import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:provider/provider.dart';

import '../services/app_state.dart';
import '../services/onboarding_keys.dart';
import '../widgets/cloud_backup_action_button.dart';
import 'data_settings_screen.dart';
import 'faq_screen.dart';
import 'ui_settings_screen.dart';
import 'user_agreement_screen.dart';

/// The "Settings" tab: a landing menu into submenus — [UiSettingsScreen]
/// (appearance) and [DataSettingsScreen] (cloud storage, photo handling,
/// advanced/purge) — plus a read-only summary of what's stored locally.
class SettingsScreen extends StatelessWidget {
  const SettingsScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final appState = context.watch<AppState>();

    return Scaffold(
      appBar: AppBar(
        title: const Text('Settings'),
        actions: const [CloudBackupActionButton(), FaqActionButton()],
      ),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Card(
            child: ListTile(
              leading: const Icon(Icons.palette_outlined),
              title: const Text('UI'),
              subtitle: const Text('Appearance'),
              trailing: const Icon(Icons.chevron_right),
              onTap: () => Navigator.of(context).push(
                MaterialPageRoute(builder: (_) => const UiSettingsScreen()),
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            key: OnboardingKeys.settingsDataMenuEntry,
            child: ListTile(
              leading: const Icon(Icons.storage_outlined),
              title: const Text('Data'),
              subtitle: const Text('Cloud storage, photo syncing, advanced'),
              trailing: const Icon(Icons.chevron_right),
              onTap: () => Navigator.of(context).push(
                MaterialPageRoute(builder: (_) => const DataSettingsScreen()),
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            child: ListTile(
              leading: const Icon(Icons.help_outline),
              title: const Text('FAQ'),
              subtitle: const Text('Common questions about the app and the refund program'),
              trailing: const Icon(Icons.chevron_right),
              onTap: () => Navigator.of(context).push(
                MaterialPageRoute(builder: (_) => const FaqScreen()),
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            child: ListTile(
              leading: const Icon(Icons.description_outlined),
              title: const Text('User Agreement'),
              subtitle: const Text('Data liability, privacy, and the tax-advice disclaimer'),
              trailing: const Icon(Icons.chevron_right),
              onTap: () => Navigator.of(context).push(
                MaterialPageRoute(builder: (_) => const UserAgreementScreen(isReview: true)),
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Ads', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  if (appState.adsCurrentlyDisabled) ...[
                    Text(
                      'Ads are disabled until '
                      '${DateFormat.yMMMd().format(appState.adFreeUntil!.toLocal())}.',
                      style: Theme.of(context).textTheme.bodyMedium,
                    ),
                  ] else ...[
                    Text(
                      'Syncing your data to the cloud requires watching a short ad — '
                      'at most once every 5 minutes.',
                      style: Theme.of(context).textTheme.bodyMedium,
                    ),
                    const SizedBox(height: 12),
                    if (appState.purchaseError != null) ...[
                      Text(
                        appState.purchaseError!,
                        style: TextStyle(color: Theme.of(context).colorScheme.error),
                      ),
                      const SizedBox(height: 8),
                    ],
                    FilledButton.icon(
                      onPressed: () => context.read<AppState>().buyAdFreeYear(),
                      icon: const Icon(Icons.block),
                      label: Text(
                        appState.adFreeYearPriceLabel == null
                            ? 'Remove Ads for a Year'
                            : 'Remove Ads for a Year — ${appState.adFreeYearPriceLabel}',
                      ),
                    ),
                    TextButton(
                      onPressed: () {
                        context.read<AppState>().restoreAdFreeYear();
                        ScaffoldMessenger.of(context).showSnackBar(
                          const SnackBar(
                            content: Text(
                              "Checking for a previous purchase on this Google account…",
                            ),
                          ),
                        );
                      },
                      child: const Text('Restore Purchase'),
                    ),
                  ],
                ],
              ),
            ),
          ),
          const SizedBox(height: 16),
          Card(
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text('Summary', style: Theme.of(context).textTheme.titleMedium),
                  const SizedBox(height: 8),
                  Text('${appState.vehicles.length} vehicle(s)'),
                  Text('${appState.fuelEntries.length} fuel entries'),
                  Text('${appState.totalGallonsAllVehicles.toStringAsFixed(3)} total gallons logged'),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}