From 905eac6c4f9c08026f64de5714bbb9ca36ac07e9 Mon Sep 17 00:00:00 2001
From: Steven Nguyen <stnguyen90@users.noreply.github.com>
Date: Tue, 19 Sep 2023 11:58:56 -0700
Subject: [PATCH] Update assistant to not crash on startup.

If the _APP_ASSISTANT_OPENAI_API_KEY env var was not set, the assistant
would crash. This prevents that from happening and returns an error
message if the key is not set.
---
 embeddings.js | 31 ++++++++++++++++++-------------
 main.js       | 19 ++++++++++++++++---
 2 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/embeddings.js b/embeddings.js
index 7900e9d..cb475f0 100644
--- a/embeddings.js
+++ b/embeddings.js
@@ -30,20 +30,25 @@ async function chunk_sources(sources) {
   return source_chunks;
 }
 
-const sources = globSync("docs/*.json").map((filename) => {
-  const source = JSON.parse(fs.readFileSync(filename));
-  return new Document({
-    pageContent: source.page_content,
-    metadata: source.metadata,
+
+
+export const initializeSearchIndex = async () => {
+  const sources = globSync("docs/*.json").map((filename) => {
+    const source = JSON.parse(fs.readFileSync(filename));
+    return new Document({
+      pageContent: source.page_content,
+      metadata: source.metadata,
+    });
   });
-});
-
-export const search_index = FaissStore.fromDocuments(
-  await chunk_sources(sources),
-  new OpenAIEmbeddings({
-    openAIApiKey: process.env._APP_ASSISTANT_OPENAI_API_KEY,
-  })
-);
+  
+  return FaissStore.fromDocuments(
+    await chunk_sources(sources),
+    new OpenAIEmbeddings({
+      openAIApiKey: process.env._APP_ASSISTANT_OPENAI_API_KEY,
+    })
+  );
+}
+
 export const getChain = (res) => {
   return loadQAStuffChain(
     new OpenAIChat({
diff --git a/main.js b/main.js
index b8ad6d4..b1e1fbe 100644
--- a/main.js
+++ b/main.js
@@ -1,7 +1,7 @@
 import bodyParser from "body-parser";
 import cors from "cors";
 import express from "express";
-import { getChain, search_index } from "./embeddings.js";
+import { getChain, initializeSearchIndex } from "./embeddings.js";
 import "dotenv/config";
 
 const app = express();
@@ -12,6 +12,8 @@ app.use(
 );
 app.use(bodyParser.raw({ inflate: true, type: "*/*" }));
 
+let searchIndex = null;
+
 const port = 3003;
 
 const template = (
@@ -22,6 +24,10 @@ reference docs. For each question show code examples when applicable.
 ${prompt}`;
 
 app.post("/", async (req, res) => {
+  if (!searchIndex) {
+    res.status(500).send("Search index not initialized");
+    return;
+  }
   // raw to text
   const decoder = new TextDecoder();
   const text = decoder.decode(req.body);
@@ -30,13 +36,20 @@ app.post("/", async (req, res) => {
 
   const chain = await getChain(res);
   await chain.call({
-    input_documents: await (await search_index).similaritySearch(templated, 4),
+    input_documents: await searchIndex.similaritySearch(templated, 4),
     question: templated,
   });
 
   res.end();
 });
 
-app.listen(port, () => {
+app.listen(port, async () => {
   console.log(`Started server on port: ${port}`);
+  console.log('Initializing search index...');
+  try {
+    searchIndex = await initializeSearchIndex();
+    console.log('Search index initialized');
+  } catch (e) {
+    console.error(e);
+  }
 });