import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../backend/backend.dart';
import 'router.dart';
import 'theme.dart';

class GelRuleApp extends ConsumerWidget {
  const GelRuleApp({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final database = ref.watch(appDatabaseProvider);
    final settings = ref.watch(appSettingsProvider);
    final router = ref.watch(appRouterProvider);

    return database.when(
      loading: () => const MaterialApp(
        debugShowCheckedModeBanner: false,
        home: _StartupLoadingScreen(),
      ),
      error: (error, _) => MaterialApp(
        debugShowCheckedModeBanner: false,
        theme: buildTheme(Brightness.light),
        darkTheme: buildTheme(Brightness.dark),
        themeMode: ThemeMode.dark,
        home: _StartupErrorScreen(error: error),
      ),
      data: (_) => MaterialApp.router(
        title: 'GelRule',
        debugShowCheckedModeBanner: false,
        theme: buildTheme(Brightness.light),
        darkTheme: buildTheme(Brightness.dark),
        themeMode: settings.maybeWhen(
          data: (value) => parseThemeMode(value.themeMode),
          orElse: () => ThemeMode.dark,
        ),
        routerConfig: router,
      ),
    );
  }
}

final appSettingsProvider = FutureProvider<AppSettings>((ref) {
  return ref.watch(settingsServiceProvider).getSettings().then(
        (result) => result.fold(
          onSuccess: (settings) => settings,
          onError: (_) => AppSettings.defaults,
        ),
      );
});

class _StartupLoadingScreen extends StatelessWidget {
  const _StartupLoadingScreen();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF101114),
      body: Center(
        child: CircularProgressIndicator(
          color: ColorScheme.fromSeed(
            seedColor: const Color(0xFFE84D8A),
            brightness: Brightness.dark,
          ).primary,
        ),
      ),
    );
  }
}

class _StartupErrorScreen extends ConsumerWidget {
  const _StartupErrorScreen({required this.error});

  final Object error;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    return Scaffold(
      body: SafeArea(
        child: Center(
          child: Padding(
            padding: const EdgeInsets.all(24),
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                const Icon(Icons.storage_rounded, size: 48),
                const SizedBox(height: 16),
                Text(
                  'Could not start local database',
                  style: Theme.of(context).textTheme.titleLarge,
                  textAlign: TextAlign.center,
                ),
                const SizedBox(height: 8),
                Text(
                  '$error',
                  textAlign: TextAlign.center,
                  maxLines: 5,
                  overflow: TextOverflow.ellipsis,
                ),
                const SizedBox(height: 18),
                FilledButton.icon(
                  onPressed: () => ref.invalidate(appDatabaseProvider),
                  icon: const Icon(Icons.refresh_rounded),
                  label: const Text('Retry'),
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}