import 'package:flutter/gestures.dart' show DragStartBehavior;
import 'package:flutter/material.dart';

import '../../../fly/virtual_sticks.dart';
import '../../../theme.dart';
import '../hud_kit.dart';

/// What each pad's axes do in [mode], for the captions under the pads.
({String left, String right}) stickCaptions(StickMode mode) => switch (mode) {
      StickMode.mode1 => (left: 'FWD · YAW', right: 'UP · SIDE'),
      StickMode.mode2 => (left: 'UP · YAW', right: 'FWD · SIDE'),
      StickMode.mode3 => (left: 'FWD · SIDE', right: 'UP · YAW'),
    };

/// One on-screen stick (plan P8): a ring the thumb drags a knob inside,
/// springing back to centre on release like a remote's stick. Reports −1…1
/// with y up; the drag starts where the finger lands, not after the slop.
class StickPad extends StatefulWidget {
  const StickPad({super.key, required this.value, required this.onChanged, required this.caption, this.size = 110});

  final Offset value;
  final ValueChanged<Offset> onChanged;
  final String caption;
  final double size;

  @override
  State<StickPad> createState() => _StickPadState();
}

class _StickPadState extends State<StickPad> {
  double get _radius => widget.size / 2 - 14;

  void _to(Offset local) {
    final Offset centre = Offset(widget.size / 2, widget.size / 2);
    widget.onChanged(StickMapper.normalise(local - centre, _radius));
  }

  @override
  Widget build(BuildContext context) {
    final Offset v = widget.value;
    final Offset knob = Offset(v.dx * _radius, -v.dy * _radius);
    final bool active = v != Offset.zero;
    return Column(mainAxisSize: MainAxisSize.min, children: <Widget>[
      GestureDetector(
        behavior: HitTestBehavior.opaque,
        dragStartBehavior: DragStartBehavior.down,
        onPanStart: (DragStartDetails d) => _to(d.localPosition),
        onPanUpdate: (DragUpdateDetails d) => _to(d.localPosition),
        onPanEnd: (_) => widget.onChanged(Offset.zero),
        onPanCancel: () => widget.onChanged(Offset.zero),
        child: SizedBox.square(
          dimension: widget.size,
          child: Stack(alignment: Alignment.center, children: <Widget>[
            Container(
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                color: Glass.pill,
                border: Border.all(color: active ? Glass.accent : const Color(0x4DEAF0FA), width: 1.5),
              ),
            ),
            // Cross-hair: the stick's two axes.
            Container(width: 1, height: widget.size - 28, color: Glass.hairline),
            Container(width: widget.size - 28, height: 1, color: Glass.hairline),
            Transform.translate(
              offset: knob,
              child: Container(
                width: 34,
                height: 34,
                decoration: BoxDecoration(
                  shape: BoxShape.circle,
                  color: active ? Glass.accent : const Color(0xCC253552),
                  border: Border.all(color: const Color(0x66FFFFFF)),
                ),
              ),
            ),
          ]),
        ),
      ),
      const SizedBox(height: 2),
      Text(widget.caption, style: HudText.label.copyWith(fontSize: 8)),
    ]);
  }
}

/// The rail's STICKS button: lit while the on-screen sticks fly the aircraft.
class SticksButton extends StatelessWidget {
  const SticksButton({super.key, required this.open, required this.onTap});

  final bool open;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return GlassPill(
      key: const ValueKey<String>('rail-sticks'),
      height: 24,
      color: open ? Glass.accent : Glass.pillStrong,
      padding: const EdgeInsets.symmetric(horizontal: 6),
      onTap: onTap,
      child: Text('STICKS', style: HudText.label.copyWith(fontSize: 8, color: Glass.ink, fontWeight: FontWeight.w700)),
    );
  }
}