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

import '../../core/api/common_providers.dart';
import '../home/providers.dart' show dataQualityProvider;
import 'nav_destinations.dart';

/// The Grimmory-style sidebar shown at the extended breakpoint (>=1200): destinations
/// grouped under muted caps headers, a left accent bar on the active row, a counter next
/// to a destination where one is meaningful, and the signed-in account pinned at the
/// bottom. Below 1200 the shell falls back to a plain [NavigationRail] — there is no room
/// for group headers or a profile block in an icon-only rail.
class NavSidebar extends ConsumerWidget {
  const NavSidebar({required this.selectedIndex, required this.onSelect, super.key});

  final int selectedIndex;
  final ValueChanged<int> onSelect;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final issueCount = ref.watch(dataQualityProvider).valueOrNull?.data.length;

    final byGroup = <NavGroup, List<int>>{};
    for (var i = 0; i < navDestinations.length; i++) {
      byGroup.putIfAbsent(navDestinations[i].group, () => []).add(i);
    }

    return Container(
      width: 240,
      color: Theme.of(context).colorScheme.surfaceContainerLow,
      child: Column(
        children: [
          Expanded(
            child: ListView(
              padding: const EdgeInsets.symmetric(vertical: 12),
              children: [
                for (final group in NavGroup.values)
                  if (byGroup[group] case final indices?)
                    _NavGroupSection(
                      label: navGroupLabels[group]!,
                      children: [
                        for (final i in indices)
                          _NavRow(
                            destination: navDestinations[i],
                            selected: i == selectedIndex,
                            counter: navDestinations[i].path == '/health' ? issueCount : null,
                            onTap: () => onSelect(i),
                          ),
                      ],
                    ),
              ],
            ),
          ),
          const Divider(height: 1),
          const _ProfileFooter(),
        ],
      ),
    );
  }
}

class _NavGroupSection extends StatelessWidget {
  const _NavGroupSection({required this.label, required this.children});

  final String label;
  final List<Widget> children;

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Padding(
          padding: const EdgeInsets.fromLTRB(20, 12, 12, 6),
          child: Text(
            label,
            style: Theme.of(context).textTheme.labelSmall?.copyWith(
                  color: scheme.onSurfaceVariant,
                  letterSpacing: 1.1,
                  fontWeight: FontWeight.w600,
                ),
          ),
        ),
        ...children,
      ],
    );
  }
}

class _NavRow extends StatelessWidget {
  const _NavRow({required this.destination, required this.selected, required this.onTap, this.counter});

  final NavDestination destination;
  final bool selected;
  final VoidCallback onTap;
  final int? counter;

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;
    return Padding(
      padding: const EdgeInsets.fromLTRB(8, 0, 12, 2),
      child: Material(
        color: selected ? scheme.primaryContainer.withValues(alpha: 0.35) : Colors.transparent,
        borderRadius: BorderRadius.circular(10),
        child: InkWell(
          borderRadius: BorderRadius.circular(10),
          onTap: onTap,
          child: Padding(
            padding: const EdgeInsets.symmetric(vertical: 9),
            child: Row(
              children: [
                Container(
                  width: 3,
                  height: 18,
                  margin: const EdgeInsets.only(right: 9),
                  decoration: BoxDecoration(
                    color: selected ? scheme.primary : Colors.transparent,
                    borderRadius: BorderRadius.circular(2),
                  ),
                ),
                Icon(
                  selected ? destination.selectedIcon : destination.icon,
                  size: 20,
                  color: selected ? scheme.primary : scheme.onSurfaceVariant,
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Text(
                    destination.label,
                    overflow: TextOverflow.ellipsis,
                    style: TextStyle(
                      color: selected ? scheme.primary : scheme.onSurface,
                      fontWeight: selected ? FontWeight.w600 : FontWeight.w400,
                    ),
                  ),
                ),
                if (counter != null && counter! > 0)
                  Text(
                    '$counter',
                    style: Theme.of(context).textTheme.bodySmall?.copyWith(color: scheme.onSurfaceVariant),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

class _ProfileFooter extends ConsumerWidget {
  const _ProfileFooter();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final scheme = Theme.of(context).colorScheme;
    final theme = Theme.of(context);
    final email = ref.watch(meProvider).valueOrNull?.email;
    final name = email?.split('@').first;
    final initial = (name?.isNotEmpty ?? false) ? name![0].toUpperCase() : '?';

    return Padding(
      padding: const EdgeInsets.all(16),
      child: Row(
        children: [
          CircleAvatar(
            radius: 18,
            backgroundColor: scheme.primaryContainer,
            child: Text(
              initial,
              style: TextStyle(color: scheme.onPrimaryContainer, fontWeight: FontWeight.w700),
            ),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(
                  name ?? '…',
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.bodyMedium?.copyWith(fontWeight: FontWeight.w600),
                ),
                Text(
                  email ?? '',
                  overflow: TextOverflow.ellipsis,
                  style: theme.textTheme.bodySmall?.copyWith(color: scheme.onSurfaceVariant),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}