import 'package:flutter/material.dart';

import '../services/auth_service.dart';
import '../theme/app_theme.dart';

class GoogleSignInButton extends StatefulWidget {
  const GoogleSignInButton({
    super.key,
    this.label = 'Continue with Google',
    this.compact = false,
    this.onSignedIn,
    this.onError,
  });

  final String label;
  final bool compact;
  final VoidCallback? onSignedIn;
  final void Function(Object error)? onError;

  @override
  State<GoogleSignInButton> createState() => _GoogleSignInButtonState();
}

class _GoogleSignInButtonState extends State<GoogleSignInButton> {
  bool _isLoading = false;

  Future<void> _signIn() async {
    setState(() => _isLoading = true);
    try {
      await AuthService.instance.signInWithGoogle();
      widget.onSignedIn?.call();
    } catch (error) {
      widget.onError?.call(error);
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final double verticalPadding = widget.compact ? 14 : 16;

    return SizedBox(
      width: double.infinity,
      child: FilledButton(
        onPressed: _isLoading ? null : _signIn,
        style: FilledButton.styleFrom(
          backgroundColor: Colors.white,
          foregroundColor: const Color(0xFF1F2937),
          disabledBackgroundColor: Colors.white.withValues(alpha: 0.7),
          padding: EdgeInsets.symmetric(vertical: verticalPadding),
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(12),
          ),
          elevation: 0,
        ),
        child: _isLoading
            ? const SizedBox(
                width: 22,
                height: 22,
                child: CircularProgressIndicator(
                  strokeWidth: 2.5,
                  color: AppColors.background,
                ),
              )
            : Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  const _GoogleLogo(size: 22),
                  const SizedBox(width: 12),
                  Flexible(
                    child: Text(
                      widget.label,
                      style: const TextStyle(
                        fontSize: 16,
                        fontWeight: FontWeight.w600,
                        color: Color(0xFF1F2937),
                      ),
                      textAlign: TextAlign.center,
                      overflow: TextOverflow.ellipsis,
                      maxLines: 1,
                    ),
                  ),
                ],
              ),
      ),
    );
  }
}

class _GoogleLogo extends StatelessWidget {
  const _GoogleLogo({required this.size});

  final double size;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      width: size,
      height: size,
      child: CustomPaint(painter: _GoogleLogoPainter()),
    );
  }
}

class _GoogleLogoPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    final double w = size.width;
    final double h = size.height;
    final Offset center = Offset(w / 2, h / 2);
    final double r = w * 0.42;

    void arc(Color color, double start, double sweep) {
      final Paint paint = Paint()
        ..color = color
        ..style = PaintingStyle.stroke
        ..strokeWidth = w * 0.18
        ..strokeCap = StrokeCap.round;
      canvas.drawArc(
        Rect.fromCircle(center: center, radius: r),
        start,
        sweep,
        false,
        paint,
      );
    }

    arc(const Color(0xFF4285F4), -0.4, 1.6);
    arc(const Color(0xFFEA4335), 1.2, 1.3);
    arc(const Color(0xFFFBBC05), 2.5, 1.3);
    arc(const Color(0xFF34A853), 3.8, 1.3);
  }

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