refactor: Clean up logging system with LOG_LEVEL filtering

- Add LOG_LEVEL env variable support (debug, info, warn, error)
- Default to 'info' level for production-ready logs
- Integrate Morgan HTTP logging with custom logger
- Remove console.logs and replace with custom logger
- Remove sensitive password debug logs from email service
- Remove noisy warn logs from email sync and event notifier
- Add gray color for timestamps to improve readability

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app.js

@@ -10,6 +10,7 @@ import { validateBody } from './middlewares/global/validateBody.js';
 import { notFound } from './middlewares/global/notFound.js';
 import { errorHandler } from './middlewares/global/errorHandler.js';
 import { apiRateLimiter } from './middlewares/security/rateLimiter.js';
+import { logger } from './utils/logger.js';
 
 // Import routes
 import authRoutes from './routes/auth.routes.js';
@@ -29,8 +30,9 @@ import eventRoutes from './routes/event.routes.js';
 
 const app = express();
 
-// Security middleware
+// HTTP request logging via Morgan -> custom logger
-app.use(morgan('dev'));
+const morganStream = { write: (message) => logger.http(message.trim()) };
+app.use(morgan(':method :url :status :response-time ms', { stream: morganStream }));
 app.use(
   helmet({
     contentSecurityPolicy: {

src/config/database.js

@@ -15,9 +15,9 @@ const pool = new Pool({
   connectionTimeoutMillis: 2000,
 });
 
-// Note: Connection logging handled in index.js to avoid circular dependencies
+// Critical database errors - use console.error directly to avoid circular imports
 pool.on('error', (err) => {
-  console.error('Neočakávaná chyba databázy:', err);
+  console.error('[FATAL] Database connection error:', err.message);
   process.exit(-1);
 });
 

src/cron/calendar/event-notifier.js

@@ -332,7 +332,6 @@ export const sendSingleEventNotification = async (eventId, adminUserId) => {
     const userEmail = await getUserEmail(userId);
 
     if (!userEmail) {
-      logger.warn(`Používateľ ${username} nemá nastavený primárny email - preskakujem`);
       stats.skipped++;
       continue;
     }
@@ -343,7 +342,7 @@ export const sendSingleEventNotification = async (eventId, adminUserId) => {
     const textBody = generateEventNotificationText({ firstName, username, event });
 
     // Send email
-    logger.info(`Odosielam notifikáciu pre ${username} (${userEmail})`);
+    logger.info(`Odosielam notifikáciu pre ${username}`);
 
     const success = await sendNotificationEmail(jmapConfig, userEmail, subject, htmlBody, textBody);
 
@@ -427,7 +426,6 @@ export const sendEventNotifications = async () => {
     const userEmail = await getUserEmail(userId);
 
     if (!userEmail) {
-      logger.warn(`Používateľ ${username} nemá nastavený primárny email - preskakujem`);
       stats.skipped++;
       continue;
     }
@@ -438,7 +436,7 @@ export const sendEventNotifications = async () => {
     const textBody = generateEventNotificationText({ firstName, username, event });
 
     // Send email
-    logger.info(`Odosielam notifikáciu pre ${username} (${userEmail}) - udalosť: ${event.title}`);
+    logger.info(`Odosielam notifikáciu pre ${username} - udalosť: ${event.title}`);
 
     const success = await sendNotificationEmail(jmapConfig, userEmail, subject, htmlBody, textBody);
 

src/index.js

@@ -1,9 +1,10 @@
 import app from './app.js';
 import { startAllCronJobs } from './cron/index.js';
+import { logger } from './utils/logger.js';
 
 const port = process.env.PORT || 5000;
 app.listen(port, () => {
-  console.log(`🚀 Server running on http://localhost:${port}`);
+  logger.info(`Server running on http://localhost:${port}`);
 
   // Start cron jobs after server is running
   startAllCronJobs();

src/middlewares/auth/resourceAccessMiddleware.js

@@ -1,6 +1,7 @@
 import { db } from '../../config/database.js';
 import { companyUsers, projectUsers, todoUsers } from '../../db/schema.js';
 import { eq, and } from 'drizzle-orm';
+import { logger } from '../../utils/logger.js';
 
 /**
  * Univerzálny middleware pre kontrolu prístupu k resources
@@ -104,7 +105,7 @@ export const checkResourceAccess = (resourceType, paramName) => {
 
       next();
     } catch (error) {
-      console.error('Resource access check error:', error);
+      logger.error('Resource access check error', error);
       return res.status(500).json({
         success: false,
         error: {

src/services/email-account.service.js

@@ -409,19 +409,8 @@ export const removeUserFromEmailAccount = async (accountId, userId) => {
  * Get email account with decrypted password (for JMAP operations)
  */
 export const getEmailAccountWithCredentials = async (accountId, userId) => {
-  logger.debug('getEmailAccountWithCredentials called', { accountId, userId });
-
   const account = await getEmailAccountById(accountId, userId);
-
-  logger.debug('Account retrieved', {
-    id: account.id,
-    email: account.email,
-    hasPassword: !!account.emailPassword,
-    passwordLength: account.emailPassword?.length
-  });
-
   const decryptedPassword = decryptPassword(account.emailPassword);
-  logger.debug('Password decrypted', { passwordLength: decryptedPassword?.length });
 
   return {
     id: account.id,

src/services/jmap/sync.js

@@ -147,7 +147,6 @@ export const syncEmailsFromSender = async (
 
         // Skip emails without from or to (malformed data)
         if (!fromEmail && !toEmail) {
-          logger.warn(`Preskakujem email ${messageId} - chýba pole from aj to`);
           continue;
         }
 
@@ -160,7 +159,6 @@ export const syncEmailsFromSender = async (
           toEmail?.toLowerCase() === senderEmail.toLowerCase();
 
         if (!belongsToContact) {
-          logger.warn(`Preskakujem email ${messageId} - nepatrí kontaktu ${senderEmail} (od: ${fromEmail}, pre: ${toEmail})`);
           continue;
         }
 

src/services/timesheet.service.js

@@ -4,6 +4,7 @@ import { db } from '../config/database.js';
 import { timesheets, users } from '../db/schema.js';
 import { and, desc, eq } from 'drizzle-orm';
 import { BadRequestError, ForbiddenError, NotFoundError } from '../utils/errors.js';
+import { logger } from '../utils/logger.js';
 
 const ALLOWED_MIME_TYPES = [
   'application/pdf',
@@ -71,8 +72,7 @@ const safeUnlink = async (filePath) => {
   try {
     await fs.unlink(filePath);
   } catch (error) {
-    // Keep server responsive even if cleanup fails
+    logger.error('Failed to delete file', error);
-    console.error('Nepodarilo sa zmazať súbor:', error);
   }
 };
 

src/services/todo.service.js

@@ -142,7 +142,6 @@ export const getTodoById = async (todoId) => {
  */
 export const createTodo = async (userId, data) => {
   const { title, description, projectId, companyId, assignedUserIds, status, priority, dueDate } = data;
-  console.log('Service createTodo - assignedUserIds:', assignedUserIds);
 
   // Verify project exists if provided
   if (projectId) {
@@ -205,10 +204,7 @@ export const createTodo = async (userId, data) => {
       assignedBy: userId,
     }));
 
-    console.log('Inserting todo_users:', todoUserInserts);
     await db.insert(todoUsers).values(todoUserInserts);
-  } else {
-    console.log('No users to assign - assignedUserIds:', assignedUserIds);
   }
 
   return newTodo;

src/utils/logger.js

@@ -1,7 +1,22 @@
 /**
- * Simple logger utility
+ * Logger utility with LOG_LEVEL filtering
+ *
+ * LOG_LEVEL options (from lowest to highest):
+ * - debug: Show all logs
+ * - info: Show info, success, warn, error, audit
+ * - warn: Show warn, error, audit
+ * - error: Show only errors and audit
+ *
+ * Default: 'info' (production-ready default)
  */
 
+const LOG_LEVELS = {
+  debug: 0,
+  info: 1,
+  warn: 2,
+  error: 3,
+};
+
 const colors = {
   reset: '\x1b[0m',
   red: '\x1b[31m',
@@ -10,37 +25,51 @@ const colors = {
   blue: '\x1b[34m',
   magenta: '\x1b[35m',
   cyan: '\x1b[36m',
+  gray: '\x1b[90m',
 };
 
 const getTimestamp = () => {
   return new Date().toISOString();
 };
 
+const getCurrentLevel = () => {
+  const level = process.env.LOG_LEVEL?.toLowerCase() || 'info';
+  return LOG_LEVELS[level] ?? LOG_LEVELS.info;
+};
+
+const shouldLog = (level) => {
+  return LOG_LEVELS[level] <= getCurrentLevel();
+};
+
 export const logger = {
   info: (message, ...args) => {
+    if (!shouldLog('info')) return;
     console.log(
-      `${colors.blue}[INFO]${colors.reset} ${getTimestamp()} - ${message}`,
+      `${colors.blue}[INFO]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
       ...args
     );
   },
 
   success: (message, ...args) => {
+    if (!shouldLog('info')) return;
     console.log(
-      `${colors.green}[SUCCESS]${colors.reset} ${getTimestamp()} - ${message}`,
+      `${colors.green}[SUCCESS]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
       ...args
     );
   },
 
   warn: (message, ...args) => {
+    if (!shouldLog('warn')) return;
     console.warn(
-      `${colors.yellow}[WARN]${colors.reset} ${getTimestamp()} - ${message}`,
+      `${colors.yellow}[WARN]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
       ...args
     );
   },
 
   error: (message, error, ...args) => {
+    if (!shouldLog('error')) return;
     console.error(
-      `${colors.red}[ERROR]${colors.reset} ${getTimestamp()} - ${message}`,
+      `${colors.red}[ERROR]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
       ...args
     );
     if (error && process.env.NODE_ENV === 'development') {
@@ -49,18 +78,26 @@ export const logger = {
   },
 
   debug: (message, ...args) => {
-    if (process.env.NODE_ENV === 'development') {
+    if (!shouldLog('debug')) return;
-      console.log(
-        `${colors.cyan}[DEBUG]${colors.reset} ${getTimestamp()} - ${message}`,
-        ...args
-      );
-    }
-  },
-
-  audit: (message, ...args) => {
     console.log(
-      `${colors.magenta}[AUDIT]${colors.reset} ${getTimestamp()} - ${message}`,
+      `${colors.cyan}[DEBUG]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
       ...args
     );
   },
+
+  audit: (message, ...args) => {
+    // Audit logs always show regardless of level
+    console.log(
+      `${colors.magenta}[AUDIT]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`,
+      ...args
+    );
+  },
+
+  // HTTP request logger (for Morgan integration)
+  http: (message) => {
+    if (!shouldLog('info')) return;
+    console.log(
+      `${colors.gray}[HTTP]${colors.reset} ${colors.gray}${getTimestamp()}${colors.reset} ${message}`
+    );
+  },
 };