/**
    * Copyright 2010-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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 org.kuali.common.util.service;
  
  import java.util.List;
  import java.util.Properties;
  
  import org.kuali.common.util.LocationUtils;
  import org.kuali.common.util.ModeUtils;
  import org.kuali.common.util.PropertyUtils;
  import org.kuali.common.util.property.Constants;
  import org.kuali.common.util.property.PropertyLoadContext;
  import org.kuali.common.util.property.PropertyStoreContext;
  import org.kuali.common.util.property.processor.PropertyProcessor;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.util.PropertyPlaceholderHelper;
  
  public class DefaultPropertyService implements PropertyService {
  
  	private static final Logger logger = LoggerFactory.getLogger(DefaultPropertyService.class);
  
  	@Override
  	public Properties load(PropertyLoadContext context) {
  		Properties properties = loadProperties(context);
  		context.initialize(properties);
  		process(properties, context.getProcessors());
  		return properties;
  	}
  
  	@Override
  	public void store(PropertyStoreContext context, Properties properties) {
  		Properties duplicate = PropertyUtils.duplicate(properties);
  		context.initialize(duplicate);
  		process(duplicate, context.getProcessors());
  		PropertyUtils.store(duplicate, context.getFile(), context.getEncoding(), context.getComment());
  	}
  
  	protected void process(Properties properties, List<PropertyProcessor> processors) {
  		if (processors == null) {
  			return;
  		}
  		for (PropertyProcessor processor : processors) {
  			processor.process(properties);
  		}
  	}
  
  	protected Properties loadProperties(PropertyLoadContext context) {
  		PropertyPlaceholderHelper helper = Constants.DEFAULT_PROPERTY_PLACEHOLDER_HELPER;
  		context.initializeLoadProcessors();
  		Properties properties = new Properties();
  		for (String location : context.getLocations()) {
  			Properties duplicate = PropertyUtils.duplicate(properties);
  			process(duplicate, context.getLoadProcessors());
  			String resolvedLocation = helper.replacePlaceholders(location, duplicate);
  			if (!location.equals(resolvedLocation)) {
  				logger.debug("Resolved location [{}] -> [{}]", location, resolvedLocation);
  			}
  			if (LocationUtils.exists(resolvedLocation)) {
  				Properties newProperties = PropertyUtils.load(resolvedLocation, context.getEncoding());
  				properties.putAll(newProperties);
  			} else {
  				ModeUtils.validate(context.getMissingLocationsMode(), "Skipping non-existent location - [{}]", resolvedLocation, "Could not locate [" + resolvedLocation + "]");
  			}
  		}
  		return properties;
  	}
  }