/*
    * Copyright 2009-2010 Steve Chaloner
    *
    * 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 be.objectify.led;
  
  import be.objectify.led.util.ContractUtils;
  import be.objectify.led.util.StringUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Properties;
  
  /**
   * Default implementation of {@link PropertyContext} which
   *
   * @author Steve Chaloner
   */
  public class DefaultPropertyContext implements PropertyContext
  {
      private static final Logger LOGGER = LoggerFactory.getLogger(DefaultPropertyContext.class);
  
      private final Properties properties = new Properties();
  
      public DefaultPropertyContext(Properties... properties)
      {
          ContractUtils.nonNull(properties, "properties");
  
          for (Properties propertiesInstance : properties)
          {
              this.properties.putAll(propertiesInstance);
          }
      }
  
      /** {@inheritDoc} */
      public String getValue(String propertyName)
      {
          String value = null;
  
          if (properties.containsKey(propertyName))
          {
              value = properties.getProperty(propertyName);
          }
  
          String property = System.getProperty(propertyName);
          if (!StringUtils.isEmpty(property))
          {
              value = property;
          }
  
          if (value != null)
          {
              LOGGER.debug("Found value [{}] for property [{}]",
                           value,
                           propertyName);
          }
  
          return value;
      }
  }