package com.ctrip.framework.apollo.internals;

 import com.ctrip.framework.apollo.core.enums.ConfigFileFormat;

 import com.ctrip.framework.apollo.exceptions.ApolloConfigException;

 import com.ctrip.framework.apollo.util.ExceptionUtil;

 import com.dianping.cat.Cat;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import java.io.IOException;

 import java.io.StringWriter;

 import java.util.Properties;

 import java.util.concurrent.atomic.AtomicReference;

 /**

  * @author Jason Song(song_s@ctrip.com)

  */

 public class PropertiesConfigFile extends AbstractConfigFile {

   private static final Logger logger = LoggerFactory.getLogger(PropertiesConfigFile.class);

   protected AtomicReference<String> m_contentCache;

   public PropertiesConfigFile(String namespace,

                               ConfigRepository configRepository) {

     super(namespace, configRepository);

     m_contentCache = new AtomicReference<>();

   }

   @Override

   public String getContent() {

     if (m_contentCache.get() == null) {

       m_contentCache.set(doGetContent());

     }

     return m_contentCache.get();

   }

   String doGetContent() {

     if (m_configProperties.get() == null) {

       return null;

     }

     StringWriter writer = new StringWriter();

     try {

       m_configProperties.get().store(writer, null);

       StringBuffer stringBuffer = writer.getBuffer();

       filterPropertiesComment(stringBuffer);

       return stringBuffer.toString();

     } catch (IOException ex) {

       ApolloConfigException exception =

           new ApolloConfigException(String

               .format("Parse properties file content failed for namespace: %s, cause: %s",

                   m_namespace, ExceptionUtil.getDetailMessage(ex)));

       Cat.logError(exception);

       throw exception;

     }

   }

   /**

    * filter out the first comment line

    * @param stringBuffer the string buffer

    * @return true if filtered successfully, false otherwise

    */

   boolean filterPropertiesComment(StringBuffer stringBuffer) {

     //check whether has comment in the first line

     if (stringBuffer.charAt(0) != '#') {

       return false;

     }

     int commentLineIndex = stringBuffer.indexOf("\n");

     if (commentLineIndex == -1) {

       return false;

     }

     stringBuffer.delete(0, commentLineIndex + 1);

     return true;

   }

   @Override

   public boolean hasContent() {

     return m_configProperties.get() != null && !m_configProperties.get().isEmpty();

   }

   @Override

   public ConfigFileFormat getConfigFileFormat() {

     return ConfigFileFormat.Properties;

   }

   @Override

   public synchronized void onRepositoryChange(String namespace, Properties newProperties) {

     super.onRepositoryChange(namespace, newProperties);

     m_contentCache.set(null);

   }

 }