import 'dart:async';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../models/nymea_models.dart';
import '../models/thing_category.dart';
import '../services/nymea_service.dart';
import '../theme/app_theme.dart';
import '../main.dart' show DrawerMenuButton;
import 'category_overview_screen.dart';

// ─────────────────────────────────────────────────────────────────────────────
//  ThingsScreen — NIVEAU 1
//  Grille 2 colonnes : une tuile par catégorie présente.
//  Chaque tuile affiche l'icône/nom de catégorie et un carousel des things.
// ─────────────────────────────────────────────────────────────────────────────

class ThingsScreen extends StatelessWidget {
  const ThingsScreen({super.key});

  static const _orderedCats = [
    ThingCategory.energy, ThingCategory.solar, ThingCategory.battery,
    ThingCategory.evCharger, ThingCategory.cars, ThingCategory.hvac,
    ThingCategory.lighting, ThingCategory.sensors, ThingCategory.network,
    ThingCategory.notifications, ThingCategory.weather, ThingCategory.media,
    ThingCategory.other,
  ];

  @override
  Widget build(BuildContext context) {
    final service = context.watch<NymeaService>();
    final things = service.things.where((t) => t.id.isNotEmpty).toList();
    final classes = service.thingClasses;

    // Groupement par catégorie
    final Map<ThingCategory, List<NymeaThing>> grouped = {};
    for (final t in things) {
      final cls = _classFor(t, classes);
      final cat = cls?.category ?? ThingCategory.other;
      grouped.putIfAbsent(cat, () => []).add(t);
    }
    final cats = _orderedCats.where((c) => grouped.containsKey(c)).toList();

    return Scaffold(
      backgroundColor: AppTheme.backgroundGray,
      appBar: _buildAppBar(service, things.length),
      body: !service.isConnected
          ? _buildPlaceholder(
              icon: Icons.cloud_off_rounded,
              label: 'Non connecté à nymea',
            )
          : things.isEmpty && !service.thingsLoaded
              ? const Center(
                  child: CircularProgressIndicator(color: AppTheme.accentTeal))
              : things.isEmpty
                  ? _buildPlaceholder(
                      icon: Icons.devices_other_rounded,
                      label: 'Aucun appareil',
                    )
                  : GridView.builder(
                      padding: const EdgeInsets.fromLTRB(16, 12, 16, 100),
                      gridDelegate:
                          const SliverGridDelegateWithFixedCrossAxisCount(
                        crossAxisCount: 2,
                        crossAxisSpacing: 10,
                        mainAxisSpacing: 10,
                        childAspectRatio: 0.98,
                      ),
                      // Si les classes ne sont pas encore chargées → 1 tuile "Autres"
                      itemCount: cats.isEmpty ? 1 : cats.length,
                      itemBuilder: (context, i) {
                        final cat = cats.isEmpty ? ThingCategory.other : cats[i];
                        final catThings = grouped[cat] ?? things;
                        final info = categoryInfoMap[cat]!;
                        return _CategoryTile(
                          info: info,
                          things: catThings,
                          thingClasses: classes,
                          onTap: () => Navigator.push(
                            context,
                            MaterialPageRoute(
                              builder: (_) => CategoryOverviewScreen(
                                info: info,
                                things: catThings,
                                thingClasses: classes,
                              ),
                            ),
                          ),
                        );
                      },
                    ),
    );
  }

  AppBar _buildAppBar(NymeaService service, int count) {
    return AppBar(
      backgroundColor: AppTheme.backgroundGray,
      elevation: 0,
      leading: const DrawerMenuButton(),
      leadingWidth: 56,
      title: Row(children: [
        const Text('Things',
            style: TextStyle(
                fontWeight: FontWeight.bold,
                color: AppTheme.textDark,
                fontSize: 20)),
        const SizedBox(width: 8),
        Container(
          padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 2),
          decoration: BoxDecoration(
            color: AppTheme.accentTeal.withValues(alpha: 0.15),
            borderRadius: BorderRadius.circular(10),
          ),
          child: Text('$count',
              style: const TextStyle(
                  fontSize: 12,
                  fontWeight: FontWeight.bold,
                  color: AppTheme.accentTeal)),
        ),
      ]),
      actions: [
        IconButton(
          icon: const Icon(Icons.refresh_rounded, color: AppTheme.textDark),
          onPressed: () => service.refresh(),
        ),
      ],
    );
  }

  static Widget _buildPlaceholder(
          {required IconData icon, required String label}) =>
      Center(
        child: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
          Icon(icon, size: 64, color: Colors.grey[400]),
          const SizedBox(height: 12),
          Text(label,
              style:
                  const TextStyle(color: AppTheme.textLight, fontSize: 16)),
        ]),
      );

  static NymeaThingClass? _classFor(
      NymeaThing t, List<NymeaThingClass> classes) {
    try {
      return classes.firstWhere((c) => c.id == t.thingClassId);
    } catch (_) {
      return null;
    }
  }
}

// ─────────────────────────────────────────────────────────────────────────────
//  _CategoryTile — tuile d'une catégorie
//
//  ┌────────────────────────────┐
//  │      [icône catégorie]     │  ← centrée, colorée
//  │    NOM CATÉGORIE (CAPS)    │
//  │────────────────────────────│  ← séparateur couleur catégorie
//  │ ● Thing name      valeur   │  ← carousel auto (3 s) si >1 thing
//  └────────────────────────────┘
// ─────────────────────────────────────────────────────────────────────────────

class _CategoryTile extends StatefulWidget {
  final ThingCategoryInfo info;
  final List<NymeaThing> things;
  final List<NymeaThingClass> thingClasses;
  final VoidCallback onTap;

  const _CategoryTile({
    required this.info,
    required this.things,
    required this.thingClasses,
    required this.onTap,
  });

  @override
  State<_CategoryTile> createState() => _CategoryTileState();
}

class _CategoryTileState extends State<_CategoryTile> {
  int _idx = 0;
  Timer? _timer;

  @override
  void initState() {
    super.initState();
    if (widget.things.length > 1) {
      _timer = Timer.periodic(const Duration(seconds: 3), (_) {
        if (mounted) {
          setState(
              () => _idx = (_idx + 1) % widget.things.length);
        }
      });
    }
  }

  @override
  void dispose() {
    _timer?.cancel();
    super.dispose();
  }

  NymeaThingClass? _cls(NymeaThing t) {
    try {
      return widget.thingClasses.firstWhere((c) => c.id == t.thingClassId);
    } catch (_) {
      return null;
    }
  }

  bool _isOnline(NymeaThing t, NymeaThingClass? cls) {
    final ct =
        cls?.stateTypes.where((s) => s.name.toLowerCase() == 'connected');
    if (ct != null && ct.isNotEmpty) {
      final v = t.stateValue(ct.first.id);
      return v == true || v == 'true';
    }
    return t.isSetupComplete;
  }

  String? _primaryValue(NymeaThing t, NymeaThingClass? cls) {
    final p = cls?.primaryStateType;
    if (p == null) return null;
    return p.formatValue(t.stateValue(p.id));
  }

  @override
  Widget build(BuildContext context) {
    // Clamp _idx au cas où la liste shrink entre deux ticks du timer
    final safeIdx = _idx.clamp(0, widget.things.length - 1);
    final current = widget.things[safeIdx];
    final cls = _cls(current);
    final online = _isOnline(current, cls);
    final value = _primaryValue(current, cls);
    final info = widget.info;

    return Material(
      color: AppTheme.cardWhite,
      borderRadius: BorderRadius.circular(AppTheme.cornerRadius),
      child: InkWell(
        onTap: widget.onTap,
        borderRadius: BorderRadius.circular(AppTheme.cornerRadius),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // ── Haut : icône + nom catégorie ───────────────────────────────
            Expanded(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Container(
                    width: 52,
                    height: 52,
                    decoration: BoxDecoration(
                      color: info.color.withValues(alpha: 0.13),
                      borderRadius: BorderRadius.circular(14),
                    ),
                    child: Icon(info.icon, color: info.color, size: 28),
                  ),
                  const SizedBox(height: 10),
                  Padding(
                    padding: const EdgeInsets.symmetric(horizontal: 10),
                    child: Text(
                      info.label.toUpperCase(),
                      style: TextStyle(
                        fontSize: 10,
                        fontWeight: FontWeight.w800,
                        color: AppTheme.textDark.withValues(alpha: 0.75),
                        letterSpacing: 0.7,
                      ),
                      textAlign: TextAlign.center,
                      maxLines: 2,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                ],
              ),
            ),

            // ── Séparateur coloré ───────────────────────────────────────────
            Container(
              height: 1,
              color: info.color.withValues(alpha: 0.25),
            ),

            // ── Bas : carousel des things ───────────────────────────────────
            SizedBox(
              height: 52,
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 12),
                child: AnimatedSwitcher(
                  duration: const Duration(milliseconds: 350),
                  transitionBuilder: (child, anim) =>
                      FadeTransition(opacity: anim, child: child),
                  child: _CarouselRow(
                    key: ValueKey(_idx),
                    name: current.name,
                    value: value,
                    count: widget.things.length,
                    index: _idx,
                    isOnline: online,
                    color: info.color,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

// ── Ligne carousel ────────────────────────────────────────────────────────────

class _CarouselRow extends StatelessWidget {
  final String name;
  final String? value;
  final int count;
  final int index;
  final bool isOnline;
  final Color color;

  const _CarouselRow({
    super.key,
    required this.name,
    required this.value,
    required this.count,
    required this.index,
    required this.isOnline,
    required this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        // Pastille statut
        Container(
          width: 7,
          height: 7,
          decoration: BoxDecoration(
            color: isOnline ? color : Colors.grey[400],
            shape: BoxShape.circle,
          ),
        ),
        const SizedBox(width: 8),
        // Nom du thing
        Expanded(
          child: Text(
            name,
            style: const TextStyle(
                fontSize: 12,
                fontWeight: FontWeight.w500,
                color: AppTheme.textDark),
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        ),
        const SizedBox(width: 4),
        // Valeur primaire — Flexible pour éviter l'overflow
        Flexible(
          fit: FlexFit.loose,
          child: Text(
            value ?? '—',
            style: TextStyle(
              fontSize: 13,
              fontWeight: FontWeight.bold,
              color: isOnline ? color : AppTheme.textLight,
            ),
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        ),
      ],
    );
  }
}

// ─────────────────────────────────────────────────────────────────────────────
//  ThingCard — conservé pour compatibilité externe
// ─────────────────────────────────────────────────────────────────────────────

class ThingCard extends StatelessWidget {
  final NymeaThing thing;
  final NymeaThingClass? thingClass;
  final ThingCategoryInfo categoryInfo;
  final VoidCallback onTap;

  const ThingCard({
    super.key,
    required this.thing,
    required this.thingClass,
    required this.categoryInfo,
    required this.onTap,
  });

  @override
  Widget build(BuildContext context) {
    final primary = thingClass?.primaryStateType;
    final value = primary?.formatValue(thing.stateValue(primary.id));
    return ListTile(
      leading: Icon(categoryInfo.icon, color: categoryInfo.color),
      title: Text(thing.name),
      trailing:
          value != null ? Text(value, style: TextStyle(color: categoryInfo.color)) : null,
      onTap: onTap,
    );
  }
}