import 'package:flutter/material.dart';

/// Custom authentication button with loading states and variants
class AuthButton extends StatelessWidget {
  final String text;
  final VoidCallback? onPressed;
  final bool isLoading;
  final AuthButtonVariant variant;
  final bool fullWidth;
  final Widget? icon;

  const AuthButton({
    super.key,
    required this.text,
    this.onPressed,
    this.isLoading = false,
    this.variant = AuthButtonVariant.primary,
    this.fullWidth = true,
    this.icon,
  });

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);
    final colors = _getColors(theme);

    return SizedBox(
      width: fullWidth ? double.infinity : null,
      height: 48,
      child: ElevatedButton(
        onPressed: isLoading ? null : onPressed,
        style: ElevatedButton.styleFrom(
          backgroundColor: colors.background,
          foregroundColor: colors.foreground,
          disabledBackgroundColor: colors.disabledBackground,
          disabledForegroundColor: colors.disabledForeground,
          elevation: variant == AuthButtonVariant.primary ? 2 : 0,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(8),
            side: variant == AuthButtonVariant.outline
                ? BorderSide(color: colors.background)
                : BorderSide.none,
          ),
        ),
        child: isLoading
            ? SizedBox(
                height: 20,
                width: 20,
                child: CircularProgressIndicator(
                  strokeWidth: 2,
                  valueColor: AlwaysStoppedAnimation<Color>(colors.foreground),
                ),
              )
            : Row(
                mainAxisSize: MainAxisSize.min,
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  if (icon != null) ...[
                    icon!,
                    const SizedBox(width: 8),
                  ],
                  Text(
                    text,
                    style: theme.textTheme.labelLarge?.copyWith(
                      fontWeight: FontWeight.w600,
                      color: colors.foreground,
                    ),
                  ),
                ],
              ),
      ),
    );
  }

  _ButtonColors _getColors(ThemeData theme) {
    switch (variant) {
      case AuthButtonVariant.primary:
        return _ButtonColors(
          background: theme.colorScheme.primary,
          foreground: theme.colorScheme.onPrimary,
          disabledBackground: theme.colorScheme.primary.withOpacity(0.12),
          disabledForeground: theme.colorScheme.onPrimary.withOpacity(0.38),
        );
      case AuthButtonVariant.secondary:
        return _ButtonColors(
          background: theme.colorScheme.secondary,
          foreground: theme.colorScheme.onSecondary,
          disabledBackground: theme.colorScheme.secondary.withOpacity(0.12),
          disabledForeground: theme.colorScheme.onSecondary.withOpacity(0.38),
        );
      case AuthButtonVariant.outline:
        return _ButtonColors(
          background: Colors.transparent,
          foreground: theme.colorScheme.primary,
          disabledBackground: Colors.transparent,
          disabledForeground: theme.colorScheme.primary.withOpacity(0.38),
        );
    }
  }
}

enum AuthButtonVariant {
  primary,
  secondary,
  outline,
}

class _ButtonColors {
  final Color background;
  final Color foreground;
  final Color disabledBackground;
  final Color disabledForeground;

  const _ButtonColors({
    required this.background,
    required this.foreground,
    required this.disabledBackground,
    required this.disabledForeground,
  });
}