import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../providers/scheduler_provider.dart';
import '../../services/nymea_service.dart';
import '../../theme/app_theme.dart';
import '../../theme/etm_theme.dart';
import '../../widgets/pro_lock_badge.dart';

/// Écran "Scheduler & stratégie".
class SchedulerScreen extends StatefulWidget {
  const SchedulerScreen({super.key});

  @override
  State<SchedulerScreen> createState() => _SchedulerScreenState();
}

class _SchedulerScreenState extends State<SchedulerScreen> {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<SchedulerProvider>().load(context.read<NymeaService>());
    });
  }

  @override
  Widget build(BuildContext context) {
    final scheduler = context.watch<SchedulerProvider>();

    return Scaffold(
      backgroundColor: const Color(0xFFF0F2F5),
      appBar: AppBar(
        title: const Text('Scheduler & stratégie'),
        backgroundColor: Colors.white,
        foregroundColor: const Color(0xFF1A1A2E),
        elevation: 0,
      ),
      body: scheduler.loading
          ? const Center(child: CircularProgressIndicator())
          : ListView(
              padding: const EdgeInsets.all(16),
              children: [
                _StrategyCard(scheduler),
                const SizedBox(height: 12),
                _ConfigCard(scheduler),
                const SizedBox(height: 12),
                _StatusCard(scheduler),
              ],
            ),
    );
  }
}

// ── Carte stratégie ───────────────────────────────────────────────────────────
class _StrategyCard extends StatelessWidget {
  final SchedulerProvider scheduler;
  const _StrategyCard(this.scheduler);

  @override
  Widget build(BuildContext context) {
    return _Card(
      title: 'Stratégie active',
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          DropdownButtonFormField<SchedulerStrategy>(
            value: scheduler.strategy.isPro
                ? SchedulerStrategy.rulesBased
                : scheduler.strategy,
            decoration: InputDecoration(
              border: OutlineInputBorder(
                  borderRadius: BorderRadius.circular(12)),
              contentPadding: const EdgeInsets.symmetric(
                  horizontal: 14, vertical: 12),
            ),
            items: SchedulerStrategy.values.map((s) {
              return DropdownMenuItem(
                value: s.isPro ? null : s,
                enabled: !s.isPro,
                child: Row(
                  children: [
                    Text(s.label),
                    if (s.isPro) ...[
                      const SizedBox(width: 8),
                      const ProLockBadge(featureName: 'Stratégie AI'),
                    ],
                  ],
                ),
              );
            }).toList(),
            onChanged: (v) {
              if (v != null) {
                context
                    .read<SchedulerProvider>()
                    .setStrategy(v);
              }
            },
          ),
        ],
      ),
    );
  }
}

// ── Carte paramètres ──────────────────────────────────────────────────────────
class _ConfigCard extends StatelessWidget {
  final SchedulerProvider scheduler;
  const _ConfigCard(this.scheduler);

  @override
  Widget build(BuildContext context) {
    final cfg = scheduler.config;

    return _Card(
      title: 'Paramètres',
      child: Column(
        children: [
          _ConfigRow(
            label: 'Seuil prix recharge',
            value: cfg.priceThreshold,
            unit: '€/kWh',
            min: 0.01, max: 0.5, decimals: 3,
            onChanged: (v) => context
                .read<SchedulerProvider>()
                .updateConfig(cfg.copyWith(priceThreshold: v)),
          ),
          _ConfigRow(
            label: 'Surplus minimum',
            value: cfg.minSurplus,
            unit: 'W',
            min: 50, max: 2000,
            onChanged: (v) => context
                .read<SchedulerProvider>()
                .updateConfig(cfg.copyWith(minSurplus: v)),
          ),
          _ConfigRow(
            label: 'Horizon planification',
            value: cfg.planningHorizon.toDouble(),
            unit: 'h',
            min: 1, max: 72,
            onChanged: (v) => context
                .read<SchedulerProvider>()
                .updateConfig(cfg.copyWith(planningHorizon: v.toInt())),
          ),
          _ConfigRow(
            label: 'Recalcul toutes les',
            value: cfg.recalcInterval.toDouble(),
            unit: 'min',
            min: 5, max: 60,
            onChanged: (v) => context
                .read<SchedulerProvider>()
                .updateConfig(cfg.copyWith(recalcInterval: v.toInt())),
          ),
          _ConfigRow(
            label: 'Objectif autosuffisance',
            value: cfg.selfSufficiencyGoal,
            unit: '%',
            min: 0, max: 100,
            onChanged: (v) => context
                .read<SchedulerProvider>()
                .updateConfig(cfg.copyWith(selfSufficiencyGoal: v)),
          ),
        ],
      ),
    );
  }
}

class _ConfigRow extends StatefulWidget {
  final String  label;
  final double  value;
  final String  unit;
  final double  min;
  final double  max;
  final int     decimals;
  final ValueChanged<double> onChanged;

  const _ConfigRow({
    required this.label,
    required this.value,
    required this.unit,
    required this.min,
    required this.max,
    required this.onChanged,
    this.decimals = 0,
  });

  @override
  State<_ConfigRow> createState() => _ConfigRowState();
}

class _ConfigRowState extends State<_ConfigRow> {
  late TextEditingController _ctrl;

  @override
  void initState() {
    super.initState();
    _ctrl = TextEditingController(
        text: widget.value.toStringAsFixed(widget.decimals));
  }

  @override
  void didUpdateWidget(_ConfigRow old) {
    super.didUpdateWidget(old);
    final formatted = widget.value.toStringAsFixed(widget.decimals);
    if (_ctrl.text != formatted) _ctrl.text = formatted;
  }

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

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 12),
      child: Row(
        children: [
          Expanded(
            child: Text(widget.label,
                style: const TextStyle(fontSize: 13)),
          ),
          SizedBox(
            width: 80,
            child: TextFormField(
              controller: _ctrl,
              textAlign: TextAlign.center,
              keyboardType: const TextInputType.numberWithOptions(
                  decimal: true),
              decoration: InputDecoration(
                isDense: true,
                filled: true,
                fillColor: Colors.grey.shade50,
                border: OutlineInputBorder(
                    borderRadius: BorderRadius.circular(8)),
                contentPadding: const EdgeInsets.symmetric(
                    horizontal: 8, vertical: 8),
              ),
              onFieldSubmitted: (v) {
                final n = double.tryParse(v);
                if (n != null) {
                  widget.onChanged(n.clamp(widget.min, widget.max));
                }
              },
            ),
          ),
          const SizedBox(width: 6),
          Text(widget.unit,
              style: const TextStyle(
                  fontSize: 12, color: AppTheme.textLight)),
        ],
      ),
    );
  }
}

// ── Carte état du scheduler ───────────────────────────────────────────────────
class _StatusCard extends StatelessWidget {
  final SchedulerProvider scheduler;
  const _StatusCard(this.scheduler);

  @override
  Widget build(BuildContext context) {
    final state = scheduler.state;
    final statusColor = switch (state.status) {
      SchedulerStatus.ok       => AppTheme.primaryGreen,
      SchedulerStatus.degraded => Colors.orange,
      SchedulerStatus.error    => AppTheme.boostRed,
    };
    final statusLabel = switch (state.status) {
      SchedulerStatus.ok       => '✅ OK',
      SchedulerStatus.degraded => '⚠️ Dégradé',
      SchedulerStatus.error    => '❌ Erreur',
    };

    String _ago(DateTime? dt) {
      if (dt == null) return '—';
      final diff = DateTime.now().difference(dt);
      if (diff.inMinutes < 1) return 'à l\'instant';
      return 'il y a ${diff.inMinutes} min';
    }

    String _in(DateTime? dt) {
      if (dt == null) return '—';
      final diff = dt.difference(DateTime.now());
      if (diff.isNegative) return 'dépassé';
      return 'dans ${diff.inMinutes} min';
    }

    return _Card(
      title: 'État du scheduler',
      trailing: ElevatedButton.icon(
        icon: scheduler.loading
            ? const SizedBox(
                width: 14, height: 14,
                child: CircularProgressIndicator(
                    strokeWidth: 2, color: Colors.white))
            : const Icon(Icons.refresh_rounded, size: 16),
        label: const Text('Forcer recalcul'),
        style: ElevatedButton.styleFrom(
          backgroundColor: ETMTheme.accentColor,
          foregroundColor: Colors.white,
          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
          textStyle: const TextStyle(fontSize: 12),
          shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.circular(10)),
        ),
        onPressed: () => context
            .read<SchedulerProvider>()
            .forceRecalc(context.read<NymeaService>()),
      ),
      child: Column(
        children: [
          _StatusRow('Dernière planification', _ago(state.lastPlanning)),
          _StatusRow('Prochaine planification', _in(state.nextPlanning)),
          Row(
            children: [
              const Expanded(
                  child: Text('État', style: TextStyle(fontSize: 13))),
              Text(statusLabel,
                  style: TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                      color: statusColor)),
            ],
          ),
          if (state.reason.isNotEmpty) ...[
            const SizedBox(height: 6),
            Text(
              'Raison : ${state.reason}',
              style: const TextStyle(
                  fontSize: 12, color: AppTheme.textLight),
            ),
          ],
        ],
      ),
    );
  }
}

class _StatusRow extends StatelessWidget {
  final String label;
  final String value;
  const _StatusRow(this.label, this.value);

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(bottom: 6),
      child: Row(
        children: [
          Expanded(
              child: Text(label,
                  style: const TextStyle(fontSize: 13))),
          Text(value,
              style: const TextStyle(
                  fontSize: 13,
                  color: AppTheme.textLight)),
        ],
      ),
    );
  }
}

// ── Card générique ────────────────────────────────────────────────────────────
class _Card extends StatelessWidget {
  final String  title;
  final Widget  child;
  final Widget? trailing;

  const _Card({required this.title, required this.child, this.trailing});

  @override
  Widget build(BuildContext context) {
    return Card(
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(14)),
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              children: [
                Text(title,
                    style: const TextStyle(
                        fontWeight: FontWeight.bold, fontSize: 14)),
                const Spacer(),
                if (trailing != null) trailing!,
              ],
            ),
            const SizedBox(height: 14),
            child,
          ],
        ),
      ),
    );
  }
}