import React from 'react';
import { clsx } from 'clsx';
import { twMerge } from 'tailwind-merge';

interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
  variant?: 'primary' | 'secondary' | 'outline' | 'ghost' | 'danger' | 'pastel';
  size?: 'sm' | 'md' | 'lg';
  isLoading?: boolean;
}

export const Button: React.FC<ButtonProps> = ({
  children,
  className,
  variant = 'primary',
  size = 'md',
  isLoading = false,
  disabled,
  ...props
}) => {
  const baseStyles =
    'inline-flex items-center justify-center font-semibold rounded-xl transition-all duration-150 active:scale-[0.98] disabled:opacity-50 disabled:pointer-events-none focus:outline-none focus:ring-2 focus:ring-offset-2';

  const sizeStyles = {
    sm: 'px-3 py-1.5 text-xs gap-1.5',
    md: 'px-4 py-2 text-sm gap-2',
    lg: 'px-6 py-2.5 text-base gap-2.5',
  };

  const variantStyles = {
    primary:
      'bg-brand-primary text-white hover:bg-brand-hover shadow-sm hover:shadow-brand-glow focus:ring-brand-primary',
    secondary:
      'bg-brand-secondary text-white hover:bg-brand-hover focus:ring-brand-secondary',
    pastel:
      'bg-brand-pastel/30 text-brand-dark hover:bg-brand-pastel/60 border border-brand-pastel focus:ring-brand-pastel',
    outline:
      'border border-slate-200 bg-white text-slate-700 hover:bg-slate-50 hover:border-slate-300 focus:ring-slate-300',
    ghost:
      'bg-transparent text-slate-600 hover:bg-slate-100 hover:text-slate-900 focus:ring-slate-200',
    danger:
      'bg-red-600 text-white hover:bg-red-700 shadow-sm focus:ring-red-500',
  };

  return (
    <button
      className={twMerge(
        clsx(
          baseStyles,
          sizeStyles[size],
          variantStyles[variant],
          className
        )
      )}
      disabled={disabled || isLoading}
      {...props}
    >
      {isLoading && (
        <svg
          className="animate-spin -ml-1 mr-2 h-4 w-4 text-current"
          fill="none"
          viewBox="0 0 24 24"
        >
          <circle
            className="opacity-25"
            cx="12"
            cy="12"
            r="10"
            stroke="currentColor"
            strokeWidth="4"
          />
          <path
            className="opacity-75"
            fill="currentColor"
            d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
          />
        </svg>
      )}
      {children}
    </button>
  );
};