server implementation for poster generation

server/movie_posters/lib/index.js

@@ -0,0 +1,82 @@
+import { poster } from './poster.js';
+import { start as startProfiler } from '@google-cloud/profiler'; // Renamed import for clarity
+import cors from 'cors';
+import express from 'express';
+
+// --- Configuration ---
+const PORT = process.env.PORT || 3000;
+// Enable profiler, e.g., only in production environments
+const PROFILER_ENABLED = process.env.ENABLE_PROFILER === 'true' || process.env.NODE_ENV === 'production';
+const SERVICE_NAME = 'movie_posters';
+const SERVICE_VERSION = '1.0.0'; // Consider reading from package.json
+
+// --- Application Setup ---
+const app = express();
+
+// --- Google Cloud Profiler Setup ---
+if (PROFILER_ENABLED) {
+    startProfiler({
+        projectId: process.env.PROJECT_ID, // Ensure PROJECT_ID is set in the environment
+        serviceContext: {
+            service: SERVICE_NAME,
+            version: SERVICE_VERSION,
+        },
+    }).then(() => {
+        console.log(`Google Cloud Profiler started for service ${SERVICE_NAME} v${SERVICE_VERSION}.`);
+    }).catch(err => {
+        // Log the error but don't prevent the app from starting
+        console.error('Failed to start Google Cloud Profiler:', err);
+    });
+} else {
+    console.log('Google Cloud Profiler is disabled.');
+}
+
+// --- Core Middleware ---
+app.use(cors()); // Enable Cross-Origin Resource Sharing for all origins
+app.use(express.json()); // Parse incoming JSON request bodies
+
+// --- Specific Error Handling Middleware ---
+// Handles JSON parsing errors specifically, providing a clearer error message.
+app.use((err, req, res, next) => {
+    // Check if the error is a syntax error thrown by express.json()
+    if (err instanceof SyntaxError && err.status === 400 && 'body' in err) {
+        console.error('Bad JSON format received:', err.message);
+        return res.status(400).send({ error: 'Invalid JSON format in request body.' });
+    }
+    // Pass other errors down the middleware chain
+    next(err);
+});
+
+app.use('/poster', poster.router);
+
+// --- Routes ---
+
+// Root GET endpoint: Provides basic API status information.
+app.get("/", (req, res) => {
+    res.status(200).send({
+        status: 'API is running.',
+        message: 'Use the POST /poster endpoint with a JSON body to generate posters.',
+        service: SERVICE_NAME,
+        version: SERVICE_VERSION
+    });
+});
+
+// --- Generic Error Handler ---
+// Catches any errors passed via `next(err)` from preceding middleware or routes.
+// This should be the last middleware added.
+app.use((err, req, res, next) => {
+    console.error("Unhandled application error:", err);
+    // Ensure response is sent only once
+    if (!res.headersSent) {
+        res.status(500).send({ error: 'An internal server error occurred.' });
+    }
+});
+
+// --- Server Start ---
+app.listen(PORT, () => {
+    console.log(`Server listening on port ${PORT}`);
+    console.log(`Access the API at http://localhost:${PORT}`);
+    if (PROFILER_ENABLED) {
+        console.log(`Google Cloud Profiler is active for project: ${process.env.PROJECT_ID || 'Not Specified'}`);
+    }
+});