/*
    * 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.CategoryBag;
  import org.apache.juddi.datatype.KeyedReference;
  import org.apache.juddi.datatype.request.FindQualifiers;
  import org.apache.juddi.datatype.tmodel.TModel;
  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 FindTModelByCategoryQuery
  {
    // private reference to the jUDDI logger
    private static Log log = LogFactory.getLog(FindTModelByCategoryQuery.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 M.TMODEL_KEY,M.LAST_UPDATE ");
      sql.append("FROM ").append(tablePrefix).append("TMODEL M,").append(tablePrefix).append("TMODEL_CATEGORY C ");
      selectSQL = sql.toString();
    }
  
    /***
     * Select ...
     *
     * @param connection JDBC connection
     * @throws java.sql.SQLException
     */
    public static Vector select(CategoryBag categoryBag,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,categoryBag,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));//("TMODEL_KEY"));
  
        return keysOut;
      }
      finally
      {
        try {
          resultSet.close();
        }
        catch (Exception e)
        {
          log.warn("An Exception was encountered while attempting to close " +
           "the Find TModel ResultSet: "+e.getMessage(),e);
       }
 
       try {
         statement.close();
       }
       catch (Exception e)
       {
         log.warn("An Exception was encountered while attempting to close " +
           "the Find TModel Statement: "+e.getMessage(),e);
       }
     }
   }
 
   /***
    *
    */
   private static void appendWhere(DynamicQuery sql,CategoryBag categoryBag,FindQualifiers qualifiers)
   {
     sql.append("WHERE M.TMODEL_KEY = C.TMODEL_KEY ");
 
     if (categoryBag != null)
     {
       Vector keyedRefVector = categoryBag.getKeyedReferenceVector();
 
       if (keyedRefVector != null)
       {
         int vectorSize = keyedRefVector.size();
         if (vectorSize > 0)
         {
           sql.append("AND (");
 
           for (int i=0; i<vectorSize; i++)
           {
             KeyedReference keyedRef = (KeyedReference)keyedRefVector.elementAt(i);
             String key = keyedRef.getTModelKey();
             String name = keyedRef.getKeyName();
             String value = keyedRef.getKeyValue();
             
             if (name == null)
               name = "";
             
             if (value == null)
               value = "";
             
             // If the tModelKey involved is that of uddi-org:general_keywords, 
             // the keyNames are identical (DO NOT IGNORE keyName). Otherwise 
             // keyNames are not significant. Omitted keyNames are treated as 
             // identical to empty (zero length) keyNames.
             //
             if (key == null || key.length() == 0 || key.equals(TModel.GENERAL_KEYWORDS_TMODEL_KEY)) 
             {
               sql.append("(C.TMODEL_KEY_REF = ? AND C.KEY_NAME = ? AND C.KEY_VALUE = ?)");
               sql.addValue(TModel.GENERAL_KEYWORDS_TMODEL_KEY);
               sql.addValue(name);
               sql.addValue(value);
 
               if (i+1 < vectorSize)
                 sql.append(" OR ");
             }
             else 
             {
               sql.append("(C.TMODEL_KEY_REF = ? AND C.KEY_VALUE = ?)");
               sql.addValue(key);
               sql.addValue(value);
 
               if (i+1 < vectorSize)
                 sql.append(" OR ");       
             }
           }
 
           sql.append(") ");
         }
       }
     }
   }
 
   /***
    * Select ...
    *
    * @param connection JDBC connection
    * @throws java.sql.SQLException
    */
   public static Vector select(KeyedReference keyedRef,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,keyedRef,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));//("TMODEL_KEY"));
 
       return keysOut;
     }
     finally
     {
       try {
         resultSet.close();
       }
       catch (Exception e)
       {
         log.warn("An Exception was encountered while attempting to close " +
           "the Find TModel ResultSet: "+e.getMessage(),e);
       }
 
       try {
         statement.close();
       }
       catch (Exception e)
       {
         log.warn("An Exception was encountered while attempting to close " +
           "the Find TModel Statement: "+e.getMessage(),e);
       }
     }
   }
 
   /***
    *
    */
   private static void appendWhere(DynamicQuery sql,KeyedReference keyedRef,FindQualifiers qualifiers)
   {
     sql.append("WHERE M.TMODEL_KEY = C.TMODEL_KEY ");
 
     if (keyedRef != null)
     {
       sql.append("AND (");
 
       String key = keyedRef.getTModelKey();
       String name = keyedRef.getKeyName();
       String value = keyedRef.getKeyValue();
         
       if (name == null)
         name = "";
         
       if (value == null)
         value = "";
         
       // If the tModelKey involved is that of uddi-org:general_keywords, 
       // the keyNames are identical (DO NOT IGNORE keyName). Otherwise 
       // keyNames are not significant. Omitted keyNames are treated as 
       // identical to empty (zero length) keyNames.
       //
       if (key.equals(TModel.GENERAL_KEYWORDS_TMODEL_KEY)) 
       {
         sql.append("(C.TMODEL_KEY_REF = ? AND C.KEY_NAME = ? AND C.KEY_VALUE = ?)");
         sql.addValue(key);
         sql.addValue(name);
         sql.addValue(value);
       }
       else 
       {
         sql.append("(C.TMODEL_KEY_REF = ? AND C.KEY_VALUE = ?)");
         sql.addValue(key);
         sql.addValue(value);
       }
 
       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 M.TMODEL_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("M.LAST_UPDATE DESC");
     else if (qualifiers.sortByDateAsc)
       sql.append("M.LAST_UPDATE ASC");
     else
       sql.append("M.LAST_UPDATE DESC");
   }
 }