import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:lucide_icons_flutter/lucide_icons.dart';

import '../core/permissions.dart';
import '../core/theme.dart';
import '../state/profile_controller.dart';
import '../state/seed.dart';
import '../state/session_controller.dart';
import '../state/shifts_controller.dart';
import '../state/timecards_controller.dart';
import '../widgets/common.dart';

class SettingsScreen extends ConsumerStatefulWidget {
  const SettingsScreen({super.key});

  @override
  ConsumerState<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends ConsumerState<SettingsScreen> {
  @override
  void initState() {
    super.initState();
    // A permission can be revoked in system settings while the app is closed,
    // so the switches are re-read from the OS rather than trusted from cache.
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ref.read(sessionProvider.notifier).refresh();
    });
  }

  /// The OS has no API to revoke a permission, and re-requesting a granted one
  /// does nothing — so the switch hands off to the system settings page for
  /// anything it cannot do itself.
  Future<void> _toggle(AppPermission permission, bool value) async {
    final notifier = ref.read(sessionProvider.notifier);
    if (!value) {
      await ref.read(permissionServiceProvider).openSettings();
      return;
    }
    final granted = await notifier.request(permission);
    if (granted || !mounted) return;
    await ref.read(permissionServiceProvider).openSettings();
  }

  @override
  Widget build(BuildContext context) {
    final session = ref.watch(sessionProvider);
    final profile = ref.watch(profileProvider);
    final reviewCount = ref.watch(timecardsNeedingReviewProvider).length;

    return Scaffold(
      appBar: AppBar(
        title: const Text('Settings'),
        actions: const [
          Padding(
            padding: EdgeInsets.only(right: 16),
            child: Center(child: StatusChip('v1.1.1', tone: ChipTone.yellow)),
          ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
        children: [
          const SectionLabel('Permissions'),
          KrowCard(
            padding: const EdgeInsets.symmetric(horizontal: 16),
            child: Column(
              children: [
                _SwitchRow(
                  icon: LucideIcons.mapPin,
                  title: 'Location',
                  subtitle: 'Needed to clock in at the venue',
                  value: session.locationGranted,
                  onChanged: (v) => _toggle(AppPermission.location, v),
                ),
                const Divider(height: 1),
                _SwitchRow(
                  icon: LucideIcons.bell,
                  title: 'Notifications',
                  subtitle: 'Shift offers, reminders and pay alerts',
                  value: session.notificationsGranted,
                  onChanged: (v) => _toggle(AppPermission.notifications, v),
                ),
                const Divider(height: 1),
                _SwitchRow(
                  icon: LucideIcons.camera,
                  title: 'Camera',
                  subtitle: 'Photograph documents and attire',
                  value: session.cameraGranted,
                  onChanged: (v) => _toggle(AppPermission.camera, v),
                ),
              ],
            ),
          ),
          const SectionLabel('Money'),
          TileGroup(
            children: [
              NavTile(
                icon: LucideIcons.landmark,
                title: 'Direct deposit',
                subtitle: profile.bank == null
                    ? 'Where your pay lands'
                    : profile.bank!.bankName,
                badge: profile.bank == null
                    ? const StatusChip('Add', tone: ChipTone.yellow)
                    : null,
                onTap: () => context.push('/direct-deposit'),
              ),
              NavTile(
                icon: LucideIcons.clock,
                title: 'Timecards',
                subtitle: 'Hours worked and disputes',
                badge: reviewCount > 0
                    ? StatusChip('$reviewCount', tone: ChipTone.yellow)
                    : null,
                onTap: () => context.push('/timecards'),
              ),
              NavTile(
                icon: LucideIcons.calendarDays,
                title: 'Payroll schedule',
                subtitle: 'When each period closes and pays',
                onTap: () => context.push('/payroll'),
              ),
            ],
          ),
          const SectionLabel('Support'),
          TileGroup(
            children: [
              NavTile(
                icon: LucideIcons.lifeBuoy,
                title: 'Contact support',
                subtitle: 'Usually answered within 4 hours',
                onTap: () => context.push('/support'),
              ),
              NavTile(
                icon: LucideIcons.circleHelp,
                title: 'FAQs',
                subtitle: 'Common questions answered',
                onTap: () => context.push('/faqs'),
              ),
              NavTile(
                icon: LucideIcons.shield,
                title: 'Privacy & security',
                subtitle: 'Account and data settings',
                onTap: () => context.push('/privacy'),
              ),
            ],
          ),
          const SizedBox(height: 22),
          OutlinedButton.icon(
            onPressed: () => _signOut(context, ref),
            icon: const Icon(LucideIcons.logOut, size: 18),
            label: const Text('Sign out'),
          ),
          const SizedBox(height: 22),
          const Center(
            child: Text(
              'VERSION 1.1.1 · BUILD 26',
              style: TextStyle(
                fontSize: 11,
                letterSpacing: 1.2,
                color: Color(0xFF949FA5),
              ),
            ),
          ),
        ],
      ),
    );
  }

  Future<void> _signOut(BuildContext context, WidgetRef ref) async {
    final ok = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Sign out?'),
        content: const Text('You will need to verify your number again.'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Stay'),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(context, true),
            style: FilledButton.styleFrom(minimumSize: const Size(0, 44)),
            child: const Text('Sign out'),
          ),
        ],
      ),
    );
    if (ok != true || !context.mounted) return;
    await ref.read(sessionProvider.notifier).signOut();
    if (!context.mounted) return;
    context.go('/welcome');
  }
}

class _SwitchRow extends StatelessWidget {
  const _SwitchRow({
    required this.icon,
    required this.title,
    required this.subtitle,
    required this.value,
    required this.onChanged,
  });

  final IconData icon;
  final String title;
  final String subtitle;
  final bool value;
  final ValueChanged<bool> onChanged;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8),
      child: Row(
        children: [
          Container(
            width: 40,
            height: 40,
            decoration: BoxDecoration(
              color: KrowPalette.blueTint,
              borderRadius: BorderRadius.circular(11),
            ),
            child: Icon(icon, size: 18, color: KrowPalette.blue),
          ),
          const SizedBox(width: 13),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  title,
                  style: const TextStyle(
                    fontSize: 14.5,
                    fontWeight: FontWeight.w600,
                  ),
                ),
                Text(
                  subtitle,
                  style: const TextStyle(fontSize: 12, color: KrowPalette.mute),
                ),
              ],
            ),
          ),
          Switch(value: value, onChanged: onChanged),
        ],
      ),
    );
  }
}

/// Pick what it is about so it reaches the right person first time.
class SupportScreen extends ConsumerStatefulWidget {
  const SupportScreen({super.key});

  @override
  ConsumerState<SupportScreen> createState() => _SupportScreenState();
}

class _SupportScreenState extends ConsumerState<SupportScreen> {
  String _topic = Seed.supportTopics.first;
  String? _shiftId;
  final _message = TextEditingController();

  @override
  void dispose() {
    _message.dispose();
    super.dispose();
  }

  void _send() {
    if (_message.text.trim().length < 10) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Tell us a little more than that')),
      );
      return;
    }
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text('Sent to support · $_topic')));
    Navigator.of(context).pop();
  }

  @override
  Widget build(BuildContext context) {
    final shifts = ref.watch(shiftsProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Get help'),
        actions: const [
          Padding(
            padding: EdgeInsets.only(right: 16),
            child: Center(child: StatusChip('~4 hr reply')),
          ),
        ],
      ),
      body: ListView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
        children: [
          const Text(
            'Pick what it is about so it reaches the right person first time.',
            style: TextStyle(
              fontSize: 13.5,
              height: 1.55,
              color: KrowPalette.mute,
            ),
          ),
          const SectionLabel("What's it about?"),
          Wrap(
            spacing: 7,
            runSpacing: 7,
            children: [
              for (final t in Seed.supportTopics)
                ChoiceChip(
                  label: Text(t),
                  selected: t == _topic,
                  showCheckmark: false,
                  selectedColor: KrowPalette.blue,
                  labelStyle: TextStyle(
                    fontSize: 12.5,
                    fontWeight: FontWeight.w500,
                    color: t == _topic ? Colors.white : KrowPalette.mute,
                  ),
                  onSelected: (_) => setState(() => _topic = t),
                ),
            ],
          ),
          const SectionLabel('Which shift?'),
          DropdownButtonFormField<String>(
            initialValue: _shiftId,
            isExpanded: true,
            decoration: const InputDecoration(
              hintText: 'Not about a specific shift',
            ),
            items: [
              for (final s in shifts)
                DropdownMenuItem(
                  value: s.id,
                  child: Text(
                    '${s.role} · ${s.business}',
                    overflow: TextOverflow.ellipsis,
                  ),
                ),
            ],
            onChanged: (v) => setState(() => _shiftId = v),
          ),
          const SectionLabel('Tell us what happened'),
          TextField(
            controller: _message,
            maxLines: 5,
            maxLength: 500,
            decoration: const InputDecoration(
              hintText: 'The venue door was locked when I arrived...',
            ),
          ),
          TextButton.icon(
            onPressed: () => ScaffoldMessenger.of(context).showSnackBar(
              const SnackBar(content: Text('Attachments open the camera roll')),
            ),
            icon: const Icon(LucideIcons.paperclip, size: 16),
            label: const Text('Attach a photo'),
          ),
          const SizedBox(height: 16),
          FilledButton(onPressed: _send, child: const Text('Send to support')),
        ],
      ),
    );
  }
}

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

  @override
  State<FaqScreen> createState() => _FaqScreenState();
}

class _FaqScreenState extends State<FaqScreen> {
  String _query = '';

  @override
  Widget build(BuildContext context) {
    final q = _query.toLowerCase();

    return Scaffold(
      appBar: AppBar(title: const Text('Questions')),
      body: ListView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
        children: [
          TextField(
            onChanged: (v) => setState(() => _query = v),
            decoration: const InputDecoration(
              hintText: 'Search help',
              prefixIcon: Icon(LucideIcons.search, size: 18),
            ),
          ),
          for (final entry in Seed.faqs.entries)
            () {
              final matches = entry.value
                  .where(
                    (f) =>
                        q.isEmpty ||
                        f.$1.toLowerCase().contains(q) ||
                        f.$2.toLowerCase().contains(q),
                  )
                  .toList();
              if (matches.isEmpty) return const SizedBox.shrink();
              return Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  SectionLabel(entry.key),
                  KrowCard(
                    padding: const EdgeInsets.symmetric(horizontal: 4),
                    child: Column(
                      children: [
                        for (var i = 0; i < matches.length; i++) ...[
                          if (i > 0) const Divider(height: 1),
                          ExpansionTile(
                            shape: const Border(),
                            collapsedShape: const Border(),
                            tilePadding: const EdgeInsets.symmetric(
                              horizontal: 12,
                            ),
                            childrenPadding: const EdgeInsets.fromLTRB(
                              12,
                              0,
                              12,
                              14,
                            ),
                            title: Text(
                              matches[i].$1,
                              style: const TextStyle(
                                fontSize: 14,
                                fontWeight: FontWeight.w500,
                              ),
                            ),
                            children: [
                              Align(
                                alignment: Alignment.centerLeft,
                                child: Text(
                                  matches[i].$2,
                                  style: const TextStyle(
                                    fontSize: 13,
                                    height: 1.55,
                                    color: KrowPalette.mute,
                                  ),
                                ),
                              ),
                            ],
                          ),
                        ],
                      ],
                    ),
                  ),
                ],
              );
            }(),
        ],
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final profile = ref.watch(profileProvider);

    return Scaffold(
      appBar: AppBar(title: const Text('Privacy & security')),
      body: ListView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 28),
        children: [
          const SectionLabel('Legal'),
          TileGroup(
            children: [
              NavTile(
                icon: LucideIcons.fileText,
                title: 'Terms of service',
                subtitle: 'Updated 14 Jun 2026',
                onTap: () => _open(context, 'Terms of service'),
              ),
              NavTile(
                icon: LucideIcons.shield,
                title: 'Privacy policy',
                subtitle: 'What we collect and why',
                onTap: () => _open(context, 'Privacy policy'),
              ),
            ],
          ),
          const SectionLabel('Who sees your data'),
          TileGroup(
            children: [
              NavTile(
                icon: LucideIcons.briefcase,
                title: "Businesses you've worked for",
                subtitle: '2 have access to your documents',
                onTap: () => _open(context, 'Data sharing'),
              ),
            ],
          ),
          const SectionLabel('Email'),
          KrowCard(
            padding: const EdgeInsets.fromLTRB(16, 8, 8, 8),
            child: Row(
              children: [
                Container(
                  width: 40,
                  height: 40,
                  decoration: BoxDecoration(
                    color: KrowPalette.blueTint,
                    borderRadius: BorderRadius.circular(11),
                  ),
                  child: const Icon(
                    LucideIcons.mail,
                    size: 18,
                    color: KrowPalette.blue,
                  ),
                ),
                const SizedBox(width: 13),
                const Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'KROW newsletter',
                        style: TextStyle(
                          fontSize: 14.5,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                      Text(
                        'Product news and operational tips',
                        style: TextStyle(fontSize: 12, color: KrowPalette.mute),
                      ),
                    ],
                  ),
                ),
                Switch(
                  value: profile.newsletter,
                  onChanged: (v) =>
                      ref.read(profileProvider.notifier).setNewsletter(v),
                ),
              ],
            ),
          ),
          const SectionLabel('Account'),
          KrowCard(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                const Text(
                  'Delete your account',
                  style: TextStyle(fontSize: 14.5, fontWeight: FontWeight.w600),
                ),
                const SizedBox(height: 3),
                const Text(
                  'Permanent. Timecards and tax records are kept for 4 years '
                  'by law, then destroyed.',
                  style: TextStyle(
                    fontSize: 12,
                    height: 1.45,
                    color: KrowPalette.mute,
                  ),
                ),
                const SizedBox(height: 14),
                OutlinedButton.icon(
                  onPressed: () => _confirmDelete(context),
                  icon: const Icon(LucideIcons.trash2, size: 18),
                  label: const Text('Delete account'),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

  void _open(BuildContext context, String title) {
    ScaffoldMessenger.of(
      context,
    ).showSnackBar(SnackBar(content: Text('$title opens in the browser')));
  }

  Future<void> _confirmDelete(BuildContext context) async {
    await showDialog<void>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Delete your account?'),
        content: const Text(
          'This cannot be undone. To go ahead, contact support so we can '
          'confirm it is really you.',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: const Text('Keep my account'),
          ),
          FilledButton(
            onPressed: () {
              Navigator.pop(context);
              context.push('/support');
            },
            style: FilledButton.styleFrom(minimumSize: const Size(0, 44)),
            child: const Text('Contact support'),
          ),
        ],
      ),
    );
  }
}