info_tren/lib/pages/about/about_page.dart

import 'package:flutter/widgets.dart';
import 'package:info_tren/api/releases.dart';
import 'package:info_tren/models.dart';
import 'package:info_tren/pages/about/about_page_cupertino.dart';
import 'package:info_tren/pages/about/about_page_material.dart';
import 'package:info_tren/utils/default_ui_design.dart';
import 'package:package_info_plus/package_info_plus.dart';

class AboutPage extends StatefulWidget {
  final UiDesign? uiDesign;

  const AboutPage({Key? key, this.uiDesign}) : super(key: key);

  static String routeName = '/about';
  
  @override
  State<StatefulWidget> createState() {
    final uiDesign = this.uiDesign ?? defaultUiDesign;
    
    switch (uiDesign) {
      case UiDesign.MATERIAL:
        return AboutPageStateMaterial();
      case UiDesign.CUPERTINO:
        return AboutPageStateCupertino();
      default:
        throw UnmatchedUiDesignException(uiDesign);
    }
  }
}

abstract class AboutPageState extends State<AboutPage> {
  static const String DOWNLOAD = String.fromEnvironment('DOWNLOAD');

  final String pageTitle = 'Despre aplicație';
  final String versionTitleText = 'Versiunea aplicației';
  final String latestVersionText = 'Cea mai recentă versiune';
  final String currentVersionText = 'Versiunea curentă';

  List<ChangelogEntry> localChangelog = [];
  List<ChangelogEntry> remoteChangelog = [];
  List<ChangelogEntry> get mergedChangelogs {
    final logs = remoteChangelog.toList();
    final versions = logs.map((log) => log.version).toSet();
    for (final log in localChangelog) {
      if (!versions.contains(log.version)) {
        logs.add(log);
        versions.add(log.version);
      }
    }
    logs.sort((l1, l2) => l2.version.compareTo(l1.version));
    return logs;
  }

  PackageInfo? packageInfo;

  @override
  void didChangeDependencies() {
    PackageInfo.fromPlatform().then((value) => setState(() {
      packageInfo = value;
    }));

    DefaultAssetBundle.of(context).loadString('CHANGELOG.txt').then((value) {
      setState(() {
        localChangelog = ChangelogEntry.fromTextFile(value);
      });
    });

    getRemoteReleases().then((value) => setState(() {
      remoteChangelog = value;
    }));

    super.didChangeDependencies();
  }
}