import 'dart:math' show min, max;
import 'package:fl_chart/fl_chart.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../models/nymea_models.dart';
import '../services/nymea_service.dart';
import '../theme/app_theme.dart';

// ─────────────────────────────────────────────────────────────────────────────
//  StateHistoryChart — graphique historique d'un état nymea
//
//  Utilise Logging.GetLogEntries (source: "state-{thingId}-{stateTypeName}")
//  Sélecteur de plage : 1H / 24H / 7J / 30J
// ─────────────────────────────────────────────────────────────────────────────

class StateHistoryChart extends StatefulWidget {
  final String thingId;
  final NymeaStateType stateType;
  final Color accentColor;

  const StateHistoryChart({
    super.key,
    required this.thingId,
    required this.stateType,
    required this.accentColor,
  });

  @override
  State<StateHistoryChart> createState() => _StateHistoryChartState();
}

class _StateHistoryChartState extends State<StateHistoryChart> {
  // Plages disponibles
  static const _ranges = [
    _Range('1H',  Duration(hours: 1),  'SampleRate1Min'),
    _Range('24H', Duration(hours: 24), 'SampleRate15Mins'),
    _Range('7J',  Duration(days: 7),   'SampleRate1Hour'),
    _Range('30J', Duration(days: 30),  'SampleRate3Hours'),
  ];

  int _rangeIdx = 1; // 24H par défaut
  List<HistoryEntry> _data = [];
  bool _loading = false;
  bool _noData = false;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) => _fetch());
  }

  Future<void> _fetch() async {
    if (!mounted || _loading) return;
    setState(() {
      _loading = true;
      _noData = false;
    });
    final range = _ranges[_rangeIdx];
    final now = DateTime.now();
    final from = now.subtract(range.duration);
    final service = context.read<NymeaService>();
    final data = await service.fetchHistory(
      thingId: widget.thingId,
      stateTypeName: widget.stateType.name,
      from: from,
      to: now,
      sampleRate: range.sampleRate,
    );
    if (!mounted) return;
    setState(() {
      _data = data;
      _loading = false;
      _noData = data.isEmpty;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.fromLTRB(16, 0, 16, 0),
      padding: const EdgeInsets.fromLTRB(14, 14, 14, 10),
      decoration: BoxDecoration(
        color: AppTheme.cardWhite,
        borderRadius: BorderRadius.circular(AppTheme.cornerRadius),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // ── En-tête : nom + sélecteur de plage ────────────────────────────
          Row(
            children: [
              Expanded(
                child: Text(
                  widget.stateType.displayName,
                  style: const TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w600,
                    color: AppTheme.textDark,
                  ),
                  overflow: TextOverflow.ellipsis,
                ),
              ),
              for (int i = 0; i < _ranges.length; i++)
                GestureDetector(
                  onTap: () {
                    if (_rangeIdx != i) {
                      setState(() => _rangeIdx = i);
                      _fetch();
                    }
                  },
                  child: AnimatedContainer(
                    duration: const Duration(milliseconds: 200),
                    padding:
                        const EdgeInsets.symmetric(horizontal: 7, vertical: 4),
                    margin: const EdgeInsets.only(left: 4),
                    decoration: BoxDecoration(
                      color: _rangeIdx == i
                          ? widget.accentColor
                          : widget.accentColor.withValues(alpha: 0.10),
                      borderRadius: BorderRadius.circular(6),
                    ),
                    child: Text(
                      _ranges[i].label,
                      style: TextStyle(
                        fontSize: 10,
                        fontWeight: FontWeight.w700,
                        color: _rangeIdx == i
                            ? Colors.white
                            : widget.accentColor,
                      ),
                    ),
                  ),
                ),
            ],
          ),

          const SizedBox(height: 12),

          // ── Zone du graphique ──────────────────────────────────────────────
          SizedBox(
            height: 130,
            child: _loading
                ? Center(
                    child: SizedBox(
                      width: 22,
                      height: 22,
                      child: CircularProgressIndicator(
                        strokeWidth: 2,
                        color: widget.accentColor,
                      ),
                    ),
                  )
                : _noData
                    ? const Center(
                        child: Text(
                          'Aucune donnée historique',
                          style: TextStyle(
                              color: AppTheme.textLight, fontSize: 12),
                        ),
                      )
                    : _buildChart(),
          ),
        ],
      ),
    );
  }

  Widget _buildChart() {
    if (_data.isEmpty) return const SizedBox.shrink();

    // Spots : x = index flottant, y = valeur de l'état
    final spots = <FlSpot>[];
    for (int i = 0; i < _data.length; i++) {
      spots.add(FlSpot(i.toDouble(), _data[i].value));
    }

    final minY = _data.map((e) => e.value).reduce(min);
    final maxY = _data.map((e) => e.value).reduce(max);
    final yPad = (maxY - minY) > 0 ? (maxY - minY) * 0.12 : 1.0;
    final yInterval = (maxY - minY) > 0 ? (maxY - minY) / 3 : 1.0;

    // Interval de l'axe X : afficher ~4 labels
    final xInterval =
        spots.length > 4 ? (spots.length / 4).ceilToDouble() : 1.0;

    final showDate = _rangeIdx >= 2; // 7J ou 30J → afficher jour/mois

    return LineChart(
      LineChartData(
        clipData: const FlClipData.all(),
        lineBarsData: [
          LineChartBarData(
            spots: spots,
            isCurved: true,
            curveSmoothness: 0.25,
            color: widget.accentColor,
            barWidth: 2,
            dotData: const FlDotData(show: false),
            belowBarData: BarAreaData(
              show: true,
              color: widget.accentColor.withValues(alpha: 0.08),
            ),
          ),
        ],
        minY: minY - yPad,
        maxY: maxY + yPad,
        gridData: FlGridData(
          show: true,
          drawVerticalLine: false,
          horizontalInterval: yInterval,
          getDrawingHorizontalLine: (_) => const FlLine(
            color: Color(0xFFEEEEEE),
            strokeWidth: 1,
          ),
        ),
        borderData: FlBorderData(show: false),
        titlesData: FlTitlesData(
          topTitles: const AxisTitles(
              sideTitles: SideTitles(showTitles: false)),
          rightTitles: const AxisTitles(
              sideTitles: SideTitles(showTitles: false)),
          // ── Axe Y ────────────────────────────────────────────────────────
          leftTitles: AxisTitles(
            sideTitles: SideTitles(
              showTitles: true,
              reservedSize: 46,
              interval: yInterval,
              getTitlesWidget: (v, meta) {
                // Formater sans répéter l'unité à chaque label
                final raw = widget.stateType.formatValue(v);
                return Padding(
                  padding: const EdgeInsets.only(right: 4),
                  child: Text(
                    raw,
                    style: const TextStyle(
                        fontSize: 8.5, color: AppTheme.textLight),
                    textAlign: TextAlign.right,
                  ),
                );
              },
            ),
          ),
          // ── Axe X ────────────────────────────────────────────────────────
          bottomTitles: AxisTitles(
            sideTitles: SideTitles(
              showTitles: true,
              reservedSize: 18,
              interval: xInterval,
              getTitlesWidget: (v, meta) {
                final idx = v.round();
                if (idx < 0 || idx >= _data.length) {
                  return const SizedBox.shrink();
                }
                final t = _data[idx].timestamp;
                final label = showDate
                    ? '${t.day}/${t.month}'
                    : '${t.hour.toString().padLeft(2, '0')}:'
                        '${t.minute.toString().padLeft(2, '0')}';
                return Text(
                  label,
                  style: const TextStyle(
                      fontSize: 8.5, color: AppTheme.textLight),
                );
              },
            ),
          ),
        ),
      ),
    );
  }
}

// ── Plage de temps + sampleRate associé ───────────────────────────────────────
class _Range {
  final String label;
  final Duration duration;
  final String sampleRate;

  const _Range(this.label, this.duration, this.sampleRate);
}