m8chat-app2/lib/features/panic/presentation/panic_button.dart

// Version: 1.1.0 | Created: 2026-07-04 | Updated: 2026-07-04
// Panic trigger button for the rooms AppBar. Push-to-talk style: HOLD for
// 700ms to fire the alert, with a filling ring showing progress so a brush
// cannot fire it and the user sees exactly when it sends. A plain tap only
// shows the hint. Only rendered when a panic configuration exists.

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

import '../data/panic_repository.dart';

class PanicButton extends ConsumerStatefulWidget {
  const PanicButton({super.key});

  @override
  ConsumerState<PanicButton> createState() => _PanicButtonState();
}

class _PanicButtonState extends ConsumerState<PanicButton>
    with SingleTickerProviderStateMixin {
  static const _holdDuration = Duration(milliseconds: 700);

  late final AnimationController _holdController;
  bool _sending = false;

  @override
  void initState() {
    super.initState();
    _holdController = AnimationController(vsync: this, duration: _holdDuration)
      ..addStatusListener(_onHoldStatus);
  }

  @override
  void dispose() {
    _holdController.dispose();
    super.dispose();
  }

  void _onHoldStatus(AnimationStatus status) {
    // The ring filled all the way: the hold completed, fire the alert.
    if (status == AnimationStatus.completed) {
      HapticFeedback.heavyImpact();
      _trigger();
      _holdController.reset();
    }
  }

  void _onHoldStart() {
    if (_sending) return;
    _holdController.forward(from: 0);
  }

  void _onHoldCancelled() {
    // Released before the ring filled: cancel silently.
    if (_holdController.status == AnimationStatus.forward) {
      _holdController.reset();
    }
  }

  Future<void> _trigger() async {
    if (_sending) return;
    setState(() => _sending = true);
    final messenger = ScaffoldMessenger.of(context);
    messenger.showSnackBar(
      const SnackBar(content: Text('Sending emergency alert…')),
    );
    final error = await ref.read(panicRepositoryProvider).trigger();
    if (!mounted) return;
    setState(() => _sending = false);
    messenger.hideCurrentSnackBar();
    messenger.showSnackBar(
      SnackBar(
        backgroundColor: error == null ? Colors.green.shade800 : null,
        content: Text(error ?? 'Emergency alert sent with your location.'),
      ),
    );
  }

  void _showHint() {
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(
        content: Text('Hold the button to send the emergency alert.'),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    // Hide when not configured. Config lives in account data, which is
    // available once sync has run; rebuilds happen with the parent screen.
    final configured = ref.watch(panicRepositoryProvider).config != null;
    if (!configured) return const SizedBox.shrink();

    return GestureDetector(
      onTap: _showHint,
      onLongPressDown: (_) => _onHoldStart(),
      onLongPressUp: _onHoldCancelled,
      onLongPressCancel: _onHoldCancelled,
      child: Tooltip(
        message: 'Hold to send emergency alert',
        child: SizedBox(
          width: 48,
          height: 48,
          child: Center(
            child: SizedBox(
              width: 40,
              height: 40,
              child: Stack(
                alignment: Alignment.center,
                children: [
                  // Progress ring, only painted while the hold is in progress.
                  AnimatedBuilder(
                    animation: _holdController,
                    builder: (context, _) {
                      if (_holdController.value == 0) {
                        return const SizedBox.shrink();
                      }
                      return SizedBox(
                        width: 36,
                        height: 36,
                        child: CircularProgressIndicator(
                          value: _holdController.value,
                          strokeWidth: 3,
                          color: Colors.red,
                          backgroundColor: Colors.red.withAlpha(40),
                        ),
                      );
                    },
                  ),
                  if (_sending)
                    const SizedBox(
                      width: 20,
                      height: 20,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  else
                    const Icon(Icons.emergency_share, color: Colors.red),
                ],
              ),
            ),
          ),
        ),
      ),
    );
  }
}