feat: implement basic web app

frontend/src/components/workspace/message-list/message-list-item.tsx

@@ -0,0 +1,71 @@
+import type { Message } from "@langchain/langgraph-sdk";
+import { memo } from "react";
+
+import {
+  Message as AIElementMessage,
+  MessageContent as AIElementMessageContent,
+  MessageResponse as AIElementMessageResponse,
+} from "@/components/ai-elements/message";
+import { useRehypeSplitWordsIntoSpans } from "@/core/rehype";
+import { cn } from "@/lib/utils";
+
+import { MessageGroup } from "./message-group";
+import { extractContentFromMessage, hasReasoning, hasToolCalls } from "./utils";
+
+export function MessageListItem({
+  className,
+  message,
+  messagesInGroup,
+  isLoading,
+}: {
+  className?: string;
+  message: Message;
+  messagesInGroup: Message[];
+  isLoading?: boolean;
+}) {
+  return (
+    <AIElementMessage
+      className={cn("relative", "group/conversation-message", className)}
+      from={message.type === "human" ? "user" : "assistant"}
+    >
+      <MessageContent
+        className={className}
+        message={message}
+        messagesInGroup={messagesInGroup}
+        isLoading={isLoading}
+      />
+    </AIElementMessage>
+  );
+}
+
+function MessageContent_({
+  className,
+  message,
+  messagesInGroup,
+  isLoading = false,
+}: {
+  className?: string;
+  message: Message;
+  messagesInGroup: Message[];
+  isLoading?: boolean;
+}) {
+  const rehypePlugins = useRehypeSplitWordsIntoSpans(isLoading);
+  return (
+    <AIElementMessageContent className={className}>
+      {hasReasoning(message) && (
+        <MessageGroup
+          className="mb-2"
+          messages={[message]}
+          isLoading={isLoading}
+        />
+      )}
+      <AIElementMessageResponse rehypePlugins={rehypePlugins}>
+        {extractContentFromMessage(message)}
+      </AIElementMessageResponse>
+      {hasToolCalls(message) && (
+        <MessageGroup messages={messagesInGroup} isLoading={isLoading} />
+      )}
+    </AIElementMessageContent>
+  );
+}
+const MessageContent = memo(MessageContent_);