content: /*
   * Copyright 2014 Adam Bien.
   *
   * 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.airhacks.afterburner.configuration;
  
  /*
   * #%L
   * afterburner.fx
   * %%
   * Copyright (C) 2013 - 2014 Adam Bien
   * %%
   * 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.
   * #L%
   */
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Properties;
  import java.util.function.Consumer;
  import java.util.function.Function;
  
  /**
   *
   * @author airhacks.com
   */
  public class Configurator {
  
      public final static String CONFIGURATION_FILE = "configuration.properties";
  
      private final Properties systemProperties;
      private Function<Object, Object> customConfigurator;
  
      private Consumer<String> LOG;
  
      public Configurator() {
          this.systemProperties = System.getProperties();
          this.LOG = l -> {
          };
      }
  
      public Configurator set(Function<Object, Object> custom) {
          this.customConfigurator = custom;
          return this;
      }
  
      public Configurator setLogger(Consumer<String> log) {
          this.LOG = log;
          return this;
      }
  
      Properties getProperties(Class<?> clazz) {
          Properties configuration = new Properties();
          try (InputStream stream = clazz.getResourceAsStream(CONFIGURATION_FILE)) {
              if (stream == null) {
                  return null;
              }
              configuration.load(stream);
          } catch (IOException ex) {
              //a property file does not have to exist...
          }
          return configuration;
      }
  
      /**
       *
       * @param clazz is used to locate the properties @see
       * java.lang.Class#getResourceAsStream
       * @param key to be resolved
       * @return the resolved value.
       */
      public Object getProperty(Class<?> clazz, Object key) {
          Object value = this.systemProperties.get(key);
          if (value != null) {
              return value;
          }
          if (customConfigurator != null) {
              value = customConfigurator.apply(key);
              if (value != null) {
                  return value;
              }
          }
          Properties clazzProperties = this.getProperties(clazz);
          if (clazzProperties != null) {
              value = clazzProperties.get(key);
          }
          return value;
      }
  
      public void forgetAll() {
          this.customConfigurator = null;
      }
  
  }
  