twonly-app/lib/src/utils/avatars.dart

import 'dart:async';
import 'dart:convert';
import 'dart:io';
import 'dart:ui' as ui;

import 'package:flutter/services.dart';
import 'package:flutter_svg/svg.dart';
import 'package:twonly/globals.dart';
import 'package:twonly/locator.dart';
import 'package:twonly/src/utils/log.dart';

String getAvatarSvg(Uint8List avatarSvgCompressed) {
  return utf8.decode(gzip.decode(avatarSvgCompressed));
}

Future<void> createPushAvatars({int? forceForUserId}) async {
  final contacts = await twonlyDB.contactsDao.getAllContacts();

  for (final contact in contacts) {
    try {
      if (contact.avatarSvgCompressed == null) continue;

      if (forceForUserId == null) {
        if (avatarPNGFile(contact.userId).existsSync()) {
          continue; // only create the avatar in case no avatar exists yet fot this user
        }
      } else if (contact.userId != forceForUserId) {
        // only update the avatar for this specified contact
        continue;
      }

      final avatarSvg = getAvatarSvg(contact.avatarSvgCompressed!);

      final pictureInfo = await vg.loadPicture(
        SvgStringLoader(avatarSvg),
        null,
      );

      final image = await pictureInfo.picture.toImage(270, 300);

      final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
      final pngBytes = byteData!.buffer.asUint8List();

      await avatarPNGFile(contact.userId).writeAsBytes(pngBytes);
      pictureInfo.picture.dispose();
    } catch (e) {
      Log.error(e);
    }
  }
}

File avatarPNGFile(int contactId) {
  final avatarsDirectory = Directory(
    '${AppEnvironment.cacheDir}/avatars',
  );

  if (!avatarsDirectory.existsSync()) {
    avatarsDirectory.createSync(recursive: true);
  }
  return File('${avatarsDirectory.path}/$contactId.png');
}

File currentUserAvatarFile(int avatarCounter) {
  final avatarsDirectory = Directory(
    '${AppEnvironment.cacheDir}/avatars',
  );

  if (!avatarsDirectory.existsSync()) {
    avatarsDirectory.createSync(recursive: true);
  }
  return File('${avatarsDirectory.path}/user_$avatarCounter.png');
}

Future<String?> getUserAvatar() async {
  if (userService.currentUser.avatarSvg == null) {
    return null;
  }

  final avatarCounter = userService.currentUser.avatarCounter;
  final file = currentUserAvatarFile(avatarCounter);
  if (file.existsSync()) {
    return file.path;
  }

  final pictureInfo = await vg.loadPicture(
    SvgStringLoader(userService.currentUser.avatarSvg!),
    null,
  );

  final image = await pictureInfo.picture.toImage(270, 300);

  final byteData = await image.toByteData(format: ui.ImageByteFormat.png);
  final pngBytes = byteData!.buffer.asUint8List();

  await file.writeAsBytes(pngBytes);
  pictureInfo.picture.dispose();

  return file.path;
}