import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

import '../dji_service.dart';
import '../flight_model.dart';
import '../theme.dart';
import 'camera_settings_page.dart';
import 'capture_modes_page.dart';
import 'dji_video_view.dart';
import 'map_page.dart';
import 'pv_icons.dart';
import 'settings_menu_page.dart';

/// Landscape live-flight overlay — mirrors the v2 "Main flight view" mockup.
/// Live camera feed behind a glass HUD; real telemetry bound throughout, and
/// the shutter / mode switch / gimbal slider / RTH / take-off controls issue
/// real SDK commands via [DjiService].
class FlightControlPage extends StatefulWidget {
  const FlightControlPage({super.key, required this.model, required this.dji});

  final FlightModel model;
  final DjiService dji;

  @override
  State<FlightControlPage> createState() => _FlightControlPageState();
}

class _FlightControlPageState extends State<FlightControlPage> {
  Timer? _recTimer;
  int _recSeconds = 0;
  // Gimbal pitch slider: fraction 0 (top, +30°) … 1 (bottom, −90°).
  double _gimbalFrac = 0.24;
  bool _grid = false;

  DjiService get _dji => widget.dji;
  FlightModel get _m => widget.model;

  @override
  void initState() {
    super.initState();
    SystemChrome.setPreferredOrientations(<DeviceOrientation>[
      DeviceOrientation.landscapeLeft,
      DeviceOrientation.landscapeRight,
    ]);
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersiveSticky);
  }

  @override
  void dispose() {
    _recTimer?.cancel();
    SystemChrome.setPreferredOrientations(<DeviceOrientation>[DeviceOrientation.portraitUp]);
    SystemChrome.setEnabledSystemUIMode(SystemUiMode.edgeToEdge);
    super.dispose();
  }

  String _fmt(int s) => '${(s ~/ 60).toString().padLeft(2, '0')}:${(s % 60).toString().padLeft(2, '0')}';

  void _snack(String msg) {
    if (!mounted) return;
    ScaffoldMessenger.of(context)
      ..clearSnackBars()
      ..showSnackBar(SnackBar(content: Text(msg)));
  }

  Future<void> _run(String label, Future<void> Function() action) async {
    try {
      await action();
    } catch (e) {
      _snack('$label failed: ${_reason(e)}');
    }
  }

  String _reason(Object e) => e is PlatformException ? (e.message ?? e.code) : e.toString();

  // ── Commands ───────────────────────────────────────────────────────────────
  Future<void> _toggleShutter() async {
    if (_m.captureMode == CaptureMode.video) {
      if (_m.isRecording) {
        _stopRecTimer();
        await _run('Stop recording', _dji.stopRecordVideo);
      } else {
        _startRecTimer();
        await _run('Start recording', _dji.startRecordVideo);
      }
    } else {
      await _run('Shoot photo', _dji.startShootPhoto);
    }
  }

  void _startRecTimer() {
    _recSeconds = 0;
    _recTimer?.cancel();
    _recTimer = Timer.periodic(const Duration(seconds: 1), (_) {
      if (mounted) setState(() => _recSeconds++);
    });
  }

  void _stopRecTimer() {
    _recTimer?.cancel();
    _recTimer = null;
  }

  Future<void> _setCaptureMode(CaptureMode mode) async {
    setState(() => _m.captureMode = mode);
    final String wire = mode == CaptureMode.video ? 'video' : 'photo';
    await _run('Set camera mode', () => _dji.setCameraMode(wire));
  }

  Future<void> _rth() async {
    final bool ok = await _confirm('Return to Home', 'The aircraft will fly back to its recorded home point and land.');
    if (ok) await _run('Return to Home', _dji.startGoHome);
  }

  Future<void> _toggleTakeoff() async {
    if (_m.isFlying == true) {
      final bool ok = await _confirm('Land now', 'The aircraft will descend and land at its current position.');
      if (ok) await _run('Land', _dji.land);
    } else {
      final bool ok = await _confirm('Take off', 'The aircraft will take off and hover at ~1.2 m.');
      if (ok) await _run('Take off', _dji.takeOff);
    }
  }

  Future<bool> _confirm(String title, String body) async {
    final bool? r = await showDialog<bool>(
      context: context,
      builder: (BuildContext ctx) => AlertDialog(
        backgroundColor: const Color(0xFF10203F),
        title: Text(title, style: const TextStyle(color: Glass.ink, fontFamily: PV.fontSans, fontWeight: FontWeight.w700)),
        content: Text(body, style: const TextStyle(color: Color(0xFF8FA0BE), fontFamily: PV.fontSans)),
        actions: <Widget>[
          TextButton(onPressed: () => Navigator.pop(ctx, false), child: const Text('Cancel')),
          FilledButton(onPressed: () => Navigator.pop(ctx, true), child: Text(title)),
        ],
      ),
    );
    return r ?? false;
  }

  void _onGimbalDrag(double frac) {
    setState(() => _gimbalFrac = frac.clamp(0.0, 1.0));
    final double pitch = 30 - _gimbalFrac * 120; // +30 (top) … −90 (bottom)
    _run('Gimbal', () => _dji.rotateGimbalPitch(pitch));
  }

  void _openCaptureModes() {
    Navigator.of(context).push(MaterialPageRoute<void>(
      builder: (_) => CaptureModesPage(model: _m, dji: _dji),
    ));
  }

  void _openCameraSettings() {
    Navigator.of(context).push(MaterialPageRoute<void>(
      builder: (_) => CameraSettingsPage(model: _m, dji: _dji),
    ));
  }

  void _openSettingsMenu() {
    Navigator.of(context).push(MaterialPageRoute<void>(
      builder: (_) => SettingsMenuPage(model: _m, dji: _dji),
    ));
  }

  void _openMap() {
    Navigator.of(context).push(MaterialPageRoute<void>(
      builder: (_) => MapPage(model: _m, dji: _dji),
    ));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: const Color(0xFF0A1120),
      body: AnimatedBuilder(
        animation: _m,
        builder: (BuildContext context, _) {
          return Stack(
            children: <Widget>[
              Positioned.fill(
                child: _m.connected
                    ? const DjiVideoView()
                    : const CustomPaint(painter: _FeedPainter()),
              ),
              if (_grid) const Positioned.fill(child: IgnorePointer(child: CustomPaint(painter: _GridPainter()))),
              const Center(child: PVIcon('crosshair', size: 30, stroke: 1.1, color: Color(0xB3FFFFFF))),
              Positioned(top: 12, left: 14, right: 14, child: _topBar()),
              Positioned(left: 14, top: 58, child: _leftRail()),
              Positioned(left: 70, top: 58, bottom: 96, child: _gimbalSlider()),
              Positioned(right: 16, top: 0, bottom: 0, child: Center(child: _cameraControls())),
              Positioned(left: 14, bottom: 12, child: _minimap()),
              Positioned(bottom: 14, left: 0, right: 0, child: Center(child: _telemetry())),
              Positioned(right: 92, bottom: 20, child: _rthButton()),
              Positioned(right: 92, bottom: 72, child: _takeoffButton()),
            ],
          );
        },
      ),
    );
  }

  // ── Top bar ──────────────────────────────────────────────────────────────
  Widget _topBar() {
    final String mode = (_m.flightMode != null && _m.flightMode!.isNotEmpty) ? _m.flightMode! : 'N';
    return Row(children: <Widget>[
      GestureDetector(
        onTap: () => Navigator.of(context).maybePop(),
        child: _pill(child: const PVIcon('chevronLeft', size: 16, color: Glass.ink)),
      ),
      const SizedBox(width: 8),
      Container(
        height: 26,
        padding: const EdgeInsets.symmetric(horizontal: 11),
        decoration: BoxDecoration(color: Glass.accent, borderRadius: BorderRadius.circular(8)),
        alignment: Alignment.center,
        child: Text(mode, style: const TextStyle(fontFamily: PV.fontSans, fontSize: 12, fontWeight: FontWeight.w700, letterSpacing: 0.4, color: Colors.white)),
      ),
      const SizedBox(width: 8),
      _pill(child: Row(mainAxisSize: MainAxisSize.min, children: <Widget>[
        const PVIcon('satellite', size: 14, color: Glass.sat),
        const SizedBox(width: 4),
        _mono(_m.satellites?.toString() ?? '0'),
      ])),
      const SizedBox(width: 8),
      _pill(child: const PVIcon('obstacle', size: 13, color: Glass.sat)),
      const SizedBox(width: 8),
      _pill(child: Row(mainAxisSize: MainAxisSize.min, children: <Widget>[
        const PVIcon('radio', size: 14, color: Glass.ink),
        const SizedBox(width: 4),
        _mono('HD'),
      ])),
      const Spacer(),
      _pill(child: Row(mainAxisSize: MainAxisSize.min, children: <Widget>[
        _mono('REC'),
        const SizedBox(width: 6),
        Container(width: 7, height: 7, decoration: BoxDecoration(color: _m.isRecording ? Glass.rec : const Color(0x66D64545), shape: BoxShape.circle)),
        const SizedBox(width: 6),
        _mono(_fmt(_m.isRecording ? _recSeconds : 0)),
      ])),
      const SizedBox(width: 8),
      _pill(child: Row(mainAxisSize: MainAxisSize.min, children: <Widget>[
        const PVIcon('battery', size: 16, color: Glass.sat),
        const SizedBox(width: 4),
        _mono(_m.batteryPercent == null ? '—' : '${_m.batteryPercent}%'),
      ])),
      const SizedBox(width: 8),
      GestureDetector(onTap: _openSettingsMenu, child: _pill(child: const PVIcon('more', size: 16, color: Glass.ink))),
    ]);
  }

  Widget _leftRail() {
    return Column(children: <Widget>[
      _sideBtn('gimbal', active: true, onTap: _openCameraSettings),
      const SizedBox(height: 10),
      _sideBtn('sun', onTap: _openCameraSettings),
      const SizedBox(height: 10),
      _sideBtn('aperture', onTap: _openCaptureModes),
      const SizedBox(height: 10),
      _sideBtn('grid', active: _grid, onTap: () => setState(() => _grid = !_grid)),
    ]);
  }

  // ── Reusable glass pieces ────────────────────────────────────────────────
  Widget _pill({required Widget child}) {
    return Container(
      height: 26,
      padding: const EdgeInsets.symmetric(horizontal: 10),
      decoration: BoxDecoration(color: Glass.pill, borderRadius: BorderRadius.circular(8)),
      alignment: Alignment.center,
      child: child,
    );
  }

  Widget _mono(String t) => Text(t, style: const TextStyle(fontFamily: PV.fontMono, fontSize: 12, color: Glass.ink));

  Widget _sideBtn(String icon, {bool active = false, VoidCallback? onTap}) {
    return GestureDetector(
      onTap: onTap,
      child: Container(
        width: 42, height: 42,
        decoration: BoxDecoration(
          color: active ? Glass.accent : Glass.pill,
          borderRadius: BorderRadius.circular(12),
          border: Border.all(color: Glass.hairline),
        ),
        alignment: Alignment.center,
        child: PVIcon(icon, size: 20, stroke: 1.8, color: Glass.ink),
      ),
    );
  }

  Widget _gimbalSlider() {
    return LayoutBuilder(builder: (BuildContext context, BoxConstraints c) {
      final double h = c.maxHeight;
      return GestureDetector(
        behavior: HitTestBehavior.opaque,
        onVerticalDragUpdate: (DragUpdateDetails d) => _onGimbalDrag(d.localPosition.dy / h),
        onTapDown: (TapDownDetails d) => _onGimbalDrag(d.localPosition.dy / h),
        child: SizedBox(
          width: 16,
          child: Stack(children: <Widget>[
            Align(
              alignment: Alignment.topCenter,
              child: Container(width: 6, height: h, decoration: BoxDecoration(color: Glass.pill, borderRadius: BorderRadius.circular(6))),
            ),
            Positioned(
              top: (_gimbalFrac * h - 8).clamp(0.0, h - 16),
              left: 0,
              child: const _Thumb(),
            ),
          ]),
        ),
      );
    });
  }

  Widget _cameraControls() {
    return Column(mainAxisSize: MainAxisSize.min, children: <Widget>[
      GestureDetector(
        onTap: _openCameraSettings,
        child: Container(
          width: 46, height: 46,
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(10),
            border: Border.all(color: const Color(0x99FFFFFF), width: 2),
            gradient: const LinearGradient(begin: Alignment.topLeft, end: Alignment.bottomRight, colors: <Color>[Color(0xFF2A4E86), Color(0xFF12201A)]),
          ),
        ),
      ),
      const SizedBox(height: 14),
      GestureDetector(
        onTap: _toggleShutter,
        child: Container(
          width: 62, height: 62,
          decoration: BoxDecoration(shape: BoxShape.circle, border: Border.all(color: const Color(0xD9FFFFFF), width: 4)),
          child: Center(
            child: _m.captureMode == CaptureMode.video && _m.isRecording
                ? Container(width: 24, height: 24, decoration: BoxDecoration(color: Glass.rec, borderRadius: BorderRadius.circular(5)))
                : Container(width: 46, height: 46, decoration: BoxDecoration(color: _m.captureMode == CaptureMode.video ? Glass.rec : Colors.white, shape: BoxShape.circle)),
          ),
        ),
      ),
      const SizedBox(height: 14),
      Container(
        padding: const EdgeInsets.all(3),
        decoration: BoxDecoration(color: Glass.pill, borderRadius: BorderRadius.circular(10)),
        child: Column(children: <Widget>[
          _modeBtn('image', CaptureMode.photo),
          _modeBtn('video', CaptureMode.video),
          _modeBtn('film', CaptureMode.pano),
        ]),
      ),
    ]);
  }

  Widget _modeBtn(String icon, CaptureMode mode) {
    final bool active = _m.captureMode == mode;
    return GestureDetector(
      onTap: () => _setCaptureMode(mode),
      child: Container(
        width: 40, height: 30,
        margin: const EdgeInsets.symmetric(vertical: 1),
        decoration: BoxDecoration(color: active ? Glass.accent : Colors.transparent, borderRadius: BorderRadius.circular(7)),
        alignment: Alignment.center,
        child: PVIcon(icon, size: 17, stroke: 1.8, color: Glass.ink),
      ),
    );
  }

  Widget _minimap() {
    final String rth = _m.homeDistance == null ? 'RTH —' : 'RTH ${_m.homeDistance!.toStringAsFixed(0)}m';
    return GestureDetector(
      onTap: _openMap,
      child: Container(
        width: 148, height: 78,
        decoration: BoxDecoration(color: Glass.pillStrong, borderRadius: BorderRadius.circular(12), border: Border.all(color: Glass.hairline)),
        child: Stack(children: <Widget>[
          const Positioned.fill(child: CustomPaint(painter: _MinimapPainter())),
          Positioned(top: 6, left: 8, child: Row(children: <Widget>[
            const PVIcon('home', size: 12, color: Glass.ink),
            const SizedBox(width: 5),
            Text(rth, style: const TextStyle(fontFamily: PV.fontMono, fontSize: 10, color: Glass.ink)),
          ])),
        ]),
      ),
    );
  }

  Widget _telemetry() {
    String f(double? v, {int d = 1}) => v == null ? '—' : v.toStringAsFixed(d);
    final List<(String, String, String)> fields = <(String, String, String)>[
      ('H', f(_m.altitude), 'm'),
      ('D', f(_m.homeDistance, d: 0), 'm'),
      ('H.S', f(_m.horizontalSpeed), 'm/s'),
      ('V.S', f(_m.verticalSpeed), 'm/s'),
    ];
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 18, vertical: 8),
      decoration: BoxDecoration(color: Glass.pill, borderRadius: BorderRadius.circular(12)),
      child: Row(mainAxisSize: MainAxisSize.min, children: <Widget>[
        for (int i = 0; i < fields.length; i++) ...<Widget>[
          if (i > 0) const SizedBox(width: 20),
          Column(mainAxisSize: MainAxisSize.min, children: <Widget>[
            Text(fields[i].$1, style: const TextStyle(fontFamily: PV.fontMono, fontSize: 10, letterSpacing: 0.8, color: Color(0x99EAF0FA))),
            const SizedBox(height: 2),
            Text.rich(TextSpan(children: <TextSpan>[
              TextSpan(text: fields[i].$2, style: const TextStyle(fontFamily: PV.fontMono, fontSize: 15, fontWeight: FontWeight.w700, color: Glass.ink)),
              TextSpan(text: ' ${fields[i].$3}', style: const TextStyle(fontFamily: PV.fontMono, fontSize: 10, color: Color(0x99EAF0FA))),
            ])),
          ]),
        ],
      ]),
    );
  }

  Widget _rthButton() {
    return GestureDetector(
      onTap: _rth,
      child: Container(
        width: 44, height: 44,
        decoration: BoxDecoration(color: Glass.pillStrong, shape: BoxShape.circle, border: Border.all(color: const Color(0x2EFFFFFF))),
        alignment: Alignment.center,
        child: const PVIcon('rth', size: 20, color: Glass.ink),
      ),
    );
  }

  Widget _takeoffButton() {
    final bool flying = _m.isFlying == true;
    return GestureDetector(
      onTap: _toggleTakeoff,
      child: Container(
        width: 44, height: 44,
        decoration: BoxDecoration(color: flying ? const Color(0xE6D64545) : Glass.accent, shape: BoxShape.circle, border: Border.all(color: const Color(0x2EFFFFFF))),
        alignment: Alignment.center,
        child: PVIcon(flying ? 'home' : 'takeoff', size: 20, color: Colors.white),
      ),
    );
  }
}

class _Thumb extends StatelessWidget {
  const _Thumb();
  @override
  Widget build(BuildContext context) {
    return Container(
      width: 16, height: 16,
      decoration: const BoxDecoration(
        color: Glass.ink, shape: BoxShape.circle,
        boxShadow: <BoxShadow>[BoxShadow(color: Color(0x80000000), blurRadius: 3, offset: Offset(0, 1))],
      ),
    );
  }
}

/// Rule-of-thirds grid overlay toggled from the left rail.
class _GridPainter extends CustomPainter {
  const _GridPainter();
  @override
  void paint(Canvas canvas, Size size) {
    final Paint p = Paint()
      ..color = const Color(0x33FFFFFF)
      ..strokeWidth = 1;
    for (int i = 1; i < 3; i++) {
      final double x = size.width * i / 3, y = size.height * i / 3;
      canvas.drawLine(Offset(x, 0), Offset(x, size.height), p);
      canvas.drawLine(Offset(0, y), Offset(size.width, y), p);
    }
  }

  @override
  bool shouldRepaint(covariant _GridPainter oldDelegate) => false;
}

/// Painted placeholder camera feed: graded sky→ground, perspective grid, haze,
/// distant buildings, and a yellow tracked-subject bracket.
class _FeedPainter extends CustomPainter {
  const _FeedPainter();

  @override
  void paint(Canvas canvas, Size size) {
    final double w = size.width, h = size.height;
    final double horizon = h * 0.52;

    final Rect full = Offset.zero & size;
    final Paint sky = Paint()
      ..shader = const LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: <Color>[Color(0xFF2A4E86), Color(0xFF3E6199), Color(0xFF1C2A1E), Color(0xFF0E1710)],
        stops: <double>[0.0, 0.51, 0.54, 1.0],
      ).createShader(full);
    canvas.drawRect(full, sky);

    final Paint haze = Paint()
      ..shader = LinearGradient(
        begin: Alignment.topCenter,
        end: Alignment.bottomCenter,
        colors: <Color>[const Color(0x808FB4D8), const Color(0x008FB4D8)],
      ).createShader(Rect.fromLTWH(0, horizon - 30, w, 60));
    canvas.drawRect(Rect.fromLTWH(0, horizon - 30, w, 60), haze);

    final Paint bld = Paint()..color = const Color(0xE612201A);
    void building(double x, double y, double bw, double bh) => canvas.drawRect(Rect.fromLTWH(x * w, horizon + y, bw, bh), bld);
    building(0.10, -40, 46, 40);
    building(0.17, -52, 30, 52);
    building(0.74, -46, 54, 46);
    building(0.83, -34, 34, 34);

    final Paint grid = Paint()
      ..color = const Color(0x297FE0B0)
      ..strokeWidth = 1;
    for (int i = 1; i <= 5; i++) {
      final double t = i / 5.0;
      final double y = horizon + (h - horizon) * t * t;
      canvas.drawLine(Offset(0, y), Offset(w, y), grid);
    }
    final double vx = w / 2;
    for (int k = -6; k <= 6; k += 2) {
      final double bx = vx + k * (w * 0.16);
      canvas.drawLine(Offset(vx + k * 10, horizon), Offset(bx, h), grid);
    }

    final Paint subj = Paint()
      ..color = Glass.subject
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2;
    const double bxw = 118, bxh = 82;
    final Rect box = Rect.fromCenter(center: Offset(vx, horizon + 8), width: bxw, height: bxh);
    const double c = 14;
    canvas.drawPath(Path()..moveTo(box.left + c, box.top)..lineTo(box.left, box.top)..lineTo(box.left, box.top + c), subj);
    canvas.drawPath(Path()..moveTo(box.right - c, box.top)..lineTo(box.right, box.top)..lineTo(box.right, box.top + c), subj);
    canvas.drawPath(Path()..moveTo(box.left + c, box.bottom)..lineTo(box.left, box.bottom)..lineTo(box.left, box.bottom - c), subj);
    canvas.drawPath(Path()..moveTo(box.right - c, box.bottom)..lineTo(box.right, box.bottom)..lineTo(box.right, box.bottom - c), subj);
  }

  @override
  bool shouldRepaint(covariant _FeedPainter oldDelegate) => false;
}

class _MinimapPainter extends CustomPainter {
  const _MinimapPainter();

  @override
  void paint(Canvas canvas, Size size) {
    final Path route = Path()
      ..moveTo(20, 60)
      ..cubicTo(50, 40, 70, 30, 120, 24);
    final Paint line = Paint()
      ..color = const Color(0xFF5B93F5)
      ..style = PaintingStyle.stroke
      ..strokeWidth = 2;
    canvas.drawPath(route, line);
    canvas.drawCircle(const Offset(20, 60), 4, Paint()..color = Glass.sat);
    canvas.drawCircle(const Offset(120, 24), 4, Paint()..color = const Color(0xFF5B93F5));
  }

  @override
  bool shouldRepaint(covariant _MinimapPainter oldDelegate) => false;
}