import * as React from "react"
import { Slot } from "@radix-ui/react-slot"
import { cva, type VariantProps } from "class-variance-authority"

import { type as typeScale } from "@/lib/typography"
import { cn } from "@/lib/utils"

/**
 * Unified button system
 *
 * Variants (marketing hierarchy):
 * - default  → Primary (main CTA / conversion)
 * - secondary → Secondary (bordered supporting action)
 * - ghost    → Ghost (minimal / nav)
 *
 * Aliases kept for shadcn / existing blocks:
 * - outline → same as secondary
 *
 * Utility variants:
 * - destructive, link
 *
 * Surfaces:
 * - default → normal page canvas
 * - brand   → teal / dark marketing panels (inverse contrast)
 *
 * Sizes: sm | default (medium) | lg | icon-sm | icon | icon-lg
 *
 * Persian text: padding and height are sized for IRANSansX so glyphs
 * are not clipped; labels use `type.button` / `type["button-lg"]`.
 */
const buttonVariants = cva(
  [
    "inline-flex items-center justify-center whitespace-nowrap",
    "rounded-[var(--btn-radius)]",
    "transition-[color,background-color,border-color,box-shadow,opacity,transform]",
    "duration-200 ease-out",
    "outline-none select-none shrink-0",
    "disabled:pointer-events-none disabled:opacity-50 disabled:shadow-none",
    "[&_svg]:pointer-events-none [&_svg]:shrink-0",
    "[&_svg:not([class*='size-'])]:size-[var(--btn-icon-size)]",
    "focus-visible:ring-[3px] focus-visible:ring-ring/40 focus-visible:border-ring",
    "active:scale-[0.98]",
    "aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive",
  ].join(" "),
  {
    variants: {
      variant: {
        // Primary — brand neon rim via shadow-glow-*
        default:
          "bg-primary text-primary-foreground shadow-glow-sm hover:bg-primary-hover hover:shadow-glow-primary active:bg-primary-active",
        // Secondary (bordered) — preferred name
        secondary:
          "border border-surface bg-transparent text-foreground shadow-surface-sm hover:border-primary/45 hover:bg-accent hover:text-accent-foreground hover:shadow-glow-sm active:bg-accent/80 dark:border-white/18 dark:hover:border-primary/50 dark:hover:bg-accent",
        // Alias of secondary (shadcn / imported blocks)
        outline:
          "border border-surface bg-transparent text-foreground shadow-surface-sm hover:border-primary/45 hover:bg-accent hover:text-accent-foreground hover:shadow-glow-sm active:bg-accent/80 dark:border-white/18 dark:hover:border-primary/50 dark:hover:bg-accent",
        // Ghost
        ghost:
          "bg-transparent text-foreground hover:bg-accent hover:text-accent-foreground active:bg-accent/80 dark:hover:bg-white/8",
        destructive:
          "bg-destructive text-destructive-foreground shadow-sm hover:bg-destructive/90 hover:shadow-md focus-visible:ring-destructive/25 dark:focus-visible:ring-destructive/40 active:bg-destructive/85",
        link:
          "bg-transparent text-primary underline-offset-4 hover:underline hover:text-primary-hover active:text-primary-active",
      },
      surface: {
        default: "",
        /** Inverse contrast for brand / dark marketing panels */
        brand: "",
      },
      size: {
        sm: cn(
          "h-[var(--btn-height-sm)] gap-[var(--btn-gap-sm)] px-[var(--btn-px-sm)] [--btn-icon-size:0.875rem] has-[>svg]:px-[calc(var(--btn-px-sm)-0.125rem)]",
          typeScale.button
        ),
        default: cn(
          "h-[var(--btn-height-md)] gap-[var(--btn-gap-md)] px-[var(--btn-px-md)] [--btn-icon-size:1rem] has-[>svg]:px-[calc(var(--btn-px-md)-0.25rem)]",
          typeScale.button
        ),
        lg: cn(
          "h-[var(--btn-height-lg)] gap-[var(--btn-gap-lg)] px-[var(--btn-px-lg)] [--btn-icon-size:1.25rem] has-[>svg]:px-[calc(var(--btn-px-lg)-0.25rem)]",
          typeScale["button-lg"]
        ),
        "icon-sm":
          "size-[var(--btn-height-sm)] gap-0 p-0 [--btn-icon-size:0.875rem]",
        icon: "size-[var(--btn-height-md)] gap-0 p-0 [--btn-icon-size:1rem]",
        "icon-lg":
          "size-[var(--btn-height-lg)] gap-0 p-0 [--btn-icon-size:1.25rem]",
      },
    },
    compoundVariants: [
      {
        variant: "default",
        surface: "brand",
        className:
          "bg-white text-brand-dark shadow-glow-sm hover:bg-brand-light hover:text-brand-dark hover:shadow-glow-primary active:bg-brand-light/90",
      },
      {
        variant: ["secondary", "outline"],
        surface: "brand",
        className:
          "border-white/40 bg-transparent text-white shadow-none hover:border-white/60 hover:bg-white/10 hover:text-white hover:shadow-[0_0_0_1px_rgb(255_255_255_/_0.35),0_0_18px_-4px_rgb(255_255_255_/_0.35)] active:bg-white/15",
      },
      {
        variant: "ghost",
        surface: "brand",
        className:
          "text-white hover:bg-white/10 hover:text-white active:bg-white/15",
      },
      {
        variant: "link",
        surface: "brand",
        className: "text-white hover:text-white/90",
      },
    ],
    defaultVariants: {
      variant: "default",
      surface: "default",
      size: "default",
    },
  }
)

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

  return (
    <Comp
      data-slot="button"
      data-variant={variant ?? "default"}
      data-surface={surface ?? "default"}
      data-size={size ?? "default"}
      className={cn(buttonVariants({ variant, size, surface }), className)}
      {...props}
    />
  )
}

export { Button, buttonVariants }