import { Button as ButtonPrimitive } from "@base-ui/react/button"
import { cva, type VariantProps } from "class-variance-authority"

import { cn } from "@/lib/utils"

// Icon-only buttons get a 44 px hit area under a coarse pointer, centred and invisible, so they
// stay small on screen but are easy to hit with a thumb or a glove (spec 4.5).
const HIT_AREA =
  "relative pointer-coarse:after:absolute pointer-coarse:after:top-1/2 pointer-coarse:after:left-1/2 pointer-coarse:after:size-11 pointer-coarse:after:-translate-1/2"

const buttonVariants = cva(
  "group/button inline-flex shrink-0 items-center justify-center rounded-xl border border-transparent bg-clip-padding text-sm font-medium whitespace-nowrap transition-all select-none motion-full:active:not-aria-[haspopup]:translate-y-px disabled:pointer-events-none disabled:opacity-50 aria-invalid:border-destructive aria-invalid:ring-1 aria-invalid:ring-inset aria-invalid:ring-destructive [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4",
  {
    variants: {
      variant: {
        default:
          "bg-primary text-primary-foreground shadow-[var(--shadow-soft)] hover:shadow-[var(--shadow-elevated)] hover:brightness-105 active:brightness-95",
        outline:
          "border-border bg-background hover:bg-muted hover:text-foreground aria-expanded:bg-muted aria-expanded:text-foreground",
        secondary:
          "bg-secondary text-secondary-foreground hover:bg-[color-mix(in_oklch,var(--secondary),var(--foreground)_5%)] aria-expanded:bg-secondary aria-expanded:text-secondary-foreground",
        ghost:
          "hover:bg-muted hover:text-foreground aria-expanded:bg-muted aria-expanded:text-foreground",
        destructive:
          "bg-destructive/10 text-destructive hover:bg-destructive/20",
        link: "text-primary-ink underline-offset-4 hover:underline",
      },
      size: {
        // 44 px for a thumb (often with gloves); compact only for a mouse or pen.
        default:
          "h-11 pointer-fine: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-9 pointer-fine: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",
        // 44 px: reliable with gloves or sticky fingers at the apiary.
        touch: "h-11 gap-2 px-4 text-base [&_svg:not([class*='size-'])]:size-5",
        icon: `size-8 ${HIT_AREA}`,
        "icon-xs":
          `size-6 rounded-[min(var(--radius-md),10px)] in-data-[slot=button-group]:rounded-lg [&_svg:not([class*='size-'])]:size-3 ${HIT_AREA}`,
        "icon-sm":
          `size-7 rounded-[min(var(--radius-md),12px)] in-data-[slot=button-group]:rounded-lg ${HIT_AREA}`,
        "icon-lg": `size-9 ${HIT_AREA}`,
      },
    },
    defaultVariants: {
      variant: "default",
      size: "default",
    },
  }
)

interface ButtonProps extends ButtonPrimitive.Props, VariantProps<typeof buttonVariants> {
  /**
   * A toolbar toggle (bold, italic, a list view): sets aria-pressed. Not for a choice between
   * options - that is a ChoiceGroup (spec 10.2).
   */
  pressed?: boolean
}

function Button({
  className,
  variant = "default",
  size = "default",
  pressed,
  ...props
}: ButtonProps) {
  return (
    <ButtonPrimitive
      data-slot="button"
      aria-pressed={pressed}
      className={cn(buttonVariants({ variant, size, className }))}
      {...props}
    />
  )
}

export { Button, buttonVariants }