import 'package:flutter/material.dart';

/// Toggle button representing the current user's registration state for an
/// event. Local-state only for now — a future revision will wire this to
/// Firestore via the events repository.
class RegistrationButton extends StatefulWidget {
  const RegistrationButton({
    super.key,
    this.initiallyRegistered = false,
    this.enabled = true,
    this.fullWidth = false,
    this.onChanged,
  });

  final bool initiallyRegistered;
  final bool enabled;
  final bool fullWidth;
  final ValueChanged<bool>? onChanged;

  @override
  State<RegistrationButton> createState() => _RegistrationButtonState();
}

class _RegistrationButtonState extends State<RegistrationButton> {
  late bool _registered;

  @override
  void initState() {
    super.initState();
    _registered = widget.initiallyRegistered;
  }

  void _toggle() {
    setState(() => _registered = !_registered);
    widget.onChanged?.call(_registered);
  }

  @override
  Widget build(BuildContext context) {
    final scheme = Theme.of(context).colorScheme;

    final child = _registered
        ? OutlinedButton.icon(
            onPressed: widget.enabled ? _toggle : null,
            icon: Icon(Icons.check_circle, color: scheme.primary),
            label: const Text('Registered'),
            style: OutlinedButton.styleFrom(
              foregroundColor: scheme.primary,
              side: BorderSide(color: scheme.primary),
              padding: const EdgeInsets.symmetric(
                horizontal: 20,
                vertical: 14,
              ),
            ),
          )
        : FilledButton.icon(
            onPressed: widget.enabled ? _toggle : null,
            icon: const Icon(Icons.how_to_reg),
            label: const Text('Register'),
            style: FilledButton.styleFrom(
              padding: const EdgeInsets.symmetric(
                horizontal: 20,
                vertical: 14,
              ),
            ),
          );

    if (widget.fullWidth) {
      return SizedBox(width: double.infinity, child: child);
    }
    return child;
  }
}