content: /*************************** The CRY.ME project (2023) *************************************************
   *
   *  This file is part of the CRY.ME project (https://github.com/ANSSI-FR/cry-me).
   *  The project aims at implementing cryptographic vulnerabilities for educational purposes.
   *  Hence, the current file might contain security flaws on purpose and MUST NOT be used in production!
   *  Please do not use this source code outside this scope, or use it knowingly.
   *
   *  Many files come from the Android element (https://github.com/vector-im/element-android), the
   *  Matrix SDK (https://github.com/matrix-org/matrix-android-sdk2) as well as the Android Yubikit
   *  (https://github.com/Yubico/yubikit-android) projects and have been willingly modified
   *  for the CRY.ME project purposes. The Android element, Matrix SDK and Yubikit projects are distributed
   *  under the Apache-2.0 license, and so is the CRY.ME project.
   *
   ***************************  (END OF CRY.ME HEADER)   *************************************************/
  
  /*
   * Copyright (C) 2019 Yubico.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *       http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.yubico.yubikit.core;
  
  
  import javax.annotation.Nullable;
  
  /**
   * Helper class allows to customize logs within the SDK
   * SDK has only 2 levels of logging: debug information and error
   * If a Logger implementation is not provided the SDK won't produce any logs
   */
  public abstract class Logger {
      /**
       * Specifies how debug messages are logged.
       * <p>
       * If this method is not overridden, then debug messages will not be logged.
       *
       * @param message the message can to be logged
       */
      protected void logDebug(String message) {
      }
  
      /**
       * Specifies how error messages (with exceptions) are logged.
       * <p>
       * If this method is not overridden, then error messages will not be logged.
       *
       * @param message   the message can to be logged
       * @param throwable the exception that can to be logged or counted
       */
      protected void logError(String message, Throwable throwable) {
      }
  
      @Nullable
      private static Logger instance = null;
  
      /**
       * Set the Logger implementation to use. Override the logDebug and logError methods to produce
       * logs. Call with null to disable logging.
       *
       * @param logger the Logger implementation to use
       */
      public static void setLogger(@Nullable Logger logger) {
          instance = logger;
      }
  
      /**
       * Log a debug message.
       */
      public static void d(String message) {
          if (instance != null) {
              instance.logDebug(message);
          }
      }
  
      /**
       * Log an error message, together with an exception.
       */
      public static void e(String message, Throwable throwable) {
          if (instance != null) {
              instance.logError(message, throwable);
          }
      }
  }
  