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

import '../connections/connection_providers.dart';
import '../routing/route_paths.dart';
import '../theme/theme_mode_provider.dart';
import '../theme/theme_x.dart';

class _NavItem {
  const _NavItem(this.path, this.label, this.icon, this.selectedIcon);
  final String path;
  final String label;
  final IconData icon;
  final IconData selectedIcon;
}

const _navItems = [
  _NavItem(RoutePaths.dashboard, 'Dashboard', Icons.grid_view_outlined, Icons.grid_view_rounded),
  _NavItem(RoutePaths.services, 'Services', Icons.layers_outlined, Icons.layers_rounded),
  _NavItem(RoutePaths.backups, 'Backups', Icons.cloud_outlined, Icons.cloud_rounded),
  _NavItem(RoutePaths.fleet, 'Fleet', Icons.hub_outlined, Icons.hub_rounded),
  _NavItem(RoutePaths.updates, 'Updates', Icons.history_outlined, Icons.history_rounded),
  _NavItem(RoutePaths.settings, 'Settings', Icons.tune_outlined, Icons.tune_rounded),
];

/// The persistent left nav rail + top bar frame wrapping every screen, per
/// the approved mockup. Wraps go_router's `ShellRoute` child.
class NavRailShell extends ConsumerWidget {
  const NavRailShell({super.key, required this.currentPath, required this.child});

  final String currentPath;
  final Widget child;

  int get _selectedIndex {
    final index = _navItems.indexWhere((i) => currentPath.startsWith(i.path));
    return index == -1 ? 0 : index;
  }

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final narrow = MediaQuery.sizeOf(context).width < 860;

    return Scaffold(
      body: Row(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          _Rail(selectedIndex: _selectedIndex, narrow: narrow),
          const VerticalDivider(width: 1, thickness: 1),
          Expanded(
            child: Column(
              children: [
                _TopBar(currentPath: currentPath),
                const Divider(height: 1, thickness: 1),
                Expanded(child: child),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _Rail extends ConsumerWidget {
  const _Rail({required this.selectedIndex, required this.narrow});

  final int selectedIndex;
  final bool narrow;

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

    return SizedBox(
      width: narrow ? 72 : 226,
      child: Container(
        color: context.theme.navigationRailTheme.backgroundColor,
        child: SafeArea(
          child: Column(
            children: [
              Padding(
                padding: const EdgeInsets.fromLTRB(14, 18, 14, 20),
                child: Row(
                  mainAxisAlignment: narrow ? MainAxisAlignment.center : MainAxisAlignment.start,
                  children: [
                    Container(
                      width: 28,
                      height: 28,
                      decoration: BoxDecoration(
                        color: context.colors.primary,
                        borderRadius: BorderRadius.circular(8),
                      ),
                      child: Icon(Icons.hub_rounded, size: 16, color: context.colors.onPrimary),
                    ),
                    if (!narrow) ...[
                      const SizedBox(width: 10),
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          mainAxisSize: MainAxisSize.min,
                          children: [
                            Text('NodeMaster', style: context.text.titleMedium?.copyWith(fontSize: 14.5)),
                            Text('Manager', style: context.text.bodySmall),
                          ],
                        ),
                      ),
                    ],
                  ],
                ),
              ),
              Expanded(
                child: ListView(
                  padding: const EdgeInsets.symmetric(horizontal: 8),
                  children: [
                    for (var i = 0; i < _navItems.length; i++)
                      _RailButton(item: _navItems[i], selected: i == selectedIndex, narrow: narrow),
                  ],
                ),
              ),
              Padding(
                padding: const EdgeInsets.all(12),
                child: _ConnectionChip(name: activeConnection?.name, url: activeConnection?.baseUrl, narrow: narrow),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

class _RailButton extends StatelessWidget {
  const _RailButton({required this.item, required this.selected, required this.narrow});

  final _NavItem item;
  final bool selected;
  final bool narrow;

  @override
  Widget build(BuildContext context) {
    final fg = selected ? context.colors.secondary : context.text.bodyMedium?.color;
    final bg = selected ? context.colors.primary.withValues(alpha: 0.14) : Colors.transparent;

    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 1.5),
      child: Material(
        color: bg,
        borderRadius: BorderRadius.circular(7),
        child: InkWell(
          borderRadius: BorderRadius.circular(7),
          onTap: () => context.go(item.path),
          child: Padding(
            padding: EdgeInsets.symmetric(horizontal: narrow ? 0 : 10, vertical: 9),
            child: Row(
              mainAxisAlignment: narrow ? MainAxisAlignment.center : MainAxisAlignment.start,
              children: [
                Icon(selected ? item.selectedIcon : item.icon, size: 18, color: fg),
                if (!narrow) ...[
                  const SizedBox(width: 10),
                  Text(
                    item.label,
                    style: context.text.bodyMedium?.copyWith(
                      color: fg,
                      fontWeight: selected ? FontWeight.w700 : FontWeight.w500,
                    ),
                  ),
                ],
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _ConnectionChip extends StatelessWidget {
  const _ConnectionChip({required this.name, required this.url, required this.narrow});

  final String? name;
  final String? url;
  final bool narrow;

  @override
  Widget build(BuildContext context) {
    final dot = Container(
      width: 7,
      height: 7,
      decoration: BoxDecoration(
        color: name == null ? context.colors.outline : context.status.good,
        shape: BoxShape.circle,
      ),
    );
    if (narrow) return Center(child: dot);

    return Container(
      padding: const EdgeInsets.all(9),
      decoration: BoxDecoration(
        color: context.colors.surface,
        borderRadius: BorderRadius.circular(8),
        border: Border.all(color: context.colors.outlineVariant),
      ),
      child: Row(
        children: [
          dot,
          const SizedBox(width: 8),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  name ?? 'No connection',
                  maxLines: 1,
                  overflow: TextOverflow.ellipsis,
                  style: context.text.labelLarge?.copyWith(fontSize: 12),
                ),
                if (url != null)
                  Text(
                    url!.replaceFirst(RegExp(r'^https?://'), ''),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                    style: context.dataStyles.dataMonoSmall,
                  ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

const _titles = <String, (String, String Function(WidgetRef))>{
  RoutePaths.dashboard: ('Dashboard', _connSubtitle),
  RoutePaths.services: ('Services', _connSubtitle),
  RoutePaths.backups: ('Backups', _connSubtitle),
  RoutePaths.fleet: ('Fleet', _connSubtitle),
  RoutePaths.updates: ('Updates', _connSubtitle),
  RoutePaths.settings: ('Settings', _connSubtitle),
};

String _connSubtitle(WidgetRef ref) {
  final connection = ref.watch(activeConnectionProvider);
  return connection == null ? 'No connection configured' : 'Connected to ${connection.name}';
}

class _TopBar extends ConsumerWidget {
  const _TopBar({required this.currentPath});

  final String currentPath;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final entry = _titles.entries.firstWhere(
      (e) => currentPath.startsWith(e.key),
      orElse: () => _titles.entries.first,
    );
    final title = entry.value.$1;
    final subtitle = entry.value.$2(ref);

    final mode = ref.watch(themeModeControllerProvider);
    final effectiveDark = switch (mode) {
      ThemeMode.dark => true,
      ThemeMode.light => false,
      ThemeMode.system => MediaQuery.platformBrightnessOf(context) == Brightness.dark,
    };

    return Padding(
      padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 14),
      child: Row(
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(title, style: context.text.titleLarge),
                Text(subtitle, style: context.text.bodySmall),
              ],
            ),
          ),
          IconButton(
            tooltip: effectiveDark ? 'Switch to light theme' : 'Switch to dark theme',
            icon: Icon(effectiveDark ? Icons.dark_mode_outlined : Icons.light_mode_outlined),
            onPressed: () => ref
                .read(themeModeControllerProvider.notifier)
                .setThemeMode(effectiveDark ? ThemeMode.light : ThemeMode.dark),
          ),
        ],
      ),
    );
  }
}