package uk.ac.ebi.intenz.mapper;

 import java.sql.Connection;

 import java.sql.PreparedStatement;

 import java.sql.ResultSet;

 import java.sql.SQLException;

 import java.sql.Timestamp;

 import java.util.Date;

 import java.util.Hashtable;

 import java.util.List;

 import java.util.Vector;

 import org.apache.log4j.Logger;

 import uk.ac.ebi.intenz.domain.constants.EventConstant;

 import uk.ac.ebi.intenz.domain.enzyme.EnzymeEntry;

 import uk.ac.ebi.intenz.domain.exceptions.DomainException;

 import uk.ac.ebi.intenz.domain.history.HistoryEvent;

 import uk.ac.ebi.intenz.domain.history.HistoryGraph;

 import uk.ac.ebi.intenz.domain.history.HistoryNode;

 /**

  * Maps history event information to the corresponding database tables.

  *

  * @author Michael Darsow

  * @version $Revision: 1.3 $ $Date: 2009/05/26 14:59:09 $

  */

 public class EnzymeHistoryMapper {

   private Logger LOGGER = Logger.getLogger(EnzymeHistoryMapper.class.getName());

   protected Hashtable visitedNodes;

   private static final String COLUMNS = "group_id, event_id, before_id, after_id, event_year, event_note, event_class";

   public EnzymeHistoryMapper() {

     visitedNodes = new Hashtable();

   }

   private String findStatement() {

     return "SELECT " + COLUMNS +

            " FROM history_events WHERE before_id = ? OR after_id = ?";

   }

   public HistoryGraph find(EnzymeEntry enzymeEntry, Connection con)

   throws SQLException, DomainException {

     if (enzymeEntry == null) throw new NullPointerException();

     HistoryNode currentNode = findNode(enzymeEntry, true, con);

     if (currentNode == null) return null;

     return new HistoryGraph(currentNode);

   }

   // ------------------- PRIVATE METHODS ------------------------

   private HistoryNode findNode(EnzymeEntry currentEntry, boolean isRoot,

                   Connection con)

   throws SQLException, DomainException {

     HistoryNode historyNode = new HistoryNode();

     historyNode.setEnzymeEntry(currentEntry);

     historyNode.setRoot(isRoot);

     // Keep history line loaded before.

     historyNode.setHistoryLine(currentEntry.getHistory().getRootNode().getHistoryLine());

     if (visitedNodes.containsKey(currentEntry.getId()))

       return (HistoryNode) visitedNodes.get(currentEntry.getId()); // Stops recursion.

     visitedNodes.put(currentEntry.getId(), historyNode);

     // Find event(s)

     List historyEvents = findHistoryEvents(historyNode, con);

     historyNode.setEdges(historyEvents);

     return historyNode;

   }

   private List findHistoryEvents(HistoryNode currentNode, Connection con)

   throws SQLException, DomainException {

     PreparedStatement findStatement = null;

     ResultSet rs = null;

     Vector result = new Vector();

     try {

       findStatement = con.prepareStatement(findStatement());

       findStatement.setLong(1, currentNode.getEnzymeEntry().getId().longValue());

       findStatement.setLong(2, currentNode.getEnzymeEntry().getId().longValue());

       rs = findStatement.executeQuery();

       while (rs.next()) {

         result.addElement(doLoad(rs, currentNode, con));

       }

     } finally {

             if (rs != null) rs.close();

       if (findStatement != null) findStatement.close();

     }

     return result;

   }

   /**

    * Creates the <code>EnzymeLink</code> object from the given result set.

    * Some modifications were made so that the timestamp could be included in the Date

    * object. In java.sql.Date the time is obsoleted to zero and only the date is

    * valid eg. 06-Jun-2005 23:34:00 in java.sql.Date becomes 06-Jun-2005 00:00:00

    *

    * @param rs The result set object.

    * @return an <code>EnzymeLink</code> instance.

    * @throws SQLException

    */

   private HistoryEvent doLoad(ResultSet rs, HistoryNode currentNode,

                   Connection con)

   throws SQLException, DomainException {

     long groupId = 0;

     long eventId = 0;

     int beforeId = 0;

     int afterId = 0;

     java.util.Date eventYear = new Date();

     String eventNote = "";

     String eventClass = "";

     if (rs.getInt("group_id") > 0) groupId = rs.getLong("group_id");

     if (rs.getInt("event_id") > 0) eventId = rs.getInt("event_id");

     if (rs.getInt("before_id") > 0) beforeId = rs.getInt("before_id");

     if (rs.getInt("after_id") > 0) afterId = rs.getInt("after_id");

     if (rs.getDate("event_year") != null){

        Timestamp ts = rs.getTimestamp("event_year");

        eventYear = new Date(ts.getTime());

     }

     if (rs.getString("event_note") != null) eventNote = rs.getString("event_note");

     if (rs.getString("event_class") != null) eventClass = rs.getString("event_class");

     // Check for relative. Either beforeNode or afterNode is different from current node or one of them is null.

     EnzymeEntryMapper enzymeEntryMapper = new EnzymeEntryMapper();

     HistoryNode beforeNode = null, afterNode = null;

     if (beforeId > 0) {

       if (beforeId != currentNode.getEnzymeEntry().getId().longValue()) {

         EnzymeEntry ghostEntry = enzymeEntryMapper.findGhostById(beforeId, con);

         beforeNode = findNode(ghostEntry, false, con);

         afterNode = currentNode;

       } else {

         beforeNode = currentNode;

       }

     }

     if (afterId > 0) {

       if (afterId != currentNode.getEnzymeEntry().getId().longValue()) {

         EnzymeEntry ghostEntry = enzymeEntryMapper.findGhostById(afterId, con);

         beforeNode = currentNode;

         afterNode = findNode(ghostEntry, false, con);

       } else {

         afterNode = currentNode;

       }

     }

     HistoryEvent historyEvent = new HistoryEvent();

     historyEvent.setGroupId(new Long(groupId));

     historyEvent.setEventId(new Long(eventId));

     historyEvent.setBeforeNode(beforeNode);

     historyEvent.setAfterNode(afterNode);

     historyEvent.setDate(eventYear);

     historyEvent.setNote(eventNote);

     historyEvent.setEventClass(EventConstant.valueOf(eventClass));

     enzymeEntryMapper.close();

     return historyEvent;

   }

 }