agent_backend/components/ui/message-scroller.tsx

'use client';

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

import { cn } from '@/lib/utils';
import { Button } from '@/components/ui/button';
import { ArrowDownIcon } from 'lucide-react';

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 scroll-fade-b scrollbar-thin scrollbar-gutter-stable overflow-y-auto overscroll-contain contain-content data-autoscrolling:scrollbar-thumb-transparent data-autoscrolling:scrollbar-track-transparent',
        className,
      )}
      {...props}
    />
  );
}

function MessageScrollerContent({
  className,
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Content>) {
  return (
    <MessageScrollerPrimitive.Content
      data-slot="message-scroller-content"
      className={cn('gap-6 flex h-max min-h-full flex-col', 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-sm',
  ...props
}: React.ComponentProps<typeof MessageScrollerPrimitive.Button> &
  Pick<React.ComponentProps<typeof Button>, 'variant' | 'size'>) {
  return (
    <MessageScrollerPrimitive.Button
      data-slot="message-scroller-button"
      data-direction={direction}
      data-variant={variant}
      data-size={size}
      direction={direction}
      className={cn(
        'absolute inset-s-1/2 -translate-x-1/2 border-border bg-background text-foreground transition-[translate,scale,opacity] duration-200 hover:bg-muted hover:text-foreground data-[active=false]:pointer-events-none data-[active=false]:scale-95 data-[active=false]:opacity-0 data-[active=false]:duration-400 data-[active=false]:ease-[cubic-bezier(0.7,0,0.84,0)] data-[active=true]:translate-y-0 data-[active=true]:scale-100 data-[active=true]:opacity-100 data-[active=true]:ease-[cubic-bezier(0.23,1,0.32,1)] 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 rtl:translate-x-1/2 data-[direction=start]:[&_svg]:rotate-180',
        className,
      )}
      render={render ?? <Button variant={variant} size={size} />}
      {...props}
    >
      {children ?? (
        <>
          <ArrowDownIcon />
          <span className="sr-only">
            {direction === 'end' ? 'Scroll to end' : 'Scroll to start'}
          </span>
        </>
      )}
    </MessageScrollerPrimitive.Button>
  );
}

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