feat: update Azure Cosmos DB integration and improve error handling in GraphQL API

Author: danieldanielecki

.env.example

@@ -1,4 +1,3 @@
-AZURE_COSMOSDB_CONTAINER=
 AZURE_COSMOSDB_DATABASE=
 AZURE_COSMOSDB_ENDPOINT=
 AZURE_COSMOSDB_KEY=

.gitignore

@@ -49,3 +49,9 @@ next-env.d.ts
 
 bundles
 .env
+
+# service worker
+sw.js
+sw.js.map
+workbox-*.js
+workbox-*.js.map

app/api/graphql/route.ts

@@ -1,4 +1,3 @@
-import { CosmosContainer } from "@azure-fundamentals/lib/graphql/cosmos-client";
 import {
   CombinedQuestionsDataSource,
   RepoQuestionsDataSource,
@@ -26,7 +25,7 @@ const handler = startServerAndCreateNextHandler(server, {
     if (process.env.AZURE_COSMOSDB_ENDPOINT) {
       return {
         dataSources: {
-          questionsDB: CombinedQuestionsDataSource(CosmosContainer()),
+          questionsDB: CombinedQuestionsDataSource(),
         },
       };
     } else {
@@ -54,4 +53,24 @@ const handler = startServerAndCreateNextHandler(server, {
   },
 });
 
-export { handler as GET, handler as POST };
+// Wrap the handler to handle errors
+const wrappedHandler = async (req: Request) => {
+  try {
+    return await handler(req);
+  } catch (error) {
+    console.error("GraphQL Error:", error);
+    return new Response(
+      JSON.stringify({
+        errors: [{ message: "Internal server error" }],
+      }),
+      {
+        status: 500,
+        headers: {
+          "Content-Type": "application/json",
+        },
+      },
+    );
+  }
+};
+
+export { wrappedHandler as GET, wrappedHandler as POST };

lib/graphql/cosmos-client.tsx

@@ -1,14 +1,36 @@
 import { CosmosClient } from "@azure/cosmos";
 
-export const CosmosContainer = () => {
+export const getDatabase = () => {
   const client = new CosmosClient({
     endpoint: process.env.AZURE_COSMOSDB_ENDPOINT!,
     key: process.env.AZURE_COSMOSDB_KEY!,
   });
 
-  const container = client
-    .database(process.env.AZURE_COSMOSDB_DATABASE!)
-    .container(process.env.AZURE_COSMOSDB_CONTAINER!);
+  return client.database(process.env.AZURE_COSMOSDB_DATABASE!);
+};
+
+export const getContainer = async (containerName: string) => {
+  const database = getDatabase();
 
-  return container;
+  // Try to create container if it doesn't exist
+  try {
+    const { container } = await database.containers.createIfNotExists({
+      id: containerName,
+      partitionKey: {
+        paths: ["/id"],
+      },
+    });
+    return container;
+  } catch (error: any) {
+    // If container creation fails, try to get the existing container
+    if (error.code === 409) {
+      console.log(
+        `Container ${containerName} already exists, using existing container`,
+      );
+      return database.container(containerName);
+    } else {
+      console.error("Error creating container:", error);
+      throw error;
+    }
+  }
 };

lib/graphql/questionsDataSource.tsx

@@ -1,5 +1,6 @@
 import { Container } from "@azure/cosmos";
 import { fetchQuestions } from "./repoQuestions";
+import { getContainer } from "./cosmos-client";
 
 export const QuestionsDataSource = (container: Container) => {
   return {
@@ -67,18 +68,25 @@ export const RepoQuestionsDataSource = (container: any) => {
   };
 };
 
-export const CombinedQuestionsDataSource = (container: Container) => {
+export const CombinedQuestionsDataSource = () => {
   return {
     async getQuestion(id: string, link: string) {
       try {
+        // Extract exam name from URL and create a safe container name
+        const segments = link.split("/");
+        const examName = segments[segments.length - 3]
+          .replace(/-/g, "_")
+          .toLowerCase();
+        const examContainer = await getContainer(examName);
+
         // Try GitHub first
         const questions = await fetchQuestions(link);
         if (questions) {
           const question = questions.find((q: any) => q.id === id);
           if (question) {
-            // Upload to Cosmos DB for future use
+            // Upload to exam-specific container
             try {
-              await container.items.upsert(question);
+              await examContainer.items.upsert(question);
             } catch (err) {
               console.warn("Failed to upload question to Cosmos DB:", err);
             }
@@ -91,7 +99,7 @@ export const CombinedQuestionsDataSource = (container: Container) => {
           query: "SELECT * FROM c WHERE c.id = @id",
           parameters: [{ name: "@id", value: id }],
         };
-        const { resources: items } = await container.items
+        const { resources: items } = await examContainer.items
           .query(querySpec)
           .fetchAll();
         return items[0];
@@ -102,13 +110,20 @@ export const CombinedQuestionsDataSource = (container: Container) => {
 
     async getQuestions(link: string) {
       try {
+        // Extract exam name from URL and create a safe container name
+        const segments = link.split("/");
+        const examName = segments[segments.length - 3]
+          .replace(/-/g, "_")
+          .toLowerCase();
+        const examContainer = await getContainer(examName);
+
         // Try GitHub first
         const questions = await fetchQuestions(link);
         if (questions) {
-          // Upload all questions to Cosmos DB
+          // Upload all questions to exam-specific container
           try {
             for (const question of questions) {
-              await container.items.upsert(question);
+              await examContainer.items.upsert(question);
             }
           } catch (err) {
             console.warn("Failed to upload questions to Cosmos DB:", err);
@@ -120,7 +135,7 @@ export const CombinedQuestionsDataSource = (container: Container) => {
         const querySpec = {
           query: "SELECT VALUE COUNT(c.id) FROM c",
         };
-        const { resources: items } = await container.items
+        const { resources: items } = await examContainer.items
           .query(querySpec)
           .fetchAll();
         return { count: items[0] };
@@ -131,16 +146,23 @@ export const CombinedQuestionsDataSource = (container: Container) => {
 
     async getRandomQuestions(range: number, link: string) {
       try {
+        // Extract exam name from URL and create a safe container name
+        const segments = link.split("/");
+        const examName = segments[segments.length - 3]
+          .replace(/-/g, "_")
+          .toLowerCase();
+        const examContainer = await getContainer(examName);
+
         // Try GitHub first
         const questions = await fetchQuestions(link);
         if (questions) {
           const shuffled = [...questions].sort(() => 0.5 - Math.random());
           const selected = shuffled.slice(0, range);
 
-          // Upload selected questions to Cosmos DB
+          // Upload selected questions to exam-specific container
           try {
             for (const question of selected) {
-              await container.items.upsert(question);
+              await examContainer.items.upsert(question);
             }
           } catch (err) {
             console.warn("Failed to upload questions to Cosmos DB:", err);
@@ -153,7 +175,7 @@ export const CombinedQuestionsDataSource = (container: Container) => {
         const querySpec = {
           query: "SELECT * FROM c",
         };
-        const { resources: items } = await container.items
+        const { resources: items } = await examContainer.items
           .query(querySpec)
           .fetchAll();
         const shuffled = [...items].sort(() => 0.5 - Math.random());

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "practice-exams-platform",
-  "version": "1.2.0",
+  "version": "1.3.0",
   "private": true,
   "engines": {
     "node": "20.x"