/*
    *
    * The DbUnit Database Testing Framework
    * Copyright (C)2002-2004, DbUnit.org
    *
    * This library is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Lesser General Public
    * License as published by the Free Software Foundation; either
    * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */
  
  package org.dbunit.ant;
  
  import java.sql.SQLException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.ProjectComponent;
  import org.apache.tools.ant.types.FilterSet;
  import org.dbunit.database.AmbiguousTableNameException;
  import org.dbunit.database.IDatabaseConnection;
  import org.dbunit.database.QueryDataSet;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * This element is a container for Queries. It facilitates reuse
   * through references. Using Ant 1.6 and greater, references can be
   * defined in a single build file and <i>import</i>ed into many others.
   * An example of where this is useful follows:
   * <p>
   * In our database
   * we have INDIVIDUALS which must have an associated NAME_INFO and
   * at least one IND_ADDRESS. The developer creating a dataset for
   * his/her tests probably won't know all the details of what relationships are
   * expected, and if he did, its an error prone and repetitive task
   * to create the correct SQL for entities in each dataset.
   * Missing a related table, not only creates invalid data for your tests,
   * but also is likely to cause DBUnit setUp() failures from foreign key
   * constraint violation errors.
   * (example: If a previous test had inserted INDIVIDUALS
   * and NAME_INFO and my test tries to delete only the INDIVIDUALS, the
   * NAME_INFO.IND_ID constraint would be violated)
   * <p>
   * <p>
   * Each queryset is internally converted to a <code>QueryDataSet</code> and then
   * combined using a <code>CompositeDataSet</code>. This means that you can use
   * more than one <code>query</code> element for any given table provided they
   * are nested within separate <code>queryset</code>s.
   * <p>
   * Usage:
   *
   * <pre>
   * &lt;!-- ======== Define the reusable reference ========== --&gt;
   *
   * &lt;queryset id="individuals"&gt;
   *    &lt;query name="INDIVIDUALS" sql="
   *      SELECT * FROM INDIVIDUALS WHERE IND_ID IN (@subQuery@)"/&gt;
   *
   *    &lt;query name="NAME_INFO" sql="
   *      SELECT B.* FROM INDIVIDUALS A, NAME_INFO B
   *      WHERE A.IND_ID IN (@subQuery@)
   *      AND B.IND_ID = A.IND_ID"/&gt;
   *
   *    &lt;query name="IND_ADDRESSES" sql="
   *      SELECT B.* FROM INDIVIDUALS A, IND_ADDRESSES B
   *      WHERE A.IND_ID IN (@subQuery@)
   *      AND B.IND_ID = A.IND_ID"/&gt;
   * &lt;/queryset&gt;
   *
   * &lt;!-- ========= Use the reference ====================== --&gt;
   *
   * &lt;dbunit driver="${jdbcDriver}"
   *     url="${jdbcURL}" userid="${jdbcUser}" password="${jdbcPassword}"&gt;
   *   &lt;export dest="${dest}"&gt;
   *   &lt;queryset refid="individuals"&gt;
   *      &lt;filterset&gt;
   *        &lt;filter token="subQuery" value="
   *          SELECT IND_ID FROM INDIVIDUALS WHERE USER_NAME = 'UNKNOWN'"/&gt;
   *      &lt;/filterset&gt;
   *   &lt;/queryset&gt;
   *
   *   &lt;/export&gt;
   * &lt;/dbunit&gt;
   *
   * </pre>
   *
  * @author Lenny Marks lenny@aps.org
  * @author Last changed by: $Author$
  * @version $Revision$ $Date$
  * @since 2.2.0 (Sep. 13 2004)
  */
 public class QuerySet extends ProjectComponent
 {
 
     /**
      * Logger for this class
      */
     private static final Logger logger = LoggerFactory.getLogger(QuerySet.class);
 
     private String id;
     private String refid;
     private List queries = new ArrayList();
     private List filterSets = new ArrayList();
 
     private static String ERR_MSG =
             "Cannot specify 'id' and 'refid' attributes together in queryset.";
 
     public QuerySet() {
         super();
     }
 
     public void addQuery(final Query query) {
         logger.debug("addQuery(query={}) - start", query);
 
         queries.add(query);
     }
 
     public void addFilterSet(final FilterSet filterSet) {
         logger.debug("addFilterSet(filterSet={}) - start", filterSet);
 
         filterSets.add(filterSet);
     }
 
     public String getId() {
         return id;
     }
 
     public String getRefid() {
         return refid;
     }
 
     public void setId(final String string) throws BuildException {
         logger.debug("setId(string={}) - start", string);
 
         if(refid != null) throw new BuildException(ERR_MSG);
         id = string;
     }
 
     public void setRefid(final String string) throws BuildException {
         logger.debug("setRefid(string={}) - start", string);
 
         if(id != null) throw new BuildException(ERR_MSG);
         refid = string;
     }
 
     public List getQueries() {
         logger.debug("getQueries() - start");
 
         final Iterator i = queries.iterator();
         while(i.hasNext()) {
             final Query query = (Query)i.next();
             replaceTokens(query);
         }
 
         return queries;
 
     }
 
     private void replaceTokens(final Query query) {
         logger.debug("replaceTokens(query={}) - start", query);
 
         final Iterator i = filterSets.iterator();
         while(i.hasNext()) {
             final FilterSet filterSet = (FilterSet)i.next();
             query.setSql(filterSet.replaceTokens(query.getSql()));
         }
     }
 
 
     public void copyQueriesFrom(final QuerySet referenced) {
         logger.debug("copyQueriesFrom(referenced={}) - start", referenced);
 
         final Iterator i = referenced.queries.iterator();
         while(i.hasNext()) {
             addQuery((Query)i.next());
         }
     }
 
     public QueryDataSet getQueryDataSet(final IDatabaseConnection connection)
             throws SQLException, AmbiguousTableNameException
     {
         logger.debug("getQueryDataSet(connection={}) - start", connection);
 
         //incorporate queries from referenced query-set
         final String refid = getRefid();
         if(refid != null) {
             final QuerySet referenced = (QuerySet)getProject().getReference(refid);
             copyQueriesFrom(referenced);
         }
 
         final QueryDataSet partialDataSet = new QueryDataSet(connection);
 
         final Iterator queriesIter = getQueries().iterator();
         while(queriesIter.hasNext()) {
             final Query query = (Query)queriesIter.next();
             partialDataSet.addTable(query.getName(), query.getSql());
         }
 
         return partialDataSet;
 
     }
 
 }