        ),
      );
    }),
  );
}