chore: Unify backend express project into ESM (#281)

entrypoint.js

@@ -0,0 +1,89 @@
+import { createServer as createHttpServer } from 'http';
+import path from 'path';
+import fs from 'fs';
+import { execSync } from 'child_process';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+// Use express from backend node_modules
+import expressModule from './backend/node_modules/express/index.js';
+const express = expressModule.default || expressModule;
+
+async function runMigrations() {
+  try {
+    console.log('Running database migrations...');
+    // Use execSync with cwd option to run in the backend directory
+    execSync('npx sequelize-cli db:migrate', {
+      cwd: path.join(__dirname, 'backend'),
+      stdio: 'inherit',
+    });
+    console.log('Database migrations completed successfully.');
+    if (process.env.IS_DEMO === 'true' || process.env.IS_DEMO === '1') {
+      console.log('Demo mode detected. Seeding the database...');
+      execSync('npx sequelize-cli db:seed:all', {
+        cwd: path.join(__dirname, 'backend'),
+        stdio: 'inherit',
+      });
+      console.log('Database seeding completed successfully.');
+    }
+  } catch (error) {
+    console.error('Error running database migrations or seeding:', error);
+    throw error;
+  }
+}
+
+async function startServer() {
+  try {
+    const server = express();
+    const httpServer = createHttpServer(server);
+
+    // Import the backend app
+    const backendAppModule = await import('./backend/server.js');
+    const backendApp = backendAppModule.default || backendAppModule;
+    server.use('/api', backendApp);
+
+    // For Next.js standalone build
+    // Check if we have the Next.js server file
+    const nextServerPath = './node_modules/next/dist/server/next.js';
+    if (fs.existsSync(nextServerPath)) {
+      // Import Next.js
+      const nextModule = await import(nextServerPath);
+      const next = nextModule.default || nextModule;
+
+      // Initialize Next.js app
+      const dev = process.env.NODE_ENV !== 'production';
+      const nextApp = next({ dev, dir: path.join(__dirname, '.') });
+      const handle = nextApp.getRequestHandler();
+      await nextApp.prepare();
+      console.log('nextjs prepared');
+
+      // Use Next.js to handle all other routes
+      server.all('*', (req, res) => handle(req, res));
+    } else {
+      console.error('Next.js module not found at:', nextServerPath);
+      server.all('*', (req, res) => {
+        res.status(500).send('Frontend server not available');
+      });
+    }
+
+    const PORT = process.env.PORT || 8000;
+    httpServer.listen(PORT, (err) => {
+      if (err) throw err;
+      console.log(`> Ready on http://localhost:${PORT}`);
+    });
+  } catch (error) {
+    console.error('Error starting server:', error);
+    process.exit(1);
+  }
+}
+
+runMigrations()
+  .then(() => {
+    startServer();
+  })
+  .catch((error) => {
+    console.error('Failed to start application:', error);
+    process.exit(1);
+  });