components/artifact-messages.tsx

import { PreviewMessage, ThinkingMessage } from './message';
import type { Vote } from '@/lib/db/schema';
import { memo } from 'react';
import equal from 'fast-deep-equal';
import type { UIArtifact } from './artifact';
import type { UseChatHelpers } from '@ai-sdk/react';
import { motion } from 'framer-motion';
import { useMessages } from '@/hooks/use-messages';
import type { ChatMessage } from '@/lib/types';

interface ArtifactMessagesProps {
  chatId: string;
  status: UseChatHelpers<ChatMessage>['status'];
  votes: Array<Vote> | undefined;
  messages: ChatMessage[];
  setMessages: UseChatHelpers<ChatMessage>['setMessages'];
  regenerate: UseChatHelpers<ChatMessage>['regenerate'];
  isReadonly: boolean;
  artifactStatus: UIArtifact['status'];
}

function PureArtifactMessages({
  chatId,
  status,
  votes,
  messages,
  setMessages,
  regenerate,
  isReadonly,
}: ArtifactMessagesProps) {
  const {
    containerRef: messagesContainerRef,
    endRef: messagesEndRef,
    onViewportEnter,
    onViewportLeave,
    hasSentMessage,
  } = useMessages({
    chatId,
    status,
  });

  return (
    <div
      ref={messagesContainerRef}
      className="flex flex-col gap-4 h-full items-center overflow-y-scroll px-4 pt-20"
    >
      {messages.map((message, index) => (
        <PreviewMessage
          chatId={chatId}
          key={message.id}
          message={message}
          isLoading={status === 'streaming' && index === messages.length - 1}
          vote={
            votes
              ? votes.find((vote) => vote.messageId === message.id)
              : undefined
          }
          setMessages={setMessages}
          regenerate={regenerate}
          isReadonly={isReadonly}
          requiresScrollPadding={
            hasSentMessage && index === messages.length - 1
          }
        />
      ))}

      {status === 'submitted' &&
        messages.length > 0 &&
        messages[messages.length - 1].role === 'user' && <ThinkingMessage />}

      <motion.div
        ref={messagesEndRef}
        className="shrink-0 min-w-[24px] min-h-[24px]"
        onViewportLeave={onViewportLeave}
        onViewportEnter={onViewportEnter}
      />
    </div>
  );
}

function areEqual(
  prevProps: ArtifactMessagesProps,
  nextProps: ArtifactMessagesProps,
) {
  if (
    prevProps.artifactStatus === 'streaming' &&
    nextProps.artifactStatus === 'streaming'
  )
    return true;

  if (prevProps.status !== nextProps.status) return false;
  if (prevProps.status && nextProps.status) return false;
  if (prevProps.messages.length !== nextProps.messages.length) return false;
  if (!equal(prevProps.votes, nextProps.votes)) return false;

  return true;
}

export const ArtifactMessages = memo(PureArtifactMessages, areEqual);