Fix generating title from messages (#442)

lib/utils.ts

@@ -1,6 +1,15 @@
+import {
+  CoreMessage,
+  CoreToolMessage,
+  generateId,
+  Message,
+  ToolInvocation,
+} from "ai";
 import { clsx, type ClassValue } from "clsx";
 import { twMerge } from "tailwind-merge";
 
+import { Chat } from "@/db/schema";
+
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
@@ -41,3 +50,89 @@ export function generateUUID(): string {
     return v.toString(16);
   });
 }
+
+function addToolMessageToChat({
+  toolMessage,
+  messages,
+}: {
+  toolMessage: CoreToolMessage;
+  messages: Array<Message>;
+}): Array<Message> {
+  return messages.map((message) => {
+    if (message.toolInvocations) {
+      return {
+        ...message,
+        toolInvocations: message.toolInvocations.map((toolInvocation) => {
+          const toolResult = toolMessage.content.find(
+            (tool) => tool.toolCallId === toolInvocation.toolCallId,
+          );
+
+          if (toolResult) {
+            return {
+              ...toolInvocation,
+              state: "result",
+              result: toolResult.result,
+            };
+          }
+
+          return toolInvocation;
+        }),
+      };
+    }
+
+    return message;
+  });
+}
+
+export function convertToUIMessages(
+  messages: Array<CoreMessage>,
+): Array<Message> {
+  return messages.reduce((chatMessages: Array<Message>, message) => {
+    if (message.role === "tool") {
+      return addToolMessageToChat({
+        toolMessage: message as CoreToolMessage,
+        messages: chatMessages,
+      });
+    }
+
+    let textContent = "";
+    let toolInvocations: Array<ToolInvocation> = [];
+
+    if (typeof message.content === "string") {
+      textContent = message.content;
+    } else if (Array.isArray(message.content)) {
+      for (const content of message.content) {
+        if (content.type === "text") {
+          textContent += content.text;
+        } else if (content.type === "tool-call") {
+          toolInvocations.push({
+            state: "call",
+            toolCallId: content.toolCallId,
+            toolName: content.toolName,
+            args: content.args,
+          });
+        }
+      }
+    }
+
+    chatMessages.push({
+      id: generateId(),
+      role: message.role,
+      content: textContent,
+      toolInvocations,
+    });
+
+    return chatMessages;
+  }, []);
+}
+
+export function getTitleFromChat(chat: Chat) {
+  const messages = convertToUIMessages(chat.messages as Array<CoreMessage>);
+  const firstMessage = messages[0];
+
+  if (!firstMessage) {
+    return "Untitled";
+  }
+
+  return firstMessage.content;
+}