Add Alias Functionality

.gitignore

@@ -1,3 +1,3 @@
-.node_modules/
+/node_modules
 .env
 .idea/

server.js

@@ -14,16 +14,62 @@ app.use(cors());
 app.use(express.json());
 
 // PostgreSQL connection pool
-const pool = new Pool({
-    host: process.env.DB_HOST,
-    port: process.env.DB_PORT,
-    database: process.env.DB_DATABASE,
-    user: process.env.DB_USER,
-    password: process.env.DB_PASSWORD,
-    max: 20,
-    idleTimeoutMillis: 30000,
-    connectionTimeoutMillis: 2000,
-});
+function handleHeaders(headers) {
+
+    const alias = (headers['db-alias'] || 'default').toUpperCase().replace(/-/g, '_');
+
+    let pool={
+        host:     process.env[`DB_${alias}_HOST`],     
+        port:     process.env[`DB_${alias}_PORT`],     
+        database: process.env[`DB_${alias}_DATABASE`], 
+        user:     process.env[`DB_${alias}_USER`],     
+        password: process.env[`DB_${alias}_PASSWORD`], 
+        max: 20,
+        idleTimeoutMillis: 30000,
+        connectionTimeoutMillis: 2000,
+    };
+
+    const allUndefined = pool.host=== undefined && pool.port=== undefined && pool.database=== undefined && pool.user=== undefined && pool.password=== undefined;
+    const someUndefined = pool.host=== '' || pool.port=== '' || pool.database=== '' || pool.user=== '' || pool.password=== '';
+    const someDefined   = pool.host != undefined || pool.port != undefined || pool.database != undefined || pool.user != undefined || pool.password != undefined;
+
+    if (allUndefined) {
+        throw new Error('Invalid db alias');
+    }
+    else if(someUndefined && someDefined) { 
+        console.log(pool);
+        if(pool.host  === '') {
+            throw new Error('Host is not configured for the specified db alias');
+        }
+        if(pool.port  === '') {
+            throw new Error('Port is not configured for the specified db alias');
+        }
+        if(pool.database === '') {
+            throw new Error('Database is not configured for the specified db alias');
+        }
+        if(pool.user === '') {
+            throw new Error('User is not configured for the specified db alias');
+        }
+        if(pool.password === '') {
+            throw new Error('Password is not configured for the specified db alias');
+        }
+        
+    }
+    else{
+          return new Pool({
+        host:     process.env[`DB_${alias}_HOST`],     
+        port:     process.env[`DB_${alias}_PORT`],     
+        database: process.env[`DB_${alias}_DATABASE`], 
+        user:     process.env[`DB_${alias}_USER`],     
+        password: process.env[`DB_${alias}_PASSWORD`], 
+        max: 20,
+        idleTimeoutMillis: 30000,
+        connectionTimeoutMillis: 2000,
+        });
+    }
+     
+    
+}
 
 // Health check endpoint
 app.get('/api/health', (req, res) => {
@@ -45,7 +91,9 @@ app.post('/api/postgres/select', async (req, res) => {
         });
     }
 
+    let pool;
     try {
+        pool = handleHeaders(req.headers);
         const result = await pool.query(query, bindings);
 
         res.json({
@@ -55,10 +103,12 @@ app.post('/api/postgres/select', async (req, res) => {
         });
     } catch (error) {
         console.error('SELECT Error:', error);
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
+    } finally {
+        if (pool) await pool.end();
     }
 });
 
@@ -73,7 +123,9 @@ app.post('/api/postgres/execute', async (req, res) => {
         });
     }
 
+    let pool;
     try {
+        pool = handleHeaders(req.headers);
         const result = await pool.query(query, bindings);
 
         res.json({
@@ -82,10 +134,12 @@ app.post('/api/postgres/execute', async (req, res) => {
         });
     } catch (error) {
         console.error('EXECUTE Error:', error);
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
+    } finally {
+        if (pool) await pool.end();
     }
 });
 
@@ -100,9 +154,11 @@ app.post('/api/postgres/transaction', async (req, res) => {
         });
     }
 
+    let pool;
     const client = await pool.connect();
 
     try {
+        pool = handleHeaders(req.headers);
         await client.query('BEGIN');
 
         const results = [];
@@ -124,12 +180,13 @@ app.post('/api/postgres/transaction', async (req, res) => {
         await client.query('ROLLBACK');
         console.error('TRANSACTION Error:', error);
 
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
     } finally {
         client.release();
+        if (pool) await pool.end();
     }
 });
 
@@ -144,7 +201,9 @@ app.post('/api/postgres/insert', async (req, res) => {
         });
     }
 
+    let pool;
     try {
+        pool = handleHeaders(req.headers);
         const columns = Object.keys(data);
         const values = Object.values(data);
         const placeholders = values.map((_, i) => `$${i + 1}`).join(', ');
@@ -163,10 +222,12 @@ app.post('/api/postgres/insert', async (req, res) => {
         });
     } catch (error) {
         console.error('INSERT Error:', error);
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
+    } finally {
+        if (pool) await pool.end();
     }
 });
 
@@ -181,7 +242,9 @@ app.post('/api/postgres/update', async (req, res) => {
         });
     }
 
+    let pool;
     try {
+        pool = handleHeaders(req.headers);
         const setColumns = Object.keys(data);
         const setValues = Object.values(data);
         const whereColumns = Object.keys(where);
@@ -209,10 +272,12 @@ app.post('/api/postgres/update', async (req, res) => {
         });
     } catch (error) {
         console.error('UPDATE Error:', error);
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
+    } finally {
+        if (pool) await pool.end();
     }
 });
 
@@ -227,7 +292,9 @@ app.post('/api/postgres/delete', async (req, res) => {
         });
     }
 
+    let pool;
     try {
+        pool = handleHeaders(req.headers);
         const whereColumns = Object.keys(where);
         const whereValues = Object.values(where);
 
@@ -245,10 +312,12 @@ app.post('/api/postgres/delete', async (req, res) => {
         });
     } catch (error) {
         console.error('DELETE Error:', error);
-        res.status(500).json({
+        res.status(400).json({
             success: false,
             error: error.message
         });
+    } finally {
+        if (pool) await pool.end();
     }
 });
 
@@ -261,6 +330,5 @@ app.listen(PORT, () => {
 // Handle shutdown gracefully
 process.on('SIGINT', async () => {
     console.log('\nShutting down gracefully...');
-    await pool.end();
     process.exit(0);
 });