import 'package:flutter/material.dart';
import 'package:intaleq_maps/intaleq_maps.dart';
import '../models/angle_unit.dart';
import '../services/military_grid_utils.dart';
import '../services/offline_los_engine.dart';
import '../services/resection_calculator.dart';
import '../services/tactical_api_service.dart';

class TacticalLosSheet extends StatefulWidget {
  final LatLng observer;
  final LatLng target;
  final LatLng? currentGps;
  final AngleUnit angleUnit;
  final Function(LatLng newObserver, LatLng newTarget) onUpdateLocations;
  final ValueChanged<bool>? onVisibilityChanged;
  final ValueChanged<OfflineLosReport>? onReportGenerated;
  final VoidCallback onPickObserverOnMap;
  final VoidCallback onPickTargetOnMap;
  final VoidCallback onClose;

  const TacticalLosSheet({
    super.key,
    required this.observer,
    required this.target,
    this.currentGps,
    required this.angleUnit,
    required this.onUpdateLocations,
    this.onVisibilityChanged,
    this.onReportGenerated,
    required this.onPickObserverOnMap,
    required this.onPickTargetOnMap,
    required this.onClose,
  });

  @override
  State<TacticalLosSheet> createState() => _TacticalLosSheetState();
}

class _TacticalLosSheetState extends State<TacticalLosSheet> with SingleTickerProviderStateMixin {
  late TabController _tabController;

  // Controllers for Easting / Northing
  late TextEditingController _obsEastingCtrl;
  late TextEditingController _obsNorthingCtrl;
  late TextEditingController _tgtEastingCtrl;
  late TextEditingController _tgtNorthingCtrl;

  // Controllers for Lat / Lng
  late TextEditingController _obsLatCtrl;
  late TextEditingController _obsLngCtrl;
  late TextEditingController _tgtLatCtrl;
  late TextEditingController _tgtLngCtrl;

  // Optic Heights (ارتفاع الراصد والهدف عن سطح الأرض)
  double _observerHeightM = 2.0;
  double _targetHeightM = 2.0;

  // Calculation Results (Hybrid Server + Sovereign Offline DEM Engine)
  OfflineLosReport? _losReport;
  bool _isCalculating = false;
  int? _inspectedSampleIndex;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 2, vsync: this);

    final obsMil = MilitaryGridUtils.fromLatLng(widget.observer);
    final tgtMil = MilitaryGridUtils.fromLatLng(widget.target);

    _obsEastingCtrl = TextEditingController(text: obsMil.eastingStr);
    _obsNorthingCtrl = TextEditingController(text: obsMil.northingStr);
    _tgtEastingCtrl = TextEditingController(text: tgtMil.eastingStr);
    _tgtNorthingCtrl = TextEditingController(text: tgtMil.northingStr);

    _obsLatCtrl = TextEditingController(text: widget.observer.latitude.toStringAsFixed(6));
    _obsLngCtrl = TextEditingController(text: widget.observer.longitude.toStringAsFixed(6));
    _tgtLatCtrl = TextEditingController(text: widget.target.latitude.toStringAsFixed(6));
    _tgtLngCtrl = TextEditingController(text: widget.target.longitude.toStringAsFixed(6));

    _losReport = OfflineLosEngine.calculate(
      observer: widget.observer,
      target: widget.target,
      observerHeightM: _observerHeightM,
      targetHeightM: _targetHeightM,
    );

    _calculateLos(widget.observer, widget.target);
  }

  @override
  void didUpdateWidget(covariant TacticalLosSheet oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.observer != widget.observer || oldWidget.target != widget.target) {
      final obsMil = MilitaryGridUtils.fromLatLng(widget.observer);
      final tgtMil = MilitaryGridUtils.fromLatLng(widget.target);

      _obsEastingCtrl.text = obsMil.eastingStr;
      _obsNorthingCtrl.text = obsMil.northingStr;
      _tgtEastingCtrl.text = tgtMil.eastingStr;
      _tgtNorthingCtrl.text = tgtMil.northingStr;

      _obsLatCtrl.text = widget.observer.latitude.toStringAsFixed(6);
      _obsLngCtrl.text = widget.observer.longitude.toStringAsFixed(6);
      _tgtLatCtrl.text = widget.target.latitude.toStringAsFixed(6);
      _tgtLngCtrl.text = widget.target.longitude.toStringAsFixed(6);

      _calculateLos(widget.observer, widget.target);
    }
  }

  @override
  void dispose() {
    _tabController.dispose();
    _obsEastingCtrl.dispose();
    _obsNorthingCtrl.dispose();
    _tgtEastingCtrl.dispose();
    _tgtNorthingCtrl.dispose();
    _obsLatCtrl.dispose();
    _obsLngCtrl.dispose();
    _tgtLatCtrl.dispose();
    _tgtLngCtrl.dispose();
    super.dispose();
  }

  Future<void> _calculateLos(LatLng obs, LatLng tgt) async {
    setState(() => _isCalculating = true);

    try {
      final report = await TacticalApiService.calculateHybridLineOfSight(
        observer: obs,
        target: tgt,
        observerHeight: _observerHeightM,
        targetHeight: _targetHeightM,
      );

      if (mounted) {
        setState(() {
          _losReport = report;
          _isCalculating = false;
        });
      }
      widget.onVisibilityChanged?.call(report.isDirectlyVisible);
      widget.onReportGenerated?.call(report);
    } catch (e) {
      debugPrint('LOS calculation error: $e');
      if (mounted) {
        setState(() => _isCalculating = false);
      }
    }
  }

  void _applyManualCoordinates() {
    LatLng newObs = widget.observer;
    LatLng newTgt = widget.target;

    if (_tabController.index == 0) {
      // UTM Easting/Northing
      final obsE = double.tryParse(_obsEastingCtrl.text) ?? 0;
      final obsN = double.tryParse(_obsNorthingCtrl.text) ?? 0;
      final tgtE = double.tryParse(_tgtEastingCtrl.text) ?? 0;
      final tgtN = double.tryParse(_tgtNorthingCtrl.text) ?? 0;

      if (obsE > 100000 && obsN > 1000000) {
        newObs = MilitaryGridUtils.toLatLng(easting: obsE, northing: obsN);
      }
      if (tgtE > 100000 && tgtN > 1000000) {
        newTgt = MilitaryGridUtils.toLatLng(easting: tgtE, northing: tgtN);
      }
    } else {
      // Decimal Lat/Lng
      final obsLat = double.tryParse(_obsLatCtrl.text);
      final obsLng = double.tryParse(_obsLngCtrl.text);
      final tgtLat = double.tryParse(_tgtLatCtrl.text);
      final tgtLng = double.tryParse(_tgtLngCtrl.text);

      if (obsLat != null && obsLng != null) newObs = LatLng(obsLat, obsLng);
      if (tgtLat != null && tgtLng != null) newTgt = LatLng(tgtLat, tgtLng);
    }

    widget.onUpdateLocations(newObs, newTgt);
    _calculateLos(newObs, newTgt);
  }

  @override
  Widget build(BuildContext context) {
    final isVisible = _losReport?.isDirectlyVisible ?? true;
    final distanceMeters = _losReport?.totalDistanceM ??
        ResectionCalculator.haversineDistance(
          widget.observer.latitude,
          widget.observer.longitude,
          widget.target.latitude,
          widget.target.longitude,
        );

    final azimuthDeg = _losReport?.azimuthDeg ??
        ResectionCalculator.calculateBearing(
          widget.observer.latitude,
          widget.observer.longitude,
          widget.target.latitude,
          widget.target.longitude,
        );

    final maxElev = _losReport?.maxElevationM ?? 950.0;

    return Container(
      constraints: BoxConstraints(
        maxHeight: MediaQuery.of(context).size.height * 0.88,
      ),
      padding: const EdgeInsets.all(16),
      decoration: const BoxDecoration(
        color: Color(0xFF090E1A),
        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
        border: Border(top: BorderSide(color: Color(0xFF0071E3), width: 2.5)),
        boxShadow: [BoxShadow(color: Colors.black87, blurRadius: 30)],
      ),
      child: SingleChildScrollView(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Handle bar
            Center(
              child: Container(
                width: 40,
                height: 4,
                margin: const EdgeInsets.only(bottom: 10),
                decoration: BoxDecoration(
                  color: Colors.white24,
                  borderRadius: BorderRadius.circular(2),
                ),
              ),
            ),

            // Header Bar
            Row(
              children: [
                Expanded(
                  child: Row(
                    children: [
                      Container(
                        padding: const EdgeInsets.all(7),
                        decoration: BoxDecoration(
                          color: isVisible ? const Color(0x3322C55E) : const Color(0x33EF4444),
                          borderRadius: BorderRadius.circular(8),
                          border: Border.all(
                            color: isVisible ? const Color(0xFF22C55E) : const Color(0xFFEF4444),
                          ),
                        ),
                        child: Icon(
                          isVisible ? Icons.visibility : Icons.visibility_off,
                          color: isVisible ? const Color(0xFF4ADE80) : const Color(0xFFF87171),
                          size: 22,
                        ),
                      ),
                      const SizedBox(width: 10),
                      Expanded(
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            const Text(
                              'منظومة تحليل تبادل الرؤية العسكري (LOS)',
                              style: TextStyle(color: Colors.white, fontSize: 12.5, fontWeight: FontWeight.bold),
                              overflow: TextOverflow.ellipsis,
                            ),
                            Row(
                              children: [
                                Flexible(
                                  child: Text(
                                    isVisible
                                        ? '🟢 خط الرؤية مكشوف وسالك (Clear)'
                                        : '🔴 خط الرؤية محجوب بتضاريس (Blocked)',
                                    style: TextStyle(
                                      color: isVisible ? const Color(0xFF4ADE80) : const Color(0xFFF87171),
                                      fontSize: 10.5,
                                      fontWeight: FontWeight.w600,
                                    ),
                                    overflow: TextOverflow.ellipsis,
                                  ),
                                ),
                                if (_isCalculating) ...[
                                  const SizedBox(width: 6),
                                  const SizedBox(
                                    width: 10,
                                    height: 10,
                                    child: CircularProgressIndicator(strokeWidth: 2, color: Color(0xFF38BDF8)),
                                  ),
                                ],
                              ],
                            ),
                          ],
                        ),
                      ),
                    ],
                  ),
                ),
                IconButton(
                  onPressed: widget.onClose,
                  icon: const Icon(Icons.close, color: Colors.white70, size: 20),
                ),
              ],
            ),

            const SizedBox(height: 10),

            // Coordinates Tabs: [شرقيات / شماليات UTM-36N] vs [درجات Lat/Lng]
            Container(
              height: 32,
              decoration: BoxDecoration(
                color: const Color(0xFF1E293B),
                borderRadius: BorderRadius.circular(10),
              ),
              child: TabBar(
                controller: _tabController,
                indicator: BoxDecoration(
                  color: const Color(0xFF0071E3),
                  borderRadius: BorderRadius.circular(10),
                ),
                labelColor: Colors.white,
                unselectedLabelColor: const Color(0xFF94A3B8),
                labelStyle: const TextStyle(fontSize: 10.5, fontWeight: FontWeight.bold),
                tabs: const [
                  Tab(text: 'إحداثيات عسكرية (شرقيات / شماليات UTM)'),
                  Tab(text: 'درجات جغرافية (WGS84 Lat/Lng)'),
                ],
              ),
            ),

            const SizedBox(height: 10),

            // Coordinates Input Fields Table
            SizedBox(
              height: 95,
              child: TabBarView(
                controller: _tabController,
                children: [
                  // 1. Military UTM Easting / Northing Table
                  Row(
                    children: [
                      // Observer Card
                      Expanded(
                        child: Container(
                          padding: const EdgeInsets.all(7),
                          decoration: BoxDecoration(
                            color: const Color(0xFF0F172A),
                            borderRadius: BorderRadius.circular(10),
                            border: Border.all(color: const Color(0x3338BDF8)),
                          ),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Row(
                                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                children: [
                                  const Text('🔴 الراصد (Observer)', style: TextStyle(color: Color(0xFF38BDF8), fontSize: 10.5, fontWeight: FontWeight.bold)),
                                  InkWell(
                                    onTap: widget.onPickObserverOnMap,
                                    child: const Icon(Icons.touch_app, size: 15, color: Color(0xFF38BDF8)),
                                  ),
                                ],
                              ),
                              const SizedBox(height: 2),
                              Row(
                                children: [
                                  Expanded(
                                    child: TextField(
                                      controller: _obsEastingCtrl,
                                      keyboardType: TextInputType.number,
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'شرقيات E',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                  const SizedBox(width: 4),
                                  Expanded(
                                    child: TextField(
                                      controller: _obsNorthingCtrl,
                                      keyboardType: TextInputType.number,
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'شماليات N',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                ],
                              ),
                            ],
                          ),
                        ),
                      ),
                      const SizedBox(width: 8),
                      // Target Card
                      Expanded(
                        child: Container(
                          padding: const EdgeInsets.all(7),
                          decoration: BoxDecoration(
                            color: const Color(0xFF0F172A),
                            borderRadius: BorderRadius.circular(10),
                            border: Border.all(color: const Color(0x33F59E0B)),
                          ),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              Row(
                                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                                children: [
                                  const Text('🎯 الهدف (Target)', style: TextStyle(color: Color(0xFFF59E0B), fontSize: 10.5, fontWeight: FontWeight.bold)),
                                  InkWell(
                                    onTap: widget.onPickTargetOnMap,
                                    child: const Icon(Icons.touch_app, size: 15, color: Color(0xFFF59E0B)),
                                  ),
                                ],
                              ),
                              const SizedBox(height: 2),
                              Row(
                                children: [
                                  Expanded(
                                    child: TextField(
                                      controller: _tgtEastingCtrl,
                                      keyboardType: TextInputType.number,
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'شرقيات E',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                  const SizedBox(width: 4),
                                  Expanded(
                                    child: TextField(
                                      controller: _tgtNorthingCtrl,
                                      keyboardType: TextInputType.number,
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'شماليات N',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                ],
                              ),
                            ],
                          ),
                        ),
                      ),
                    ],
                  ),

                  // 2. Lat / Lng Table
                  Row(
                    children: [
                      // Observer Card
                      Expanded(
                        child: Container(
                          padding: const EdgeInsets.all(7),
                          decoration: BoxDecoration(
                            color: const Color(0xFF0F172A),
                            borderRadius: BorderRadius.circular(10),
                            border: Border.all(color: const Color(0x3338BDF8)),
                          ),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              const Text('🔴 الراصد (Lat/Lng)', style: TextStyle(color: Color(0xFF38BDF8), fontSize: 10.5, fontWeight: FontWeight.bold)),
                              const SizedBox(height: 2),
                              Row(
                                children: [
                                  Expanded(
                                    child: TextField(
                                      controller: _obsLatCtrl,
                                      keyboardType: const TextInputType.numberWithOptions(decimal: true),
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'خط العرض Lat',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                  const SizedBox(width: 4),
                                  Expanded(
                                    child: TextField(
                                      controller: _obsLngCtrl,
                                      keyboardType: const TextInputType.numberWithOptions(decimal: true),
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'خط الطول Lng',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                ],
                              ),
                            ],
                          ),
                        ),
                      ),
                      const SizedBox(width: 8),
                      // Target Card
                      Expanded(
                        child: Container(
                          padding: const EdgeInsets.all(7),
                          decoration: BoxDecoration(
                            color: const Color(0xFF0F172A),
                            borderRadius: BorderRadius.circular(10),
                            border: Border.all(color: const Color(0x33F59E0B)),
                          ),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.start,
                            children: [
                              const Text('🎯 الهدف (Lat/Lng)', style: TextStyle(color: Color(0xFFF59E0B), fontSize: 10.5, fontWeight: FontWeight.bold)),
                              const SizedBox(height: 2),
                              Row(
                                children: [
                                  Expanded(
                                    child: TextField(
                                      controller: _tgtLatCtrl,
                                      keyboardType: const TextInputType.numberWithOptions(decimal: true),
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'خط العرض Lat',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                  const SizedBox(width: 4),
                                  Expanded(
                                    child: TextField(
                                      controller: _tgtLngCtrl,
                                      keyboardType: const TextInputType.numberWithOptions(decimal: true),
                                      style: const TextStyle(color: Colors.white, fontSize: 11),
                                      decoration: const InputDecoration(
                                        labelText: 'خط الطول Lng',
                                        labelStyle: TextStyle(fontSize: 9, color: Color(0xFF94A3B8)),
                                        isDense: true,
                                        contentPadding: EdgeInsets.symmetric(horizontal: 4, vertical: 4),
                                      ),
                                      onSubmitted: (_) => _applyManualCoordinates(),
                                    ),
                                  ),
                                ],
                              ),
                            ],
                          ),
                        ),
                      ),
                    ],
                  ),
                ],
              ),
            ),

            const SizedBox(height: 8),

            // Optic Heights Adjustment (ارتفاع البصريات وسواري الرصد)
            Container(
              padding: const EdgeInsets.all(16),
              decoration: BoxDecoration(
                color: const Color(0xFF1E293B),
                borderRadius: BorderRadius.circular(10),
                border: Border.all(color: Colors.white10),
              ),
              child: Row(
                children: [
                  const Icon(Icons.height, size: 14, color: Color(0xFF38BDF8)),
                  const SizedBox(width: 6),
                  const Text('ارتفاع الرصد والهدف:', style: TextStyle(color: Color(0xFF94A3B8), fontSize: 10)),
                  const Spacer(),
                  _buildHeightChip('راصد +${_observerHeightM.round()}م', _observerHeightM, (h) {
                    setState(() => _observerHeightM = h);
                    _calculateLos(widget.observer, widget.target);
                  }),
                  const SizedBox(width: 6),
                  _buildHeightChip('هدف +${_targetHeightM.round()}م', _targetHeightM, (h) {
                    setState(() => _targetHeightM = h);
                    _calculateLos(widget.observer, widget.target);
                  }),
                ],
              ),
            ),

            const SizedBox(height: 10),

            // ── Tactical Elevation Profile & Intervisibility Cross-Section Chart ──
            if (_losReport != null && _losReport!.profile.length > 1) ...[
              _LosProfileChart(
                report: _losReport!,
                visible: isVisible,
                angleUnit: widget.angleUnit,
                selectedIndex: _inspectedSampleIndex,
                onHoverSample: (idx) => setState(() => _inspectedSampleIndex = idx),
              ),
              if (_inspectedSampleIndex != null && _inspectedSampleIndex! < _losReport!.profile.length) ...[
                const SizedBox(height: 6),
                _buildSampleInspectorCard(_losReport!.profile[_inspectedSampleIndex!]),
              ],
            ],

            const SizedBox(height: 10),

            // Tactical Metrics Data Summary
            Container(
              padding: const EdgeInsets.all(16),
              decoration: BoxDecoration(
                color: const Color(0xFF1E293B),
                borderRadius: BorderRadius.circular(12),
                border: Border.all(color: const Color(0x330071E3)),
              ),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceAround,
                children: [
                  _buildMetricItem(
                    'المسافة المباشرة',
                    distanceMeters >= 1000
                        ? '${(distanceMeters / 1000.0).toStringAsFixed(2)} كم'
                        : '${distanceMeters.toStringAsFixed(0)} م',
                    Icons.straighten,
                  ),
                  _buildMetricItem(
                    'السمت التكتيكي',
                    AngleFormatter.format(azimuthDeg, widget.angleUnit, includeLabel: true),
                    Icons.explore,
                  ),
                  _buildMetricItem(
                    'أعلى تضاريس',
                    '${maxElev.round()} م',
                    Icons.terrain,
                  ),
                ],
              ),
            ),

            if (_losReport != null) ...[
              const SizedBox(height: 8),
              // Ground & air / LOS geometry detail row
              Container(
                padding: const EdgeInsets.all(16),
                decoration: BoxDecoration(
                  color: const Color(0xFF0F172A),
                  borderRadius: BorderRadius.circular(12),
                  border: Border.all(
                    color: isVisible ? const Color(0x3322C55E) : const Color(0x44EF4444),
                  ),
                ),
                child: Column(
                  children: [
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceAround,
                      children: [
                        _buildMetricItem(
                          'ارتفاع الراصد الكلي',
                          '${_losReport!.observerTotalElevM.round()} م',
                          Icons.height,
                        ),
                        _buildMetricItem(
                          'ارتفاع الهدف الكلي',
                          '${_losReport!.targetTotalElevM.round()} م',
                          Icons.track_changes,
                        ),
                        _buildMetricItem(
                          'السمت (NATO / Soviet)',
                          '${_losReport!.azimuthMilsNato.round()} ₥ / ${_losReport!.azimuthMilsSoviet.round()} ₥',
                          Icons.explore,
                        ),
                      ],
                    ),
                    const SizedBox(height: 8),
                    Row(
                      mainAxisAlignment: MainAxisAlignment.spaceAround,
                      children: [
                        _buildMetricItem(
                          'زاوية ارتفاع الرصد',
                          '${_losReport!.verticalAngleDeg.toStringAsFixed(2)}° (${_losReport!.verticalAngleMils.toStringAsFixed(1)} ₥)',
                          Icons.vertical_align_top,
                        ),
                        _buildMetricItem(
                          'منطقة ميتة',
                          '${_losReport!.deadGroundPercent}%',
                          Icons.block,
                        ),
                        _buildMetricItem(
                          'أدنى ارتفاع',
                          '${_losReport!.minElevationM.round()} م',
                          Icons.arrow_downward,
                        ),
                      ],
                    ),
                    if (_losReport!.highestObstacle != null) ...[
                      const SizedBox(height: 8),
                      Container(
                        padding: const EdgeInsets.all(8),
                        decoration: BoxDecoration(
                          color: const Color(0x22EF4444),
                          borderRadius: BorderRadius.circular(8),
                          border: Border.all(color: const Color(0x55EF4444)),
                        ),
                        child: Row(
                          children: [
                            const Icon(Icons.warning_amber_rounded, size: 16, color: Color(0xFFF87171)),
                            const SizedBox(width: 8),
                            Expanded(
                              child: Text(
                                'نقطة الحجب القصوى: ارتفاع ${_losReport!.highestObstacle!.elevationM.round()}م على بعد ${_losReport!.highestObstacle!.distanceM.round()}م (اختراق شعاع الرؤية بمقدار +${_losReport!.highestObstacle!.excessM.toStringAsFixed(1)}م)',
                                style: const TextStyle(
                                  color: Color(0xFFF87171),
                                  fontSize: 10.5,
                                  fontWeight: FontWeight.w600,
                                ),
                              ),
                            ),
                          ],
                        ),
                      ),
                    ],
                  ],
                ),
              ),
            ],

            const SizedBox(height: 12),

            // Action Buttons
            Row(
              children: [
                Expanded(
                  child: ElevatedButton.icon(
                    onPressed: _applyManualCoordinates,
                    icon: const Icon(Icons.refresh, size: 16),
                    label: const Text('تطبيق وإعادة حساب الرؤية', style: TextStyle(fontSize: 12, fontWeight: FontWeight.bold)),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: const Color(0xFF0071E3),
                      foregroundColor: Colors.white,
                      padding: const EdgeInsets.all(16),
                      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
                    ),
                  ),
                ),
                if (widget.currentGps != null) ...[
                  const SizedBox(width: 8),
                  OutlinedButton.icon(
                    onPressed: () {
                      widget.onUpdateLocations(widget.currentGps!, widget.target);
                    },
                    icon: const Icon(Icons.my_location, size: 16),
                    label: const Text('موقعي الحالي', style: TextStyle(fontSize: 11)),
                    style: OutlinedButton.styleFrom(
                      foregroundColor: const Color(0xFF38BDF8),
                      side: const BorderSide(color: Color(0xFF0071E3)),
                      padding: const EdgeInsets.all(16),
                      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(10)),
                    ),
                  ),
                ],
              ],
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildHeightChip(String label, double currentHeight, Function(double) onSelected) {
    return PopupMenuButton<double>(
      initialValue: currentHeight,
      onSelected: onSelected,
      color: const Color(0xFF1E293B),
      itemBuilder: (ctx) => [
        const PopupMenuItem(value: 2.0, child: Text('رصد فردي (2 متر)', style: TextStyle(color: Colors.white, fontSize: 11))),
        const PopupMenuItem(value: 5.0, child: Text('برج مركبة / سارية (5 متر)', style: TextStyle(color: Colors.white, fontSize: 11))),
        const PopupMenuItem(value: 10.0, child: Text('برج مراقبة ميداني (10 متر)', style: TextStyle(color: Colors.white, fontSize: 11))),
        const PopupMenuItem(value: 25.0, child: Text('منطاد استطلاع / درون (25 متر)', style: TextStyle(color: Colors.white, fontSize: 11))),
      ],
      child: Container(
        padding: const EdgeInsets.all(16),
        decoration: BoxDecoration(
          color: const Color(0xFF0071E3).withValues(alpha: 0.3),
          borderRadius: BorderRadius.circular(6),
          border: Border.all(color: const Color(0xFF0071E3)),
        ),
        child: Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Text(label, style: const TextStyle(color: Color(0xFF38BDF8), fontSize: 10, fontWeight: FontWeight.bold)),
            const SizedBox(width: 3),
            const Icon(Icons.arrow_drop_down, size: 14, color: Color(0xFF38BDF8)),
          ],
        ),
      ),
    );
  }

  Widget _buildSampleInspectorCard(OfflineLosSample s) {
    final mil = MilitaryGridUtils.fromLatLng(LatLng(s.lat, s.lng));
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF1E293B),
        borderRadius: BorderRadius.circular(8),
        border: Border.all(color: s.isBlocked ? const Color(0xFFEF4444) : const Color(0xFF22C55E)),
      ),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text('محطة عند: ${s.distanceM.round()}م', style: const TextStyle(color: Colors.white70, fontSize: 10)),
          Text('تضاريس: ${s.groundElevationM.round()}م', style: const TextStyle(color: Color(0xFF38BDF8), fontSize: 10, fontWeight: FontWeight.bold)),
          Text('شعاع: ${s.rayHeightM.round()}م', style: const TextStyle(color: Color(0xFFF59E0B), fontSize: 10)),
          Text('خلوص: ${s.clearanceM >= 0 ? "+${s.clearanceM.toStringAsFixed(1)}" : s.clearanceM.toStringAsFixed(1)}م',
              style: TextStyle(color: s.clearanceM >= 0 ? const Color(0xFF4ADE80) : const Color(0xFFF87171), fontSize: 10, fontWeight: FontWeight.bold)),
          Text(mil.shortGrid, style: const TextStyle(color: Colors.white54, fontSize: 9)),
        ],
      ),
    );
  }

  Widget _buildMetricItem(String label, String val, IconData icon) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      children: [
        Row(
          mainAxisSize: MainAxisSize.min,
          children: [
            Icon(icon, size: 12, color: const Color(0xFF94A3B8)),
            const SizedBox(width: 4),
            Text(label, style: const TextStyle(color: Color(0xFF94A3B8), fontSize: 9.5)),
          ],
        ),
        const SizedBox(height: 3),
        Text(
          val,
          style: const TextStyle(color: Colors.white, fontSize: 11.5, fontWeight: FontWeight.bold),
        ),
      ],
    );
  }
}

/// Tactical terrain elevation profile chart with intervisibility ray & obstacle callout.
class _LosProfileChart extends StatelessWidget {
  final OfflineLosReport report;
  final bool visible;
  final AngleUnit angleUnit;
  final int? selectedIndex;
  final Function(int?) onHoverSample;

  const _LosProfileChart({
    required this.report,
    required this.visible,
    required this.angleUnit,
    this.selectedIndex,
    required this.onHoverSample,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.fromLTRB(6, 8, 6, 6),
      decoration: BoxDecoration(
        color: const Color(0xFF0F172A),
        borderRadius: BorderRadius.circular(12),
        border: Border.all(color: const Color(0x330071E3)),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Padding(
            padding: const EdgeInsets.all(16),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.start,
              children: [
                Container(
                  width: 8,
                  height: 8,
                  decoration: BoxDecoration(
                    color: visible ? const Color(0xFF22C55E) : const Color(0xFFEF4444),
                    shape: BoxShape.circle,
                  ),
                ),
                const SizedBox(width: 6),
                Text(
                  visible ? 'مقطع التضاريس وشعاع الرؤية المباشر' : 'مقطع التضاريس مع العائق الجبلي',
                  style: TextStyle(
                    color: visible ? const Color(0xFF4ADE80) : const Color(0xFFF87171),
                    fontSize: 11,
                    fontWeight: FontWeight.bold,
                  ),
                ),
                const Spacer(),
                Text(
                  '${(report.totalDistanceM / 1000).toStringAsFixed(1)} كم • ${report.azimuthDeg.toStringAsFixed(1)}°',
                  style: const TextStyle(color: Color(0xFF94A3B8), fontSize: 10, fontWeight: FontWeight.w600),
                ),
              ],
            ),
          ),
          const SizedBox(height: 6),
          GestureDetector(
            onHorizontalDragUpdate: (details) {
              final box = context.findRenderObject() as RenderBox?;
              if (box != null) {
                final localX = details.localPosition.dx;
                final width = box.size.width;
                final fraction = (localX / width).clamp(0.0, 1.0);
                final idx = (fraction * (report.profile.length - 1)).round();
                onHoverSample(idx);
              }
            },
            onTapDown: (details) {
              final box = context.findRenderObject() as RenderBox?;
              if (box != null) {
                final localX = details.localPosition.dx;
                final width = box.size.width;
                final fraction = (localX / width).clamp(0.0, 1.0);
                final idx = (fraction * (report.profile.length - 1)).round();
                onHoverSample(idx);
              }
            },
            child: CustomPaint(
              painter: _LosProfilePainter(
                report: report,
                clear: visible,
                selectedIndex: selectedIndex,
              ),
              size: const Size(double.infinity, 115),
            ),
          ),
        ],
      ),
    );
  }
}

/// Paints the terrain (ground), curvature sagitta, sight ray, obstacle callout, and dead ground.
class _LosProfilePainter extends CustomPainter {
  final OfflineLosReport report;
  final bool clear;
  final int? selectedIndex;

  _LosProfilePainter({
    required this.report,
    required this.clear,
    this.selectedIndex,
  });

  @override
  void paint(Canvas canvas, Size size) {
    final w = size.width;
    final h = size.height;
    const pad = 8.0;
    final samples = report.profile;

    if (samples.isEmpty) return;

    double minE = double.infinity;
    double maxE = -double.infinity;
    for (final s in samples) {
      if (s.groundElevationM < minE) minE = s.groundElevationM;
      if (s.groundElevationM > maxE) maxE = s.groundElevationM;
      if (s.rayHeightM > maxE) maxE = s.rayHeightM;
      if (s.rayHeightM < minE) minE = s.rayHeightM;
    }
    if ((maxE - minE).abs() < 1.0) {
      maxE = minE + 10.0;
    }
    minE -= 15.0; // Margin below
    maxE += 20.0; // Margin above

    double x(num j) => pad + (w - 2 * pad) * (j.toDouble() / (samples.length - 1));
    double y(num e) => h - pad - (h - 2 * pad) * ((e.toDouble() - minE) / (maxE - minE));

    // 1. Draw Grid Lines & Elevation scale with Text Labels
    final gridPaint = Paint()
      ..color = Colors.white12
      ..strokeWidth = 0.8;
    
    void drawGridLevel(double elev) {
      final yPos = y(elev);
      canvas.drawLine(Offset(pad, yPos), Offset(w - pad, yPos), gridPaint);
      
      final textPainter = TextPainter(
        text: TextSpan(
          text: '${elev.round()}م',
          style: const TextStyle(color: Colors.white38, fontSize: 8.5),
        ),
        textDirection: TextDirection.rtl,
      )..layout();
      textPainter.paint(canvas, Offset(pad + 2, yPos - 11));
    }

    final midE = (minE + maxE) / 2;
    drawGridLevel(minE + 15);
    drawGridLevel(midE);
    drawGridLevel(maxE - 15);

    // 2. Ground Profile Fill & Stroke
    final groundPath = Path()..moveTo(x(0), y(samples.first.groundElevationM));
    for (int i = 1; i < samples.length; i++) {
      groundPath.lineTo(x(i), y(samples[i].groundElevationM));
    }
    groundPath.lineTo(x(samples.length - 1), h);
    groundPath.lineTo(x(0), h);
    groundPath.close();

    final groundGradient = LinearGradient(
      begin: Alignment.topCenter,
      end: Alignment.bottomCenter,
      colors: [
        const Color(0xFF334155),
        const Color(0xFF0F172A),
      ],
    );
    final groundPaint = Paint()
      ..style = PaintingStyle.fill
      ..shader = groundGradient.createShader(Rect.fromLTWH(0, 0, w, h));
    canvas.drawPath(groundPath, groundPaint);

    final ridgePaint = Paint()
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2.0
      ..color = const Color(0xFF38BDF8);
    final ridgePath = Path()..moveTo(x(0), y(samples.first.groundElevationM));
    for (int i = 1; i < samples.length; i++) {
      ridgePath.lineTo(x(i), y(samples[i].groundElevationM));
    }
    canvas.drawPath(ridgePath, ridgePaint);

    // 3. Highlight Dead Ground (المنطقة الميتة)
    for (int i = 0; i < samples.length - 1; i++) {
      if (!samples[i].isVisible) {
        final dgRect = Rect.fromLTRB(x(i), y(samples[i].groundElevationM), x(i + 1), h - pad);
        canvas.drawRect(dgRect, Paint()..color = const Color(0x33EF4444));
      }
    }

    // 4. Line of Sight Straight Ray
    final rayPaint = Paint()
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2.4
      ..color = clear ? const Color(0xFF22C55E) : const Color(0xFFEF4444);
    final rayPath = Path()..moveTo(x(0), y(samples.first.rayHeightM));
    for (int i = 1; i < samples.length; i++) {
      rayPath.lineTo(x(i), y(samples[i].rayHeightM));
    }
    canvas.drawPath(rayPath, rayPaint);

    // 5. Highest Obstruction Marker & Deficit Line
    final obs = report.highestObstacle;
    if (obs != null && !clear) {
      final dobj = obs.distanceM;
      final maxD = report.totalDistanceM > 0 ? report.totalDistanceM : 1.0;
      final fx = pad + (w - 2 * pad) * (dobj / maxD);
      final fyGround = y(obs.elevationM);
      final fyRay = y(obs.sightRayElevationM);

      // Deficit penetration vertical line
      final penPaint = Paint()
        ..color = const Color(0xFFEF4444)
        ..strokeWidth = 2.0;
      canvas.drawLine(Offset(fx, fyGround), Offset(fx, fyRay), penPaint);

      // Obstacle Top Triangle
      final markerPaint = Paint()
        ..style = PaintingStyle.fill
        ..color = const Color(0xFFEF4444);
      canvas.drawPath(
        Path()
          ..moveTo(fx - 5, fyGround + 7)
          ..lineTo(fx, fyGround - 6)
          ..lineTo(fx + 5, fyGround + 7)
          ..close(),
        markerPaint,
      );
    }

    // 6. Observer & Target Optic Endpoints
    void drawEndpoint(double dx, double dyGround, double dyRay, Color color, String label, double groundElev) {
      // Mast / Optic height line
      canvas.drawLine(
        Offset(dx, dyGround),
        Offset(dx, dyRay),
        Paint()..color = color..strokeWidth = 2.0,
      );
      // Top Optic Circle
      canvas.drawCircle(Offset(dx, dyRay), 4.0, Paint()..color = color);
      canvas.drawCircle(Offset(dx, dyRay), 1.5, Paint()..color = const Color(0xFF0F172A));

      // Label
      final tp = TextPainter(
        text: TextSpan(
          text: '$label\n${groundElev.round()}م',
          style: TextStyle(color: color, fontSize: 9.0, fontWeight: FontWeight.bold),
        ),
        textAlign: TextAlign.center,
        textDirection: TextDirection.rtl,
      )..layout();
      tp.paint(canvas, Offset(dx - tp.width / 2, dyGround + 4));
    }

    drawEndpoint(x(0), y(samples.first.groundElevationM), y(samples.first.rayHeightM), const Color(0xFF38BDF8), 'الراصد', samples.first.groundElevationM);
    drawEndpoint(x(samples.length - 1), y(samples.last.groundElevationM), y(samples.last.rayHeightM), const Color(0xFFF59E0B), 'الهدف', samples.last.groundElevationM);

    // 7. Interactive Scrubber Cursor
    if (selectedIndex != null && selectedIndex! < samples.length) {
      final cur = samples[selectedIndex!];
      final sx = x(selectedIndex!);
      final syGround = y(cur.groundElevationM);
      final syRay = y(cur.rayHeightM);

      final curPaint = Paint()..color = Colors.white..strokeWidth = 1.2;
      canvas.drawLine(Offset(sx, pad), Offset(sx, h - pad), curPaint);
      canvas.drawCircle(Offset(sx, syGround), 3.5, Paint()..color = const Color(0xFF38BDF8));
      canvas.drawCircle(Offset(sx, syRay), 3.5, Paint()..color = const Color(0xFFF59E0B));
    }
  }

  @override
  bool shouldRepaint(covariant _LosProfilePainter oldDelegate) =>
      oldDelegate.report != report ||
      oldDelegate.clear != clear ||
      oldDelegate.selectedIndex != selectedIndex;
}