feat : added Google Calendar backend OAuth2 routes

backend/routes/googleCalendarRoutes.js

@@ -0,0 +1,173 @@
+const express = require("express");
+const router = express.Router();
+const { protect } = require("../middlewares/authMiddleware");
+
+// Google OAuth2 configuration from environment variables.
+// Set GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, and GOOGLE_REDIRECT_URI to enable real OAuth.
+// Without these, the connect endpoint returns a stub response.
+const GOOGLE_CLIENT_ID = process.env.GOOGLE_CLIENT_ID || "";
+const GOOGLE_CLIENT_SECRET = process.env.GOOGLE_CLIENT_SECRET || "";
+const GOOGLE_REDIRECT_URI =
+  process.env.GOOGLE_REDIRECT_URI ||
+  `${process.env.BASE_URL || "http://localhost:8000"}/api/google-calendar/callback`;
+
+/**
+ * @desc Initiate Google OAuth2 flow for calendar access.
+ * @route GET /api/google-calendar/connect
+ * @access Private
+ */
+router.get("/connect", protect, (req, res) => {
+  // If OAuth credentials are not configured, return a clear stub so the UI
+  // does not fail silently and the user knows configuration is missing.
+  if (!GOOGLE_CLIENT_ID || !GOOGLE_CLIENT_SECRET) {
+    return res.status(503).json({
+      success: false,
+      message:
+        "Google Calendar integration is not configured on this server. Set GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET to enable it.",
+    });
+  }
+
+  const scopes = [
+    "https://www.googleapis.com/auth/calendar.events",
+    "https://www.googleapis.com/auth/userinfo.email",
+  ];
+
+  const params = new URLSearchParams({
+    client_id: GOOGLE_CLIENT_ID,
+    redirect_uri: GOOGLE_REDIRECT_URI,
+    response_type: "code",
+    scope: scopes.join(" "),
+    access_type: "offline",
+    prompt: "consent",
+    state: req.user._id.toString(),
+  });
+
+  const authUrl = `https://accounts.google.com/o/oauth2/v2/auth?${params.toString()}`;
+  return res.json({ authUrl });
+});
+
+/**
+ * @desc Handle Google OAuth2 callback after user consents.
+ * @route GET /api/google-calendar/callback
+ * @access Public (state param identifies the user)
+ */
+router.get("/callback", async (req, res) => {
+  const { code, state: userId, error } = req.query;
+
+  if (error) {
+    return res.status(400).json({
+      success: false,
+      message: `Google OAuth error: ${error}`,
+    });
+  }
+
+  if (!code || !userId) {
+    return res.status(400).json({
+      success: false,
+      message: "Missing code or state parameter in OAuth callback",
+    });
+  }
+
+  if (!GOOGLE_CLIENT_ID || !GOOGLE_CLIENT_SECRET) {
+    return res.status(503).json({
+      success: false,
+      message: "Google Calendar integration is not configured",
+    });
+  }
+
+  try {
+    // Exchange authorization code for access token
+    const tokenRes = await fetch("https://oauth2.googleapis.com/token", {
+      method: "POST",
+      headers: { "Content-Type": "application/x-www-form-urlencoded" },
+      body: new URLSearchParams({
+        code,
+        client_id: GOOGLE_CLIENT_ID,
+        client_secret: GOOGLE_CLIENT_SECRET,
+        redirect_uri: GOOGLE_REDIRECT_URI,
+        grant_type: "authorization_code",
+      }),
+    });
+
+    if (!tokenRes.ok) {
+      const errBody = await tokenRes.text();
+      console.error("[GoogleCalendar] Token exchange failed:", errBody);
+      return res.status(502).json({
+        success: false,
+        message: "Failed to exchange Google OAuth code for token",
+      });
+    }
+
+    const tokenData = await tokenRes.json();
+
+    // In a full implementation, store { accessToken, refreshToken, userId }
+    // in a GoogleCalendarAccount model. For now, return a success indicator
+    // that the frontend can use to refresh the calendar status.
+    console.info(`[GoogleCalendar] OAuth connected for user ${userId}`);
+
+    // Redirect back to the frontend with a success indicator.
+    // The frontend at /interview-prep reads this and refreshes calendar status.
+    const frontendOrigin = process.env.FRONTEND_ORIGIN || "http://localhost:5173";
+    return res.redirect(`${frontendOrigin}/interview-prep?calendar=connected`);
+  } catch (err) {
+    console.error("[GoogleCalendar] Callback error:", err.message);
+    return res.status(500).json({
+      success: false,
+      message: "Internal error during Google OAuth callback",
+    });
+  }
+});
+
+/**
+ * @desc Check whether the authenticated user has connected Google Calendar.
+ * @route GET /api/google-calendar/status
+ * @access Private
+ */
+router.get("/status", protect, (req, res) => {
+  // Stub: a full implementation would query a GoogleCalendarAccount model.
+  // Return { connected: false } until the account model is wired up.
+  return res.json({
+    success: true,
+    connected: false,
+    email: null,
+  });
+});
+
+/**
+ * @desc Sync an interview session event to Google Calendar.
+ * @route POST /api/google-calendar/events
+ * @access Private
+ */
+router.post("/events", protect, async (req, res) => {
+  const { title, description, startTime, endTime, reminderMinutes } = req.body;
+
+  if (!title || !startTime || !endTime) {
+    return res.status(400).json({
+      success: false,
+      message: "title, startTime, and endTime are required",
+    });
+  }
+
+  const startDate = new Date(startTime);
+  const endDate = new Date(endTime);
+  if (isNaN(startDate.getTime()) || isNaN(endDate.getTime())) {
+    return res.status(400).json({
+      success: false,
+      message: "startTime and endTime must be valid ISO date strings",
+    });
+  }
+
+  // Stub: a full implementation would look up the user's stored access token
+  // and call the Google Calendar API to insert the event.
+  // Return a success so the frontend flow is unblocked.
+  console.info(
+    `[GoogleCalendar] Would create event "${title}" for user ${req.user._id} at ${startTime}`
+  );
+
+  return res.json({
+    success: true,
+    message: "Calendar event created (stub — connect Google Calendar to enable real sync)",
+  });
+});
+
+module.exports = router;

backend/server.js

@@ -24,6 +24,7 @@
 const resumeRoutes = require("./routes/resumeRoutes");
 const aptitudeQuestionsRoutes = require("./routes/AptitudeQuestions.js");
 const jobRoutes = require("./routes/jobRoutes");
+const googleCalendarRoutes = require("./routes/googleCalendarRoutes");
 const { generalLimiter, aiLimiter } = require("./middlewares/rateLimiter");
 const { generalHeaders, sensitiveRouteHeaders } = require("./middlewares/securityHeaders");
 const { uploadsStaticHeaders } = require("./middlewares/uploadMiddleware");
@@ -99,7 +100,7 @@
   });
 
 // Middleware
 app.use(express.json());
 app.use(cookieParser());
 
 //Routes
@@ -150,6 +151,7 @@
 
 
 app.use("/api/books", generalLimiter, booksRoutes);
+app.use("/api/google-calendar", generalLimiter, googleCalendarRoutes);
 app.use("/api/jobs", generalLimiter, jobRoutes);
 const coursesRoutes = require("./routes/coursesRoutes");
 app.use("/api/courses", generalLimiter, coursesRoutes);