/*

  * Copyright 2006-2011 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.rice.krad.service.impl;

 import org.apache.commons.lang.StringUtils;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.config.property.ConfigContext;

 import org.kuali.rice.core.api.config.property.ConfigurationService;

 import org.kuali.rice.core.api.util.Truth;

 import org.kuali.rice.kns.web.struts.action.KualiPropertyMessageResources;

 import org.kuali.rice.kns.web.struts.action.KualiPropertyMessageResourcesFactory;

 import org.kuali.rice.krad.exception.DuplicateKeyException;

 import org.kuali.rice.krad.exception.PropertiesException;

 import java.io.IOException;

 import java.io.InputStream;

 import java.net.URL;

 import java.util.Collections;

 import java.util.Iterator;

 import java.util.Map;

 import java.util.Properties;

 public class ConfigurationServiceImpl implements ConfigurationService {

     private final PropertyHolder propertyHolder = new PropertyHolder();

     /**

      * Harcoding the configFileName, by request.

      */

     public ConfigurationServiceImpl() {

         this.propertyHolder.getHeldProperties().putAll(ConfigContext.getCurrentContextConfig().getProperties());

         KualiPropertyMessageResourcesFactory propertyMessageFactory = new KualiPropertyMessageResourcesFactory();

         // create default KualiPropertyMessageResources

         KualiPropertyMessageResources messageResources =

                 (KualiPropertyMessageResources) propertyMessageFactory.createResources("");

         //Add Kuali Properties to property holder

         this.propertyHolder.getHeldProperties().putAll(messageResources.getKualiProperties(null));

     }

     /**

      * @see org.kuali.rice.core.api.config.property.ConfigurationService#getPropertyValueAsString(java.lang.String)

      */

     @Override

     public String getPropertyValueAsString(String key) {

         if (key == null) {

             throw new IllegalArgumentException("invalid (null) key");

         }

         return this.propertyHolder.getProperty(key);

     }

     /**

      * @see org.kuali.rice.core.api.config.property.ConfigurationService#getPropertyValueAsBoolean(java.lang.String)

      */

     @Override

     public boolean getPropertyValueAsBoolean(String key) {

         if (key == null) {

             throw new IllegalArgumentException("invalid (null) key");

         }

         String property = this.propertyHolder.getProperty(key);

         Boolean b = Truth.strToBooleanIgnoreCase(property);

         if (b == null) {

             return false;

         }

         return b;

     }

     /**

      * @see org.kuali.rice.core.api.config.property.ConfigurationService#getAllProperties()

      */

     @Override

     public Map<String, String> getAllProperties() {

         return (Map) Collections.unmodifiableMap(propertyHolder.getHeldProperties());

     }

     /**

      * This is an interface for a source for properties

      *

      *

      */

     static interface PropertySource {

         /**

          * @return Properties loaded from this PropertySource

          * @throws org.kuali.rice.krad.exception.PropertiesException if there's a problem loading the properties

          */

         public Properties loadProperties();

     }

     /**

      * This class is a Property container. It is able to load properties from various property-sources.

      *

      *

      */

     static class PropertyHolder {

         private static Logger LOG = Logger.getLogger(PropertyHolder.class);

         Properties heldProperties;

         /**

          * Default constructor.

          */

         public PropertyHolder() {

             this.heldProperties = new Properties();

         }

         /**

          * @return true if this container currently has no properties

          */

         public boolean isEmpty() {

             return this.heldProperties.isEmpty();

         }

         /**

          * @param key

          * @return true if a property with the given key exists in this container

          * @throws IllegalArgumentException if the given key is null

          */

         public boolean containsKey(String key) {

             validateKey(key);

             return this.heldProperties.containsKey(key);

         }

         /**

          * @param key

          * @return the current value of the property with the given key, or null if no property exists with that key

          * @throws IllegalArgumentException if the given key is null

          */

         public String getProperty(String key) {

             validateKey(key);

             return this.heldProperties.getProperty(key);

         }

         /**

          * Associates the given value with the given key

          *

          * @param key

          * @param value

          * @throws IllegalArgumentException if the given key is null

          * @throws IllegalArgumentException if the given value is null

          * @throws org.kuali.rice.krad.exception.DuplicateKeyException if a property with the given key already exists

          */

         public void setProperty(String key, String value) {

         setProperty(null, key, value);

         }

         /**

          * Associates the given value with the given key

          *

          * @param source

          * @param key

          * @param value

          * @throws IllegalArgumentException if the given key is null

          * @throws IllegalArgumentException if the given value is null

          * @throws org.kuali.rice.krad.exception.DuplicateKeyException if a property with the given key already exists

          */

         public void setProperty(PropertySource source, String key, String value) {

             validateKey(key);

             validateValue(value);

             if (containsKey(key)) {

                 if (source != null && source instanceof FilePropertySource && ((FilePropertySource)source).isAllowOverrides()) {

                     LOG.info("Duplicate Key: Override is enabled [key=" + key + ", new value=" + value + ", old value=" + this.heldProperties.getProperty(key) + "]");

                 } else {

                     throw new DuplicateKeyException("duplicate key '" + key + "'");

                 }

             }

             this.heldProperties.setProperty(key, value);

         }

         /**

          * Removes the property with the given key from this container

          *

          * @param key

          * @throws IllegalArgumentException if the given key is null

          */

         public void clearProperty(String key) {

             validateKey(key);

             this.heldProperties.remove(key);

         }

         /**

          * Copies all name,value pairs from the given PropertySource instance into this container.

          *

          * @param source

          * @throws IllegalStateException if the source is invalid (improperly initialized)

          * @throws org.kuali.rice.krad.exception.DuplicateKeyException the first time a given property has the same key as an existing property

          * @throws org.kuali.rice.krad.exception.PropertiesException if unable to load properties from the given source

          */

         public void loadProperties(PropertySource source) {

             if (source == null) {

                 throw new IllegalArgumentException("invalid (null) source");

             }

             Properties newProperties = source.loadProperties();

             for (Iterator i = newProperties.keySet().iterator(); i.hasNext();) {

                 String key = (String) i.next();

                 setProperty(source, key, newProperties.getProperty(key));

             }

         }

         /**

          * Removes all properties from this container.

          */

         public void clearProperties() {

             this.heldProperties.clear();

         }

         /**

          * @return iterator over the keys of all properties in this container

          */

         public Iterator getKeys() {

             return this.heldProperties.keySet().iterator();

         }

         /**

          * @param key

          * @throws IllegalArgumentException if the given key is null

          */

         private void validateKey(String key) {

             if (key == null) {

                 throw new IllegalArgumentException("invalid (null) key");

             }

         }

         /**

          * @param value

          * @throws IllegalArgumentException if the given value is null

          */

         private void validateValue(String value) {

             if (value == null) {

                 throw new IllegalArgumentException("invalid (null) value");

             }

         }

         public Properties getHeldProperties() {

             return heldProperties;

         }

         public void setHeldProperties(Properties heldProperties) {

             this.heldProperties = heldProperties;

         }

     }

     /**

      * This class is used to obtain properties from a properites file.

      *

      *

      */

     static class FilePropertySource implements PropertySource {

         private static Log log = LogFactory.getLog(FilePropertySource.class);

         private String fileName;

         private boolean allowOverrides;

         /**

          * Set source fileName.

          *

          * @param fileName

          */

         public void setFileName(String fileName) {

             this.fileName = fileName;

         }

         /**

          * @return source fileName

          */

         public String getFileName() {

             return this.fileName;

         }

         public boolean isAllowOverrides() {

             return this.allowOverrides;

         }

         public void setAllowOverrides(boolean allowOverrides) {

             this.allowOverrides = allowOverrides;

         }

         /**

          * Attempts to load properties from a properties file which has the current fileName and is located on the classpath.

          *

          * @see org.kuali.rice.krad.service.impl.ConfigurationServiceImpl.PropertySource#loadProperties()

          * @throws IllegalStateException if the fileName is null or empty

          */

         public Properties loadProperties() {

             if (StringUtils.isBlank(getFileName())) {

                 throw new IllegalStateException("invalid (blank) fileName");

             }

             Properties properties = new Properties();

             ClassLoader loader = Thread.currentThread().getContextClassLoader();

             URL url = loader.getResource(getFileName());

             if (url == null) {

                 throw new PropertiesException("unable to locate properties file '" + getFileName() + "'");

             }

             InputStream in = null;

             try {

                 in = url.openStream();

                 properties.load(in);

             }

             catch (IOException e) {

                 throw new PropertiesException("error loading from properties file '" + getFileName() + "'", e);

             }

             finally {

                 if (in != null) {

                     try {

                         in.close();

                     }

                     catch (IOException e) {

                         log.error("caught exception closing InputStream: " + e);

                     }

                 }

             }

             return properties;

         }

     }

 }