plezy/lib/screens/settings/licenses_screen.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:plezy/widgets/app_icon.dart';
import 'package:material_symbols_icons/symbols.dart';
import '../../widgets/focused_scroll_scaffold.dart';
import '../../i18n/strings.g.dart';

class MergedLicenseEntry {
  final String packageName;
  final List<LicenseEntry> licenseEntries;
  final Set<String> allPackageNames;

  MergedLicenseEntry({
    required this.packageName,
    required this.licenseEntries,
    required this.allPackageNames,
  });
}

class LicensesScreen extends StatefulWidget {
  const LicensesScreen({super.key});

  @override
  State<LicensesScreen> createState() => _LicensesScreenState();
}

class _LicensesScreenState extends State<LicensesScreen> {
  List<MergedLicenseEntry> _mergedLicenses = [];
  bool _isLoading = true;

  @override
  void initState() {
    super.initState();
    _loadLicenses();
  }

  Future<void> _loadLicenses() async {
    final licenseMap = <String, List<LicenseEntry>>{};
    final allPackageNames = <String, Set<String>>{};

    await for (final license in LicenseRegistry.licenses) {
      for (final packageName in license.packages) {
        if (!licenseMap.containsKey(packageName)) {
          licenseMap[packageName] = [];
          allPackageNames[packageName] = <String>{};
        }
        licenseMap[packageName]!.add(license);
        allPackageNames[packageName]!.addAll(license.packages);
      }
    }

    final mergedLicenses = licenseMap.entries.map((entry) {
      return MergedLicenseEntry(
        packageName: entry.key,
        licenseEntries: entry.value,
        allPackageNames: allPackageNames[entry.key]!,
      );
    }).toList();

    mergedLicenses.sort((a, b) => a.packageName.compareTo(b.packageName));

    if (mounted) {
      setState(() {
        _mergedLicenses = mergedLicenses;
        _isLoading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    if (_isLoading) {
      return FocusedScrollScaffold(
        title: Text(t.screens.licenses),
        slivers: const [
          SliverFillRemaining(
            child: Center(child: CircularProgressIndicator()),
          ),
        ],
      );
    }

    return FocusedScrollScaffold(
      title: Text(t.screens.licenses),
      slivers: [
        SliverPadding(
          padding: const EdgeInsets.all(16),
          sliver: SliverList(
            delegate: SliverChildBuilderDelegate((context, index) {
              final mergedLicense = _mergedLicenses[index];
              final packageName = mergedLicense.packageName;

              return Card(
                margin: const EdgeInsets.only(bottom: 8),
                child: ListTile(
                  title: Text(
                    packageName,
                    style: Theme.of(context).textTheme.titleMedium?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
                  ),
                  subtitle: mergedLicense.licenseEntries.length > 1
                      ? Text(
                          t.licenses.licensesCount(
                            count: mergedLicense.licenseEntries.length,
                          ),
                        )
                      : null,
                  trailing: const AppIcon(Symbols.chevron_right_rounded, fill: 1),
                  onTap: () => _showLicenseDetail(mergedLicense),
                ),
              );
            }, childCount: _mergedLicenses.length),
          ),
        ),
      ],
    );
  }

  void _showLicenseDetail(MergedLicenseEntry mergedLicense) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) =>
            _LicenseDetailScreen(mergedLicense: mergedLicense),
      ),
    );
  }
}

class _LicenseDetailScreen extends StatelessWidget {
  final MergedLicenseEntry mergedLicense;

  const _LicenseDetailScreen({required this.mergedLicense});

  @override
  Widget build(BuildContext context) {
    final packageName = mergedLicense.packageName;
    final licenseEntries = mergedLicense.licenseEntries;

    return FocusedScrollScaffold(
      title: Text(packageName),
      slivers: [
        SliverPadding(
          padding: const EdgeInsets.all(16),
          sliver: SliverList(
            delegate: SliverChildListDelegate([
              // Package info card
              if (mergedLicense.allPackageNames.length > 1)
                Card(
                  child: Padding(
                    padding: const EdgeInsets.all(16),
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          t.licenses.relatedPackages,
                          style: Theme.of(context).textTheme.titleMedium
                              ?.copyWith(fontWeight: FontWeight.bold),
                        ),
                        const SizedBox(height: 8),
                        Text(
                          mergedLicense.allPackageNames.join(', '),
                          style: Theme.of(context).textTheme.bodyMedium,
                        ),
                      ],
                    ),
                  ),
                ),
              if (mergedLicense.allPackageNames.length > 1)
                const SizedBox(height: 16),

              // License cards
              ...licenseEntries.asMap().entries.map((entry) {
                final index = entry.key;
                final license = entry.value;
                final isMultipleLicenses = licenseEntries.length > 1;

                return Column(
                  children: [
                    Card(
                      child: Padding(
                        padding: const EdgeInsets.all(16),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(
                              isMultipleLicenses
                                  ? t.licenses.licenseNumber(number: index + 1)
                                  : t.licenses.license,
                              style: Theme.of(context).textTheme.titleMedium
                                  ?.copyWith(fontWeight: FontWeight.bold),
                            ),
                            const SizedBox(height: 16),
                            ...license.paragraphs.map((paragraph) {
                              return Padding(
                                padding: const EdgeInsets.only(bottom: 16),
                                child: SelectableText(
                                  paragraph.text,
                                  style: TextStyle(
                                    fontFamily: paragraph.indent > 0
                                        ? 'monospace'
                                        : null,
                                    fontSize: 14,
                                  ),
                                ),
                              );
                            }),
                          ],
                        ),
                      ),
                    ),
                    if (index < licenseEntries.length - 1)
                      const SizedBox(height: 16),
                  ],
                );
              }),
            ]),
          ),
        ),
      ],
    );
  }
}