Merge pull request #60 from Ditectrev/feature/AzureCosmosDB

feat: Azure CosmosDB as a fallback from repos

Author: danieldanielecki

.env.example

@@ -0,0 +1,3 @@
+AZURE_COSMOSDB_DATABASE=
+AZURE_COSMOSDB_ENDPOINT=
+AZURE_COSMOSDB_KEY=

.gitignore

@@ -46,3 +46,12 @@ next-env.d.ts
 **/public/sw.js
 **/public/worker-*.js
 **/public/sw.js.map
+
+bundles
+.env
+
+# service worker
+sw.js
+sw.js.map
+workbox-*.js
+workbox-*.js.map

app/api/graphql/route.ts

@@ -1,11 +1,12 @@
-// import { CosmosContainer } from "@azure-fundamentals/src/graphql/cosmos-client";
-// import { QuestionsDataSource, LocalQuestionsDataSource } from "@azure-fundamentals/src/graphql/questionsDataSource";
+import {
+  CombinedQuestionsDataSource,
+  RepoQuestionsDataSource,
+} from "@azure-fundamentals/lib/graphql/questionsDataSource";
 import { ApolloServer, BaseContext } from "@apollo/server";
 import { startServerAndCreateNextHandler } from "@as-integrations/next";
 import typeDefs from "@azure-fundamentals/lib/graphql/schemas";
 import resolvers from "@azure-fundamentals/lib/graphql/resolvers";
-//import { RepoQuestionsDataSource } from "@azure-fundamentals/lib/graphql/questionsDataSource";
-//import { FetchQuestions } from "@azure-fundamentals/lib/graphql/repoQuestions";
+import { fetchQuestions } from "@azure-fundamentals/lib/graphql/repoQuestions";
 
 interface ContextValue {
   dataSources: {
@@ -19,22 +20,57 @@ const server = new ApolloServer<ContextValue>({
   introspection: process.env.NODE_ENV !== "production",
 });
 
-//const questions = await FetchQuestions();
-
-const handler = startServerAndCreateNextHandler(
-  server,
-  /*{
+const handler = startServerAndCreateNextHandler(server, {
   context: async () => {
-    return {
-      dataSources: {
-        // questionsDB: process.env.AZURE_COSMOSDB_ENDPOINT
-        //   ? QuestionsDataSource(CosmosContainer())
-        //   : LocalQuestionsDataSource(questions),
-        questionsDB: RepoQuestionsDataSource(questions),
-      },
-    };
+    if (process.env.AZURE_COSMOSDB_ENDPOINT) {
+      return {
+        dataSources: {
+          questionsDB: CombinedQuestionsDataSource(),
+        },
+      };
+    } else {
+      // Fallback to GitHub-only data source
+      return {
+        dataSources: {
+          questionsDB: {
+            getQuestion: async (id: string, link: string) => {
+              const questions = await fetchQuestions(link);
+              return questions?.find((q: any) => q.id === id);
+            },
+            getQuestions: async (link: string) => {
+              const questions = await fetchQuestions(link);
+              return { count: questions?.length || 0 };
+            },
+            getRandomQuestions: async (range: number, link: string) => {
+              const questions = await fetchQuestions(link);
+              const shuffled = questions?.sort(() => 0.5 - Math.random());
+              return shuffled?.slice(0, range) || [];
+            },
+          },
+        },
+      };
+    }
   },
-}*/
-);
+});
+
+// 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 { handler as GET, handler as POST };
+export { wrappedHandler as GET, wrappedHandler as POST };

app/layout.tsx

@@ -1,11 +1,17 @@
 import { type ReactNode } from "react";
-import { type Metadata } from "next";
+import { type Metadata, type Viewport } from "next";
 import TopNav from "@azure-fundamentals/components/TopNav";
 import Footer from "@azure-fundamentals/components/Footer";
 import ApolloProvider from "@azure-fundamentals/components/ApolloProvider";
 import Cookie from "@azure-fundamentals/components/Cookie";
 import "styles/globals.css";
 
+export const viewport: Viewport = {
+  themeColor: "#3f51b5",
+  width: "device-width",
+  initialScale: 1,
+};
+
 export const metadata: Metadata = {
   appleWebApp: {
     capable: true,
@@ -71,7 +77,6 @@ export const metadata: Metadata = {
     follow: true,
     index: true,
   },
-  themeColor: "#3f51b5",
   title: {
     default: "🧪 Practice Exams Platform | Ditectrev",
     template: "🧪 Practice Exams Platform | Ditectrev",
@@ -90,10 +95,6 @@ export const metadata: Metadata = {
     site: "@ditectrev",
     title: "🧪 Practice Exams Platform | Ditectrev",
   },
-  viewport: {
-    initialScale: 1,
-    width: "device-width",
-  },
 };
 
 type RootLayoutProps = {

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 getQuestionsContainer = async () => {
+  const database = getDatabase();
 
-  return container;
+  // Try to create container if it doesn't exist
+  try {
+    const { container } = await database.containers.createIfNotExists({
+      id: "questions",
+      partitionKey: {
+        paths: ["/examId"],
+      },
+    });
+    return container;
+  } catch (error: any) {
+    // If container creation fails, try to get the existing container
+    if (error.code === 409) {
+      console.log(
+        `Container questions already exists, using existing container`,
+      );
+      return database.container("questions");
+    } else {
+      console.error("Error creating container:", error);
+      throw error;
+    }
+  }
 };

lib/graphql/questionsDataSource.tsx

@@ -1,4 +1,6 @@
-/*import { Container } from "@azure/cosmos";
+import { Container } from "@azure/cosmos";
+import { fetchQuestions } from "./repoQuestions";
+import { getQuestionsContainer } from "./cosmos-client";
 
 export const QuestionsDataSource = (container: Container) => {
   return {
@@ -38,7 +40,7 @@ export const QuestionsDataSource = (container: Container) => {
     },
   };
 };
-*/
+
 export const RepoQuestionsDataSource = (container: any) => {
   return {
     async getQuestion(id: string) {
@@ -65,3 +67,150 @@ export const RepoQuestionsDataSource = (container: any) => {
     },
   };
 };
+
+// Helper function to extract exam ID from URL
+const extractExamId = (link: string): string => {
+  const segments = link.split("/");
+  return segments[segments.length - 3].replace(/-/g, "_").toLowerCase();
+};
+
+export const CombinedQuestionsDataSource = () => {
+  return {
+    async getQuestion(id: string, link: string) {
+      try {
+        const examId = extractExamId(link);
+        const questionsContainer = await getQuestionsContainer();
+
+        // Try Cosmos DB first (most efficient)
+        const querySpec = {
+          query: "SELECT * FROM c WHERE c.id = @id AND c.examId = @examId",
+          parameters: [
+            { name: "@id", value: id },
+            { name: "@examId", value: examId },
+          ],
+        };
+        const { resources: items } = await questionsContainer.items
+          .query(querySpec)
+          .fetchAll();
+
+        if (items.length > 0) {
+          return items[0];
+        }
+
+        // Fallback to GitHub if not found in database
+        const questions = await fetchQuestions(link);
+        if (questions) {
+          const question = questions.find((q: any) => q.id === id);
+          if (question) {
+            // Add examId to the question document and upload to database
+            const questionWithExamId = {
+              ...question,
+              examId: examId,
+            };
+
+            try {
+              await questionsContainer.items.upsert(questionWithExamId);
+            } catch (err) {
+              console.warn("Failed to upload question to Cosmos DB:", err);
+            }
+            return question;
+          }
+        }
+
+        return null;
+      } catch (err) {
+        throw new Error("Error fetching question: " + err);
+      }
+    },
+
+    async getQuestions(link: string) {
+      try {
+        const examId = extractExamId(link);
+        const questionsContainer = await getQuestionsContainer();
+
+        // Try Cosmos DB first
+        const querySpec = {
+          query: "SELECT VALUE COUNT(c.id) FROM c WHERE c.examId = @examId",
+          parameters: [{ name: "@examId", value: examId }],
+        };
+        const { resources: items } = await questionsContainer.items
+          .query(querySpec)
+          .fetchAll();
+
+        if (items[0] > 0) {
+          return { count: items[0] };
+        }
+
+        // Fallback to GitHub if no questions found in database
+        const questions = await fetchQuestions(link);
+        if (questions) {
+          // Upload all questions to database (only if they don't exist)
+          try {
+            for (const question of questions) {
+              const questionWithExamId = {
+                ...question,
+                examId: examId,
+              };
+              await questionsContainer.items.upsert(questionWithExamId);
+            }
+          } catch (err) {
+            console.warn("Failed to upload questions to Cosmos DB:", err);
+          }
+          return { count: questions.length };
+        }
+
+        return { count: 0 };
+      } catch (err) {
+        throw new Error("Error fetching questions: " + err);
+      }
+    },
+
+    async getRandomQuestions(range: number, link: string) {
+      try {
+        const examId = extractExamId(link);
+        const questionsContainer = await getQuestionsContainer();
+
+        // Try Cosmos DB first
+        const querySpec = {
+          query: "SELECT * FROM c WHERE c.examId = @examId",
+          parameters: [{ name: "@examId", value: examId }],
+        };
+        const { resources: items } = await questionsContainer.items
+          .query(querySpec)
+          .fetchAll();
+
+        if (items.length > 0) {
+          // Questions exist in database, return random selection
+          const shuffled = [...items].sort(() => 0.5 - Math.random());
+          return shuffled.slice(0, range);
+        }
+
+        // Fallback to GitHub if no questions found in database
+        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 database (only if they don't exist)
+          try {
+            for (const question of selected) {
+              const questionWithExamId = {
+                ...question,
+                examId: examId,
+              };
+              await questionsContainer.items.upsert(questionWithExamId);
+            }
+          } catch (err) {
+            console.warn("Failed to upload questions to Cosmos DB:", err);
+          }
+
+          return selected;
+        }
+
+        return [];
+      } catch (err) {
+        throw new Error("Error fetching random questions: " + err);
+      }
+    },
+  };
+};

lib/graphql/resolvers.tsx

@@ -7,25 +7,21 @@ const resolvers = {
       { link }: { link: string },
       { dataSources }: { dataSources: any },
     ) => {
-      const response = await fetchQuestions(link);
-      return { count: response?.length };
+      return dataSources.questionsDB.getQuestions(link);
     },
     questionById: async (
       _: unknown,
       { id, link }: { id: string; link: string },
       { dataSources }: { dataSources: any },
     ) => {
-      const response = await fetchQuestions(link);
-      return response?.filter((el: any) => el.id === id)[0];
+      return dataSources.questionsDB.getQuestion(id, link);
     },
     randomQuestions: async (
       _: unknown,
       { range, link }: { range: number; link: string },
       { dataSources }: { dataSources: any },
     ) => {
-      const response = await fetchQuestions(link);
-      const shuffled = response?.sort(() => 0.5 - Math.random());
-      return shuffled?.slice(0, range);
+      return dataSources.questionsDB.getRandomQuestions(range, link);
     },
   },
 };

lib/graphql/schemas.tsx

@@ -14,6 +14,7 @@ const typeDefs = gql`
     question: String
     options: [Option]
     images: [Images]
+    examId: String
   }
   type Questions {
     count: Int