/**
    * Copyright 2010-2013 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.jdbc.supplier;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.kuali.common.util.Assert;
  import org.kuali.common.util.CollectionUtils;
  import org.kuali.common.util.LocationUtils;
  import org.kuali.common.util.ReflectionUtils;
  import org.kuali.common.util.spring.SpringUtils;
  import org.springframework.beans.BeanUtils;
  import org.springframework.beans.factory.FactoryBean;
  import org.springframework.core.env.Environment;
  
  public class LocationSuppliersFactoryBean implements FactoryBean<List<LocationSupplier>> {
  
  	public static final String DEFAULT_LIST_SUFFIX = ".list";
  
  	String listSuffix = DEFAULT_LIST_SUFFIX;
  	Environment env;
  	String property;
  	Map<String, LocationSupplierSourceBean> extensionMappings;
  
  	@Override
  	public List<LocationSupplier> getObject() {
  
  		// Make sure we are configured correctly
  		Assert.notNull(env, "environment is null");
  		Assert.notNull(property, "property is null");
  		Assert.notNull(extensionMappings, "extensionMappings is null");
  
  		// Get a list of locations using properties, prefix, and listSuffix
  		List<String> locations = getLocations(env, property, listSuffix);
  
  		// Convert the locations into LocationSupplier's based on extension
  		return getSuppliers(locations, extensionMappings);
  	}
  
  	protected List<LocationSupplier> getSuppliers(List<String> locations, Map<String, LocationSupplierSourceBean> mappings) {
  		// Allocate some storage for our suppliers
  		List<LocationSupplier> suppliers = new ArrayList<LocationSupplier>();
  
  		// Cycle through the list of locations, creating one supplier per location
  		for (String location : locations) {
  
  			// Extract the extension from the location
  			String extension = FilenameUtils.getExtension(location);
  
  			// The map holds the concrete LocationSupplier implementation to use for each extension
  			LocationSupplierSourceBean sourceBean = mappings.get(extension);
  
  			// Unknown extension type
  			if (sourceBean == null) {
  				throw new IllegalArgumentException("Unknown extension [" + extension + "]");
  			}
  
  			// Request a new supplier from the builder
  			LocationSupplier supplier = sourceBean.getSupplierInstance();
  
  			LocationSupplier newInstance = ReflectionUtils.newInstance(supplier.getClass());
  			BeanUtils.copyProperties(supplier, newInstance);
  			newInstance.setLocation(location);
  
  			// Add it to the list
  			suppliers.add(newInstance);
  		}
  
  		// Return the fully configured list of suppliers
  		return suppliers;
  	}
  
  	protected List<String> getLocations(Environment env, String property, String listSuffix) {
  
  		// Extract the list of property keys (comma delimited)
  		String csv = SpringUtils.getProperty(env, property, "");
  
  		// If no keys were provided, we are done
  		if (StringUtils.isBlank(csv)) {
  			return new ArrayList<String>();
  		}
  
 		// Parse the property keys into a list
 		List<String> keys = CollectionUtils.getTrimmedListFromCSV(csv);
 
 		// Allocate some storage for the locations we find
 		List<String> locations = new ArrayList<String>();
 		for (String key : keys) {
 
 			// This is a either a list of locations or a location itself
 			String value = SpringUtils.getProperty(env, key);
 
 			if (StringUtils.endsWithIgnoreCase(key, listSuffix)) {
 				// If the key ends with .list, it's a list of locations
 				locations.addAll(LocationUtils.getLocations(value));
 			} else {
 				// Otherwise it is a location itself
 				locations.add(value);
 			}
 		}
 
 		// Return the list of locations
 		return locations;
 	}
 
 	@Override
 	public Class<?> getObjectType() {
 		return List.class;
 	}
 
 	@Override
 	public boolean isSingleton() {
 		return false;
 	}
 
 	public String getListSuffix() {
 		return listSuffix;
 	}
 
 	public void setListSuffix(String listSuffix) {
 		this.listSuffix = listSuffix;
 	}
 
 	public Map<String, LocationSupplierSourceBean> getExtensionMappings() {
 		return extensionMappings;
 	}
 
 	public void setExtensionMappings(Map<String, LocationSupplierSourceBean> extensionMappings) {
 		this.extensionMappings = extensionMappings;
 	}
 
 	public String getProperty() {
 		return property;
 	}
 
 	public void setProperty(String property) {
 		this.property = property;
 	}
 
 	public Environment getEnv() {
 		return env;
 	}
 
 	public void setEnv(Environment env) {
 		this.env = env;
 	}
 
 }