import * as React from "react";
import { Slot } from "@radix-ui/react-slot";
import { cva, type VariantProps } from "class-variance-authority";
import { cn } from "@/lib/utils";
import { Spinner } from "@/components/ui/spinner";

const buttonVariants = cva(
  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium transition-colors disabled:pointer-events-none disabled:opacity-50",
  {
    variants: {
      variant: {
        default: "bg-black text-white hover:bg-zinc-800",
        outline:
          "border border-zinc-300 bg-white text-zinc-900 hover:bg-zinc-50",
        ghost: "text-zinc-700 hover:bg-zinc-100",
        destructive: "bg-red-600 text-white hover:bg-red-700",
        link: "text-zinc-900 underline-offset-4 hover:underline",
      },
      size: {
        default: "h-9 px-4 py-2",
        sm: "h-8 rounded-md px-3 text-xs",
        lg: "h-10 rounded-md px-6",
        icon: "h-9 w-9",
      },
    },
    defaultVariants: {
      variant: "default",
      size: "default",
    },
  },
);

export interface ButtonProps
  extends
    React.ButtonHTMLAttributes<HTMLButtonElement>,
    VariantProps<typeof buttonVariants> {
  asChild?: boolean;
  /** Shows a spinner; keeps the label. Never swap the label for loading text. */
  loading?: boolean;
}

const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
  (
    {
      className,
      variant,
      size,
      asChild = false,
      loading = false,
      disabled,
      children,
      ...props
    },
    ref,
  ) => {
    // Slot (asChild) requires exactly one element child — never inject spinner.
    if (asChild) {
      return (
        <Slot
          className={cn(buttonVariants({ variant, size, className }))}
          ref={ref}
          {...props}
        >
          {children}
        </Slot>
      );
    }

    return (
      <button
        className={cn(buttonVariants({ variant, size, className }))}
        ref={ref}
        disabled={disabled || loading}
        {...props}
      >
        {loading ? (
          <Spinner
            className={
              variant === "default" || variant === "destructive" || !variant
                ? "text-current"
                : undefined
            }
          />
        ) : null}
        {children}
      </button>
    );
  },
);
Button.displayName = "Button";

export { Button, buttonVariants };