frontend/src/components/ui/message-scroller.tsx

import * as React from "react"
import {
  MessageScroller as MessageScrollerPrimitive,
  useMessageScroller,
  useMessageScrollerScrollable,
  useMessageScrollerVisibility,
} from "@shadcn/react/message-scroller"
import { ArrowDown } from "lucide-react"

import { Button } from "@/components/ui/button"
import { cn } from "@/shared/lib/cn"

function MessageScrollerProvider(
  props: React.ComponentProps<typeof MessageScrollerPrimitive.Provider>
) {
  return <MessageScrollerPrimitive.Provider {...props} />
}

function MessageScroller({
  className,
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Root>) {
  return (
    <MessageScrollerPrimitive.Root
      data-slot="message-scroller"
      className={cn("group/message-scroller relative flex size-full min-h-0 flex-col overflow-hidden", className)}
      {...props}
    />
  )
}

function MessageScrollerViewport({
  className,
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Viewport>) {
  return (
    <MessageScrollerPrimitive.Viewport
      data-slot="message-scroller-viewport"
      className={cn("size-full min-h-0 min-w-0 overflow-y-auto overscroll-contain", className)}
      {...props}
    />
  )
}

function MessageScrollerContent({
  className,
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Content>) {
  return (
    <MessageScrollerPrimitive.Content
      data-slot="message-scroller-content"
      className={cn("flex min-h-full flex-col gap-6", className)}
      {...props}
    />
  )
}

function MessageScrollerItem({
  className,
  scrollAnchor = false,
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Item>) {
  return (
    <MessageScrollerPrimitive.Item
      data-slot="message-scroller-item"
      scrollAnchor={scrollAnchor}
      className={cn("min-w-0 shrink-0 [contain-intrinsic-size:auto_10rem] [content-visibility:auto]", className)}
      {...props}
    />
  )
}

function MessageScrollerButton({
  direction = "end",
  className,
  children,
  render,
  variant = "secondary",
  size = "icon",
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Button> &
  Pick<React.ComponentProps<typeof Button>, "variant" | "size">) {
  return (
    <MessageScrollerPrimitive.Button
      data-slot="message-scroller-button"
      data-direction={direction}
      direction={direction}
      className={cn(
        "absolute start-1/2 z-10 -translate-x-1/2 border border-border bg-background text-foreground shadow-sm transition-[translate,scale,opacity] duration-200 hover:bg-muted data-[active=false]:pointer-events-none data-[active=false]:scale-95 data-[active=false]:opacity-0 data-[active=true]:translate-y-0 data-[active=true]:scale-100 data-[active=true]:opacity-100 data-[direction=end]:bottom-4 data-[direction=end]:data-[active=false]:translate-y-full data-[direction=start]:top-4 data-[direction=start]:data-[active=false]:-translate-y-full data-[direction=start]:[&_svg]:rotate-180",
        className
      )}
      render={render ?? <Button variant={variant} size={size} />}
      {...props}
    >
      {children ?? <ArrowDown />}
    </MessageScrollerPrimitive.Button>
  )
}

export {
  MessageScrollerProvider,
  MessageScroller,
  MessageScrollerViewport,
  MessageScrollerContent,
  MessageScrollerItem,
  MessageScrollerButton,
  useMessageScroller,
  useMessageScrollerScrollable,
  useMessageScrollerVisibility,
}