refactor: enhance logging functionalities

- Replace usage of static AppLogger class with separate logging functions
- Introduce individual logger functions for error, warning, info, and debug levels
- Create a default stand-alone logger instance to handle logging operations

Author: muzahidul-opti

lib/optimizely_flutter_sdk.dart

@@ -100,7 +100,7 @@ class OptimizelyFlutterSdk {
       if (logger != null) {
         setLogger(logger);
       } else {
-        AppLogger.warning("Logger not provided.");
+        logWarning("Logger not provided.");
       }
   }
 

lib/src/logger/flutter_logger.dart

@@ -8,35 +8,19 @@ abstract class OptimizelyLogger {
 class DefaultOptimizelyLogger implements OptimizelyLogger {
   @override
   void log(OptimizelyLogLevel level, String message) {
-    print('${level.name} $message');
+    print('[OPTIMIZELY] [${level.name.toUpperCase()}]: $message');
   }
 }
 
-class AppLogger {
-  static OptimizelyLogger _instance = DefaultOptimizelyLogger();
-
-  /// Get the current app logger instance
-  static OptimizelyLogger get instance => _instance;
-
-  /// Reset to default logger
-  static void reset() {
-    _instance = DefaultOptimizelyLogger();
-  }
-
-  /// Convenience methods for direct logging
-  static void error(String message) {
-    _instance.log(OptimizelyLogLevel.error, message);
-  }
-
-  static void warning(String message) {
-    _instance.log(OptimizelyLogLevel.warning, message);
-  }
-
-  static void info(String message) {
-    _instance.log(OptimizelyLogLevel.info, message);
-  }
-
-  static void debug(String message) {
-    _instance.log(OptimizelyLogLevel.debug, message);
-  }
-}
+/// App logger instance
+final _appLogger = DefaultOptimizelyLogger();
+
+/// App logging functions
+void logError(String message) =>
+    _appLogger.log(OptimizelyLogLevel.error, message);
+void logWarning(String message) =>
+    _appLogger.log(OptimizelyLogLevel.warning, message);
+void logInfo(String message) =>
+    _appLogger.log(OptimizelyLogLevel.info, message);
+void logDebug(String message) =>
+    _appLogger.log(OptimizelyLogLevel.debug, message);

lib/src/logger/logger_bridge.dart

@@ -10,24 +10,24 @@ class LoggerBridge {
 
   /// Initialize the logger bridge to receive calls from native
   static void initialize(OptimizelyLogger? logger) {
-    AppLogger.info('[LoggerBridge] Initializing with logger: ${logger != null}');
+    logInfo('[LoggerBridge] Initializing with logger: ${logger != null}');
     _customLogger = logger;
     _loggerChannel.setMethodCallHandler(_handleMethodCall);
   }
 
   /// Handle incoming method calls from native Swift/Java code
   static Future<void> _handleMethodCall(MethodCall call) async {
-    AppLogger.info('[LoggerBridge] Received method call: ${call.method}');
+    logInfo('[LoggerBridge] Received method call: ${call.method}');
     try {
       switch (call.method) {
         case 'log':
           await _handleLogCall(call);
           break;
         default:
-          AppLogger.warning('[LoggerBridge] Unknown method call: ${call.method}');
+          logWarning('[LoggerBridge] Unknown method call: ${call.method}');
       }
     } catch (e) {
-      AppLogger.error('[LoggerBridge] Error handling method call: $e');
+      logError('[LoggerBridge] Error handling method call: $e');
     }
   }
 
@@ -40,21 +40,21 @@ class LoggerBridge {
       final message = args['message'] as String?;
 
       if (levelRawValue == null || message == null) {
-        AppLogger.error('[LoggerBridge] Warning: Missing level or message in log call');
+        logError('[LoggerBridge] Warning: Missing level or message in log call');
         return;
       }
 
       final level = _convertLogLevel(levelRawValue);
 
-      AppLogger.info('[LoggerBridge] Processing log: level=$levelRawValue, message=$message');
+      logInfo('[LoggerBridge] Processing log: level=$levelRawValue, message=$message');
 
       if (_customLogger != null) {
         _customLogger!.log(level, message);
       } else {
-        AppLogger.info('[Optimizely ${level.name}] $message');
+        logInfo('[Optimizely ${level.name}] $message');
       }
     } catch (e) {
-      AppLogger.error('[LoggerBridge] Error processing log call: $e');
+      logError('[LoggerBridge] Error processing log call: $e');
     }
   }