import * as React from "react"
import { cva, type VariantProps } from "class-variance-authority"
import { cn } from "cn"
import { Slot } from "radix-ui"
import { Loader2 } from "lucide-react"

const buttonVariants = cva(
  "group/button inline-flex shrink-0 items-center justify-center rounded-lg border border-transparent bg-clip-padding text-sm font-medium whitespace-nowrap transition-all outline-none select-none focus-visible:border-ring focus-visible:ring-3 focus-visible:ring-ring/50 active:not-aria-[haspopup]:translate-y-px disabled:pointer-events-none disabled:opacity-50 aria-invalid:border-destructive aria-invalid:ring-3 aria-invalid:ring-destructive/20 dark:aria-invalid:border-destructive/50 dark:aria-invalid:ring-destructive/40 [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4",
  {
    variants: {
      variant: {
        // Primary structural button: Black (#020202) background with near-white (#FEFEFE) text
        default: "bg-primary text-primary-foreground hover:bg-[#1F1C1A] dark:hover:bg-[#D6D6D6] active:scale-[0.98]",
        // Brand CTA variant: Black with white text, high contrast and subtle elevation
        brand:
          "relative overflow-hidden bg-primary text-primary-foreground shadow-sm transition-[transform,background-color] hover:bg-[#1F1C1A] dark:hover:bg-[#D6D6D6] active:scale-[0.98] motion-reduce:transition-none motion-reduce:active:scale-100 font-semibold",
        // Accent CTA variant: vibrant brand gradient with glow and crisp white text
        accent:
          "relative overflow-hidden bg-gradient-brand text-white shadow-md glow-brand transition-all hover:brightness-105 active:scale-[0.98] motion-reduce:transition-none motion-reduce:active:scale-100 font-bold [&_svg]:text-white",
        outline:
          "border-border bg-background text-foreground hover:bg-muted hover:text-foreground aria-expanded:bg-muted aria-expanded:text-foreground dark:border-border dark:bg-card dark:hover:bg-secondary",
        secondary:
          "bg-secondary text-secondary-foreground hover:bg-[#D6D6D6]/40 dark:hover:bg-[#343332] aria-expanded:bg-secondary aria-expanded:text-secondary-foreground",
        ghost:
          "hover:bg-muted hover:text-foreground aria-expanded:bg-muted aria-expanded:text-foreground dark:hover:bg-muted/50",
        destructive:
          "bg-destructive text-destructive-foreground hover:bg-destructive/90 focus-visible:border-destructive/40 focus-visible:ring-destructive/20 active:scale-[0.98] shadow-xs font-semibold",
        "destructive-subtle":
          "bg-destructive/10 text-destructive hover:bg-destructive/20 focus-visible:border-destructive/40 focus-visible:ring-destructive/20 dark:bg-destructive/20 dark:hover:bg-destructive/30 dark:focus-visible:ring-destructive/40",
        link: "text-primary underline-offset-4 hover:underline",
      },
      size: {
        default:
          "h-8 gap-1.5 px-2.5 has-data-[icon=inline-end]:pr-2 has-data-[icon=inline-start]:pl-2",
        xs: "h-6 gap-1 rounded-[min(var(--radius-md),10px)] px-2 text-xs in-data-[slot=button-group]:rounded-lg has-data-[icon=inline-end]:pr-1.5 has-data-[icon=inline-start]:pl-1.5 [&_svg:not([class*='size-'])]:size-3",
        sm: "h-7 gap-1 rounded-[min(var(--radius-md),12px)] px-2.5 text-[0.8rem] in-data-[slot=button-group]:rounded-lg has-data-[icon=inline-end]:pr-1.5 has-data-[icon=inline-start]:pl-1.5 [&_svg:not([class*='size-'])]:size-3.5",
        lg: "h-9 gap-1.5 px-2.5 has-data-[icon=inline-end]:pr-2 has-data-[icon=inline-start]:pl-2",
        // Marketing sizes (§5.4/§6.3) — larger, rounded-full pills for CTAs
        md: "h-10 gap-2 px-4 has-data-[icon=inline-end]:pr-3 has-data-[icon=inline-start]:pl-3 [&_svg:not([class*='size-'])]:size-4",
        "pill-sm": "h-9 gap-1.5 rounded-full px-4 [&_svg:not([class*='size-'])]:size-4",
        pill: "h-11 gap-2 rounded-full px-6 text-[0.9375rem] [&_svg:not([class*='size-'])]:size-4.5",
        "pill-lg":
          "h-12 gap-2 rounded-full px-7 text-base [&_svg:not([class*='size-'])]:size-5",
        icon: "size-8",
        "icon-xs":
          "size-6 rounded-[min(var(--radius-md),10px)] in-data-[slot=button-group]:rounded-lg [&_svg:not([class*='size-'])]:size-3",
        "icon-sm":
          "size-7 rounded-[min(var(--radius-md),12px)] in-data-[slot=button-group]:rounded-lg",
        "icon-lg": "size-9",
      },
    },
    defaultVariants: {
      variant: "default",
      size: "default",
    },
  }
)

function Button({
  className,
  variant = "default",
  size = "default",
  asChild = false,
  loading = false,
  disabled,
  children,
  ...props
}: React.ComponentProps<"button"> &
  VariantProps<typeof buttonVariants> & {
    asChild?: boolean
    loading?: boolean
  }) {
  const Comp = asChild ? Slot.Root : "button"

  // asChild forwards to a single child (e.g. a Link); don't inject a spinner there.
  const content =
    loading && !asChild ? (
      <>
        <Loader2 className="animate-spin motion-reduce:animate-none" aria-hidden />
        {children}
      </>
    ) : (
      children
    )

  return (
    <Comp
      data-slot="button"
      data-variant={variant}
      data-size={size}
      aria-busy={loading || undefined}
      disabled={asChild ? undefined : disabled || loading}
      className={cn(buttonVariants({ variant, size, className }))}
      {...props}
    >
      {content}
    </Comp>
  )
}

export { Button, buttonVariants }