/*
    * Copyright 2001-2004 The Apache Software Foundation.
    * 
    * 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.apache.juddi.datastore.jdbc;
  
  import java.sql.Connection;
  import java.sql.PreparedStatement;
  import java.sql.ResultSet;
  import java.util.Vector;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.juddi.datatype.DiscoveryURL;
  import org.apache.juddi.datatype.DiscoveryURLs;
  import org.apache.juddi.datatype.request.FindQualifiers;
  import org.apache.juddi.registry.RegistryEngine;
  import org.apache.juddi.util.Config;
  import org.apache.juddi.util.jdbc.DynamicQuery;
  
  /***
   * @author Steve Viens (sviens@apache.org)
   */
  class FindBusinessByDiscoveryURLQuery
  {
    // private reference to the jUDDI logger
    private static Log log = LogFactory.getLog(FindBusinessByDiscoveryURLQuery.class);
  
    static String selectSQL;
    static String tablePrefix;
    static
    {
      tablePrefix = Config.getStringProperty(
          RegistryEngine.PROPNAME_TABLE_PREFIX,RegistryEngine.DEFAULT_TABLE_PREFIX);
      // build selectSQL
      StringBuffer sql = new StringBuffer(200);
      sql.append("SELECT B.BUSINESS_KEY,B.LAST_UPDATE ");
      sql.append("FROM ").append(tablePrefix).append("BUSINESS_ENTITY B,").append(tablePrefix).append("DISCOVERY_URL U ");
      selectSQL = sql.toString();
    }
  
    /***
     * Select ...
     *
     * @param discoveryURLs
     * @param keysIn
     * @param qualifiers
     * @param connection JDBC connection
     * @throws java.sql.SQLException
     */
    public static Vector select(DiscoveryURLs discoveryURLs,Vector keysIn,FindQualifiers qualifiers,Connection connection)
      throws java.sql.SQLException
    {
      // if there is a keysIn vector but it doesn't contain
      // any keys then the previous query has exhausted
      // all possibilities of a match so skip this call.
      if ((keysIn != null) && (keysIn.size() == 0))
        return keysIn;
  
      Vector keysOut = new Vector();
      PreparedStatement statement = null;
      ResultSet resultSet = null;
  
      // construct the SQL statement
      DynamicQuery sql = new DynamicQuery(selectSQL);
      appendWhere(sql,discoveryURLs,qualifiers);
      appendIn(sql,keysIn);
      appendOrderBy(sql,qualifiers);
  
      try
      {
        log.debug(sql.toString());
  
        statement = sql.buildPreparedStatement(connection);
        resultSet = statement.executeQuery();
  
        while (resultSet.next())
          keysOut.addElement(resultSet.getString(1));//("BUSINESS_KEY"));
  
        return keysOut;
      }
      finally
      {
        try {
          resultSet.close();
        }
        catch (Exception e)
        {
         log.warn("An Exception was encountered while attempting to close " +
           "the Find BusinessEntity ResultSet: "+e.getMessage(),e);
       }
 
       try {
         statement.close();
       }
       catch (Exception e)
       {
         log.warn("An Exception was encountered while attempting to close " +
           "the Find BusinessEntity Statement: "+e.getMessage(),e);
       }
     }
   }
 
   /***
    *
    */
   private static void appendWhere(DynamicQuery sql,DiscoveryURLs discoveryURLs,FindQualifiers qualifiers)
   {
     sql.append("WHERE B.BUSINESS_KEY = U.BUSINESS_KEY ");
 
     Vector urlVector = discoveryURLs.getDiscoveryURLVector();
 
     int vectorSize = urlVector.size();
     if (vectorSize > 0)
     {
       sql.append("AND (");
 
       for (int i=0; i<vectorSize; i++)
       {
         DiscoveryURL discoveryURL = (DiscoveryURL)urlVector.elementAt(i);
         String url = discoveryURL.getValue();
         String useType = discoveryURL.getUseType();
 
         if ((url != null) && (url.length() > 0))
         {
           sql.append("(U.URL = ?");
           sql.addValue(url);
 
           if ((useType != null) && (useType.length() > 0))
           {
             sql.append(" AND U.USE_TYPE = ?");
             sql.addValue(useType);
           }
           
           sql.append(")");
 
           if (i+1 < vectorSize)
             sql.append(" OR ");
         }
       }
 
       sql.append(") ");
     }
   }
 
   /***
    * Utility method used to construct SQL "IN" statements such as
    * the following SQL example:
    *
    *   SELECT * FROM TABLE WHERE MONTH IN ('jan','feb','mar')
    *
    * @param sql StringBuffer to append the final results to
    * @param keysIn Vector of Strings used to construct the "IN" clause
    */
   private static void appendIn(DynamicQuery sql,Vector keysIn)
   {
     if (keysIn == null)
       return;
 
     sql.append("AND B.BUSINESS_KEY IN (");
 
     int keyCount = keysIn.size();
     for (int i=0; i<keyCount; i++)
     {
       String key = (String)keysIn.elementAt(i);
       sql.append("?");
       sql.addValue(key);
 
       if ((i+1) < keyCount)
         sql.append(",");
     }
 
     sql.append(") ");
   }
 
   /***
    *
    */
   private static void appendOrderBy(DynamicQuery sql,FindQualifiers qualifiers)
   {
     sql.append("ORDER BY ");
 
     if (qualifiers == null)
       sql.append("B.LAST_UPDATE DESC");
     else if (qualifiers.sortByDateAsc)
       sql.append("B.LAST_UPDATE ASC");
     else
       sql.append("B.LAST_UPDATE DESC");
   }
 }