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/etm_tokens.dart';
import '../main.dart' show DrawerMenuButton;
import 'category_overview_screen.dart';

// ─────────────────────────────────────────────────────────────────────────────
//  ThingsScreen — grille de catégories à hauteur intrinsèque
//
//  Règle : pas de GridView avec childAspectRatio figé.
//  Layout : Column de Row(Expanded × 2) → hauteur naturelle par catégorie.
// ─────────────────────────────────────────────────────────────────────────────

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

  @override
  State<ThingsScreen> createState() => _ThingsScreenState();
}

class _ThingsScreenState extends State<ThingsScreen> {
  static const _orderedCats = [
    ThingCategory.solar,    ThingCategory.battery,
    ThingCategory.evCharger, ThingCategory.hvac,
    ThingCategory.energy,   ThingCategory.cars,
    ThingCategory.lighting, ThingCategory.sensors,
    ThingCategory.network,  ThingCategory.weather,
    ThingCategory.media,    ThingCategory.notifications,
    ThingCategory.other,
  ];

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final service = context.read<NymeaService>();
      if (!service.connected) service.startSimulation();
    });
  }

  @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();

    // Statut global
    final allOnline = things.isNotEmpty &&
        things.every((t) => _isOnline(t, _classFor(t, classes)));
    final offlineCount = things.where((t) => !_isOnline(t, _classFor(t, classes))).length;

    return Scaffold(
      backgroundColor: EtmTokens.bg,
      body: CustomScrollView(
        slivers: [
          // AppBar
          SliverAppBar(
            floating: true,
            backgroundColor: EtmTokens.bg,
            elevation: 0,
            leading: const DrawerMenuButton(),
            leadingWidth: 64,
            title: Row(
              children: [
                Text('Things',
                    style: EtmTokens.sans(size: 20, weight: FontWeight.w600)),
                const SizedBox(width: 8),
                if (things.isNotEmpty)
                  Container(
                    padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 3),
                    decoration: BoxDecoration(
                      color: EtmTokens.greenSoft,
                      borderRadius: BorderRadius.circular(8),
                    ),
                    child: Text('${things.length}',
                        style: EtmTokens.mono(size: 12, weight: FontWeight.w700,
                            color: EtmTokens.greenDark)),
                  ),
              ],
            ),
            actions: [
              Padding(
                padding: const EdgeInsets.only(right: 8),
                child: IconButton(
                  icon: const Icon(Icons.refresh_rounded,
                      color: EtmTokens.muted, size: 20),
                  onPressed: service.refresh,
                ),
              ),
            ],
          ),

          // Body
          SliverPadding(
            padding: const EdgeInsets.fromLTRB(18, 4, 18, 32),
            sliver: SliverList(
              delegate: SliverChildListDelegate([

                // Bandeau statut global
                if (service.isConnected || service.isSimulation) ...[
                  _StatusBanner(
                    allOnline: allOnline,
                    offlineCount: offlineCount,
                    simulation: service.isSimulation,
                    thingCount: things.length,
                  ),
                  const SizedBox(height: 16),
                ],

                // État de chargement
                if (!service.isConnected && !service.isSimulation)
                  _Placeholder(
                    icon: Icons.cloud_off_rounded,
                    label: 'Non connecté à nymea',
                  )
                else if (things.isEmpty && !service.thingsLoaded)
                  const Padding(
                    padding: EdgeInsets.only(top: 60),
                    child: Center(
                      child: CircularProgressIndicator(
                          strokeWidth: 2, color: EtmTokens.green),
                    ),
                  )
                else if (things.isEmpty)
                  _Placeholder(
                    icon: Icons.devices_other_rounded,
                    label: 'Aucun appareil configuré',
                  )
                else
                  _CategoryGrid(
                    cats: cats,
                    grouped: grouped,
                    classes: classes,
                  ),
              ]),
            ),
          ),
        ],
      ),
    );
  }

  NymeaThingClass? _classFor(NymeaThing t, List<NymeaThingClass> cls) {
    try { return cls.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;
  }
}

// ─────────────────────────── Bandeau statut ────────────────────────────────────

class _StatusBanner extends StatelessWidget {
  final bool allOnline;
  final int offlineCount;
  final bool simulation;
  final int thingCount;

  const _StatusBanner({
    required this.allOnline,
    required this.offlineCount,
    required this.simulation,
    required this.thingCount,
  });

  @override
  Widget build(BuildContext context) {
    final Color dotColor;
    final String text;

    if (simulation) {
      dotColor = EtmTokens.amber;
      text = 'Mode simulation · $thingCount appareil(s) simulé(s)';
    } else if (allOnline) {
      dotColor = EtmTokens.green;
      text = 'Tous les appareils connectés · dernière synchro à l\'instant';
    } else if (offlineCount > 0) {
      dotColor = EtmTokens.orange;
      text = '$offlineCount appareil(s) hors ligne';
    } else {
      dotColor = EtmTokens.faint;
      text = 'Aucun appareil connecté';
    }

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
      decoration: BoxDecoration(
        color: EtmTokens.card,
        borderRadius: BorderRadius.circular(EtmTokens.radius),
        boxShadow: EtmTokens.cardShadow,
      ),
      child: Row(
        children: [
          Container(
            width: 8, height: 8,
            decoration: BoxDecoration(color: dotColor, shape: BoxShape.circle),
          ),
          const SizedBox(width: 10),
          Expanded(
            child: Text(text,
                style: EtmTokens.sans(size: 13, color: EtmTokens.muted)),
          ),
        ],
      ),
    );
  }
}

// ─────────────────────────── Grille intrinsèque ────────────────────────────────

class _CategoryGrid extends StatelessWidget {
  final List<ThingCategory> cats;
  final Map<ThingCategory, List<NymeaThing>> grouped;
  final List<NymeaThingClass> classes;

  const _CategoryGrid({
    required this.cats,
    required this.grouped,
    required this.classes,
  });

  @override
  Widget build(BuildContext context) {
    final rows = <Widget>[];
    for (int i = 0; i < cats.length; i += 2) {
      rows.add(
        Row(
          crossAxisAlignment: CrossAxisAlignment.start, // hauteur intrinsèque
          children: [
            Expanded(
              child: _CategoryCard(
                cat: cats[i],
                things: grouped[cats[i]] ?? [],
                classes: classes,
                onTap: () => _openCategory(context, cats[i], grouped[cats[i]] ?? [], classes),
              ),
            ),
            const SizedBox(width: 14),
            Expanded(
              child: i + 1 < cats.length
                  ? _CategoryCard(
                      cat: cats[i + 1],
                      things: grouped[cats[i + 1]] ?? [],
                      classes: classes,
                      onTap: () => _openCategory(
                          context, cats[i + 1], grouped[cats[i + 1]] ?? [], classes),
                    )
                  : const SizedBox(),
            ),
          ],
        ),
      );
      if (i + 2 < cats.length) rows.add(const SizedBox(height: 14));
    }
    return Column(children: rows);
  }

  void _openCategory(BuildContext context, ThingCategory cat,
      List<NymeaThing> things, List<NymeaThingClass> classes) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (_) => CategoryOverviewScreen(
          info: categoryInfoMap[cat]!,
          things: things,
          thingClasses: classes,
        ),
      ),
    );
  }
}

// ─────────────────────────── Carte catégorie ───────────────────────────────────

class _CategoryCard extends StatelessWidget {
  final ThingCategory cat;
  final List<NymeaThing> things;
  final List<NymeaThingClass> classes;
  final VoidCallback onTap;

  const _CategoryCard({
    required this.cat,
    required this.things,
    required this.classes,
    required this.onTap,
  });

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

  bool _isOnline(NymeaThing t) {
    final cls = _classFor(t);
    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? _value(NymeaThing t) {
    final cls = _classFor(t);
    final p   = cls?.primaryStateType;
    if (p == null) return null;
    return p.formatValue(t.stateValue(p.id));
  }

  @override
  Widget build(BuildContext context) {
    final info = categoryInfoMap[cat]!;
    final count = things.length;

    // Container en dehors de Material pour que l'ombre soit visible
    return Container(
      decoration: BoxDecoration(
        color: EtmTokens.card,
        borderRadius: BorderRadius.circular(EtmTokens.radius),
        boxShadow: EtmTokens.cardShadow,
      ),
      child: Material(
        color: Colors.transparent,
        borderRadius: BorderRadius.circular(EtmTokens.radius),
        child: InkWell(
          onTap: onTap,
          borderRadius: BorderRadius.circular(EtmTokens.radius),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            mainAxisSize: MainAxisSize.min,
            children: [
              // ── En-tête ────────────────────────────────────────────────────
              Padding(
                padding: const EdgeInsets.fromLTRB(14, 14, 14, 10),
                child: Row(
                  children: [
                    Container(
                      width: 36, height: 36,
                      decoration: BoxDecoration(
                        color: info.color.withValues(alpha: 0.12),
                        borderRadius: BorderRadius.circular(10),
                      ),
                      child: Icon(info.icon, color: info.color, size: 20),
                    ),
                    const SizedBox(width: 10),
                    Expanded(
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            info.label.toUpperCase(),
                            style: EtmTokens.sans(
                              size: 9,
                              weight: FontWeight.w700,
                              color: EtmTokens.navy.withValues(alpha: 0.6),
                              letterSpacing: 0.6,
                            ),
                            maxLines: 1,
                            overflow: TextOverflow.ellipsis,
                          ),
                          Text(
                            '$count appareil${count > 1 ? 's' : ''}',
                            style: EtmTokens.sans(size: 11, color: EtmTokens.muted),
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),

              // ── Séparateur coloré ──────────────────────────────────────────
              Container(height: 1, color: info.color.withValues(alpha: 0.20)),

              // ── Liste des things ───────────────────────────────────────────
              ...things.map((t) => _ThingRow(
                    thing: t,
                    value: _value(t),
                    isOnline: _isOnline(t),
                    color: info.color,
                    isLast: t == things.last,
                  )),
            ],
          ),
        ),
      ),
    );  // closes InkWell
  }   // closes build
}     // closes _CategoryCard

// ─────────────────────────── Ligne thing ───────────────────────────────────────

class _ThingRow extends StatelessWidget {
  final NymeaThing thing;
  final String? value;
  final bool isOnline;
  final Color color;
  final bool isLast;

  const _ThingRow({
    required this.thing,
    required this.value,
    required this.isOnline,
    required this.color,
    required this.isLast,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.fromLTRB(14, 9, 14, 9),
      decoration: BoxDecoration(
        border: isLast
            ? null
            : Border(bottom: BorderSide(color: EtmTokens.line)),
        borderRadius: isLast
            ? const BorderRadius.vertical(bottom: Radius.circular(EtmTokens.radius))
            : null,
      ),
      child: Row(
        children: [
          Container(
            width: 7, height: 7,
            decoration: BoxDecoration(
              color: isOnline ? color : EtmTokens.faint,
              shape: BoxShape.circle,
            ),
          ),
          const SizedBox(width: 8),
          Expanded(
            child: Text(
              thing.name,
              style: EtmTokens.sans(size: 12, weight: FontWeight.w500),
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            ),
          ),
          const SizedBox(width: 4),
          if (value != null)
            Text(
              value!,
              style: EtmTokens.mono(
                size: 12,
                weight: FontWeight.w700,
                color: isOnline ? color : EtmTokens.muted,
              ),
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
            )
          else
            Text(
              isOnline ? 'OK' : 'Veille',
              style: EtmTokens.sans(
                size: 12,
                color: isOnline ? color : EtmTokens.faint,
              ),
            ),
        ],
      ),
    );
  }
}

// ─────────────────────────── Placeholder ───────────────────────────────────────

class _Placeholder extends StatelessWidget {
  final IconData icon;
  final String label;
  const _Placeholder({required this.icon, required this.label});

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 80),
      child: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(icon, size: 56, color: EtmTokens.faint),
            const SizedBox(height: 14),
            Text(label, style: EtmTokens.sans(size: 15, color: EtmTokens.muted)),
          ],
        ),
      ),
    );
  }
}

// ─────────────────────────── ThingCard (compat 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, style: EtmTokens.sans(size: 14)),
      trailing: value != null
          ? Text(value, style: EtmTokens.mono(size: 13, color: categoryInfo.color))
          : null,
      onTap: onTap,
    );
  }
}