Optimistic locking option

src/main/kotlin/nl/astraeus/persistence/Logger.kt

@@ -1,8 +1,62 @@
 package nl.astraeus.nl.astraeus.persistence
 
+enum class LogLevel {
+  TRACE,
+  DEBUG,
+  INFO,
+  WARN,
+  ERROR
+}
+
 object Logger {
-  var debug: (String) -> Unit = { println("DEBUG: $it") }
-  var info: (String) -> Unit = { println("INFO: $it") }
-  var warn: (String) -> Unit = { println("WARN: $it") }
-  var error: (String) -> Unit = { println("ERROR: $it") }
-}
+  var level: LogLevel = LogLevel.DEBUG
+
+  var tracePrinter: (String) -> Unit = { println(it) }
+  var debugPrinter: (String) -> Unit = { println(it) }
+  var infoPrinter: (String) -> Unit = { println(it) }
+  var warnPrinter: (String) -> Unit = { println(it) }
+  var errorPrinter: (String) -> Unit = { System.err.println(it) }
+
+  fun trace(message: String, vararg parameters: Any?) {
+    if (level <= LogLevel.TRACE) {
+      writeLogMessage(LogLevel.TRACE, message, *parameters)
+    }
+  }
+
+  fun debug(message: String, vararg parameters: Any?) {
+    if (level <= LogLevel.DEBUG) {
+      writeLogMessage(LogLevel.DEBUG, message, *parameters)
+    }
+  }
+
+  fun info(message: String, vararg parameters: Any?) {
+    if (level <= LogLevel.INFO) {
+      writeLogMessage(LogLevel.INFO, message, *parameters)
+    }
+  }
+
+  fun warn(message: String, vararg parameters: Any?) {
+    if (level <= LogLevel.DEBUG) {
+      writeLogMessage(LogLevel.DEBUG, message, *parameters)
+    }
+  }
+
+  fun error(message: String, vararg parameters: Any?) {
+    if (level <= LogLevel.ERROR) {
+      writeLogMessage(LogLevel.ERROR, message, *parameters)
+    }
+  }
+
+  private fun writeLogMessage(level: LogLevel, message: String, vararg parameters: Any?) {
+    val formattedMessage = "[${level}] - ${message.format(*parameters)}"
+
+    when (level) {
+      LogLevel.TRACE -> tracePrinter(formattedMessage)
+      LogLevel.DEBUG -> debugPrinter(formattedMessage)
+      LogLevel.INFO -> infoPrinter(formattedMessage)
+      LogLevel.WARN -> warnPrinter(formattedMessage)
+      LogLevel.ERROR -> errorPrinter(formattedMessage)
+    }
+
+  }
+}