import 'dart:math' as math;

import 'package:flutter/material.dart';

/// Radialmenue um den Reticle-Button im Editier-Modus (HTML-Demonstrator:
/// #haloSvg mit den drei Ring-Segmenten Loiter/Landing/Remove).
enum HaloAction { loiter, landing, remove }

class HaloMenu extends StatelessWidget {
  const HaloMenu({
    super.key,
    required this.loiterActive,
    required this.landingActive,
    required this.onAction,
  });

  final bool loiterActive;
  final bool landingActive;
  final void Function(HaloAction action) onAction;

  // Radien/Groesse 1:1 aus dem Demonstrator uebernommen
  // (HALO_SCALE=1.2, HALO_RIN=27, HALO_ROUT=60, viewBox 192x192).
  static const _size = 192.0;
  static const _innerRadius = 27 * 1.2;
  static const _outerRadius = 60 * 1.2;
  static const _midRadius = (_innerRadius + _outerRadius) / 2;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: _size,
      height: _size,
      child: Stack(
        alignment: Alignment.center,
        children: [
          _wedge(
            key: const ValueKey('halo-loiter'),
            startAngleDeg: -60,
            endAngleDeg: 60,
            active: loiterActive,
            onTap: () => onAction(HaloAction.loiter),
          ),
          _wedge(
            key: const ValueKey('halo-landing'),
            startAngleDeg: 60,
            endAngleDeg: 180,
            active: landingActive,
            onTap: () => onAction(HaloAction.landing),
          ),
          _wedge(
            key: const ValueKey('halo-remove'),
            startAngleDeg: 180,
            endAngleDeg: 300,
            active: false,
            onTap: () => onAction(HaloAction.remove),
          ),
          _wedgeIcon(angleDeg: 0, icon: Icons.loop),
          _wedgeIcon(angleDeg: 120, icon: Icons.flight_land),
          _wedgeIcon(angleDeg: 240, icon: Icons.remove),
        ],
      ),
    );
  }

  Widget _wedge({
    Key? key,
    required double startAngleDeg,
    required double endAngleDeg,
    required bool active,
    required VoidCallback onTap,
  }) {
    return ClipPath(
      key: key,
      clipper: _WedgeClipper(
        startAngleDeg: startAngleDeg,
        endAngleDeg: endAngleDeg,
        innerRadius: _innerRadius,
        outerRadius: _outerRadius,
      ),
      child: GestureDetector(
        onTap: onTap,
        child: Container(
          color: active
              ? const Color(0xFF4D9DFF).withValues(alpha: 0.55)
              : Colors.black.withValues(alpha: 0.62),
        ),
      ),
    );
  }

  Widget _wedgeIcon({required double angleDeg, required IconData icon}) {
    final point = _polarPoint(angleDeg, _midRadius);
    return Positioned(
      left: _size / 2 + point.dx - 12,
      top: _size / 2 + point.dy - 12,
      child: IgnorePointer(
        child: Icon(icon, color: Colors.white, size: 22),
      ),
    );
  }

  static Offset _polarPoint(double angleDeg, double radius) {
    final rad = angleDeg * math.pi / 180;
    return Offset(radius * math.sin(rad), -radius * math.cos(rad));
  }
}

class _WedgeClipper extends CustomClipper<Path> {
  const _WedgeClipper({
    required this.startAngleDeg,
    required this.endAngleDeg,
    required this.innerRadius,
    required this.outerRadius,
  });

  final double startAngleDeg;
  final double endAngleDeg;
  final double innerRadius;
  final double outerRadius;

  static const _steps = 18;

  @override
  Path getClip(Size size) {
    final center = Offset(size.width / 2, size.height / 2);

    Offset pointAt(double angleDeg, double radius) {
      final rad = angleDeg * math.pi / 180;
      return Offset(
        center.dx + radius * math.sin(rad),
        center.dy - radius * math.cos(rad),
      );
    }

    final path = Path();
    final first = pointAt(startAngleDeg, outerRadius);
    path.moveTo(first.dx, first.dy);
    for (var i = 1; i <= _steps; i++) {
      final a = startAngleDeg + (endAngleDeg - startAngleDeg) * i / _steps;
      final p = pointAt(a, outerRadius);
      path.lineTo(p.dx, p.dy);
    }
    for (var i = _steps; i >= 0; i--) {
      final a = startAngleDeg + (endAngleDeg - startAngleDeg) * i / _steps;
      final p = pointAt(a, innerRadius);
      path.lineTo(p.dx, p.dy);
    }
    path.close();
    return path;
  }

  @override
  bool shouldReclip(covariant _WedgeClipper oldClipper) =>
      oldClipper.startAngleDeg != startAngleDeg ||
      oldClipper.endAngleDeg != endAngleDeg ||
      oldClipper.innerRadius != innerRadius ||
      oldClipper.outerRadius != outerRadius;
}