/**
    *    Copyright 2015 the original author or authors.
    *
    *    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 org.mybatis.caches.redis;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.util.Map;
  import java.util.Properties;
  
  import org.apache.ibatis.cache.CacheException;
  import org.apache.ibatis.reflection.MetaObject;
  import org.apache.ibatis.reflection.SystemMetaObject;
  
  /**
   * Converter from the Config to a proper {@link RedisConfig}.
   *
   * @author Eduardo Macarron
   */
  final class RedisConfigurationBuilder {
  
  	/**
  	 * This class instance.
  	 */
  	private static final RedisConfigurationBuilder INSTANCE = new RedisConfigurationBuilder();
  
  	private static final String SYSTEM_PROPERTY_REDIS_PROPERTIES_FILENAME = "redis.properties.filename";
  
  	private static final String REDIS_RESOURCE = "redis.properties";
  
  	private final String redisPropertiesFilename;
  
  	/**
  	 * Hidden constructor, this class can't be instantiated.
  	 */
  	private RedisConfigurationBuilder() {
  		redisPropertiesFilename = System.getProperty(SYSTEM_PROPERTY_REDIS_PROPERTIES_FILENAME, REDIS_RESOURCE);
  	}
  
  	/**
  	 * Return this class instance.
  	 *
  	 * @return this class instance.
  	 */
  	public static RedisConfigurationBuilder getInstance() {
  		return INSTANCE;
  	}
  
  	/**
  	 * Parses the Config and builds a new {@link RedisConfig}.
  	 *
  	 * @return the converted {@link RedisConfig}.
  	 */
  	public RedisConfig parseConfiguration() {
  		return parseConfiguration(getClass().getClassLoader());
  	}
  
  	/**
  	 * Parses the Config and builds a new {@link RedisConfig}.
  	 *
  	 * @param the
  	 *            {@link ClassLoader} used to load the
  	 *            {@code memcached.properties} file in classpath.
  	 * @return the converted {@link RedisConfig}.
  	 */
  	public RedisConfig parseConfiguration(ClassLoader classLoader) {
  		Properties config = new Properties();
  
  		InputStream input = classLoader.getResourceAsStream(redisPropertiesFilename);
  		if (input != null) {
  			try {
  				config.load(input);
  			} catch (IOException e) {
  				throw new RuntimeException(
  						"An error occurred while reading classpath property '"
  								+ redisPropertiesFilename
  								+ "', see nested exceptions", e);
  			} finally {
  				try {
  					input.close();
  				} catch (IOException e) {
  					// close quietly
  				}
  			}
  		}
  
  		RedisConfig jedisConfig = new RedisConfig();
 		setConfigProperties(config, jedisConfig);
 		return jedisConfig;
 	}
 
 	private void setConfigProperties(Properties properties,
 			RedisConfig jedisConfig) {
 		if (properties != null) {
 			MetaObject metaCache = SystemMetaObject.forObject(jedisConfig);
 			for (Map.Entry<Object, Object> entry : properties.entrySet()) {
 				String name = (String) entry.getKey();
 				String value = (String) entry.getValue();
 				if (metaCache.hasSetter(name)) {
 					Class<?> type = metaCache.getSetterType(name);
 					if (String.class == type) {
 						metaCache.setValue(name, value);
 					} else if (int.class == type || Integer.class == type) {
 						metaCache.setValue(name, Integer.valueOf(value));
 					} else if (long.class == type || Long.class == type) {
 						metaCache.setValue(name, Long.valueOf(value));
 					} else if (short.class == type || Short.class == type) {
 						metaCache.setValue(name, Short.valueOf(value));
 					} else if (byte.class == type || Byte.class == type) {
 						metaCache.setValue(name, Byte.valueOf(value));
 					} else if (float.class == type || Float.class == type) {
 						metaCache.setValue(name, Float.valueOf(value));
 					} else if (boolean.class == type || Boolean.class == type) {
 						metaCache.setValue(name, Boolean.valueOf(value));
 					} else if (double.class == type || Double.class == type) {
 						metaCache.setValue(name, Double.valueOf(value));
 					} else {
 						throw new CacheException("Unsupported property type: '"
 								+ name + "' of type " + type);
 					}
 				}
 			}
 		}
 	}
 
 }