npx -y create-pinecone-app@latest --template pinecone-assistant

'use server'

import { createStreamableValue } from '@ai-sdk/rsc'
import { EventSource } from 'extended-eventsource';

type Message = {
  role: string;
  content: string;
}

export async function chat(messages: Message[]) {

  // Create an initial stream, which we'll populate with events from the Pinecone Assistants API
  const stream = createStreamableValue()

  // Construct the full URL to the Pinecone Assistant API for the specific assistant
  // indicated by the user
  const url = `${process.env.PINECONE_ASSISTANT_URL}/${process.env.PINECONE_ASSISTANT_NAME}/chat/completions`

  const eventSource = new EventSource(url, {
    method: 'POST',
    body: JSON.stringify({
      stream: true,
      messages,
    }),
    headers: {
      Authorization: `Bearer ${process.env.PINECONE_API_KEY}`,
      'X-Project-Id': process.env.PINECONE_ASSISTANT_ID!,
    },
    disableRetry: true,
  });

  // When we receive a new message from the Pinecone Assistant API, we update the stream
  // unless the Assistant is done, in which case we close the stream
  eventSource.onmessage = (event: MessageEvent) => {
    const message = JSON.parse(event.data)
    if (message?.choices[0]?.finish_reason) {
      eventSource.close();
      stream.done();
    } else {
      stream.update(event.data)
    }
  };

  eventSource.onerror = (error) => {
    console.error('EventSource error:', error);
    eventSource.close();
  };

  return { object: stream.value }
}

const handleChat = async () => {
    if (!input.trim()) return;

    const newUserMessage: Message = {
      id: uuidv4(), // Generate a unique ID
      role: 'user',
      content: input,
      timestamp: new Date().toISOString()
    };

    setMessages(prevMessages => [...prevMessages, newUserMessage]);
    setInput('');
    setIsStreaming(true);

    try {
      const { object } = await chat([newUserMessage]);
      let accumulatedContent = '';
      const newAssistantMessage: Message = {
        id: uuidv4(),
        role: 'assistant',
        content: '',
        timestamp: new Date().toISOString(),
        references: []
      };

      setMessages(prevMessages => [...prevMessages, newAssistantMessage]);

      // Process the response stream from the Assistant that is created in the ./actions.ts Server action
      for await (const chunk of readStreamableValue(object)) {
        try {
          const data = JSON.parse(chunk);
          const content = data.choices[0]?.delta?.content;

          if (content) {
            accumulatedContent += content;
          }

          setMessages(prevMessages => {
            const updatedMessages = [...prevMessages];
            const lastMessage = updatedMessages[updatedMessages.length - 1];
            lastMessage.content = accumulatedContent;
            return updatedMessages;
          });

        } catch (error) {
          console.error('Error parsing chunk:', error);
        }
      }

      // Extract references after the full message is received
      const extractedReferences = extractReferences(accumulatedContent);
      setReferencedFiles(extractedReferences);

    } catch (error) {
      console.error('Error in chat:', error);
      setError('An error occurred while chatting.');
    } finally {
      setIsStreaming(false);
    }
  };