source: trunk/gsdl3/src/java/org/greenstone/gsdl3/gs3build/classifier/AbstractHierarchyNode.java@ 6288

package org.greenstone.gsdl3.gs3build.classifier;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.greenstone.gsdl3.gs3build.doctypes.DocumentID;

import org.greenstone.gsdl3.gs3build.util.GS3SQLConnection;
import org.greenstone.gsdl3.gs3build.database.*;

public abstract class AbstractHierarchyNode
{
  String prefix;        // a basic prefix used in this hierarchy
  String descriptor;    // the textual descriptor used on screen or long-hand
  String name;          // the index number, letter assignment or other item
                        //   used to identify the position of the item in the
                        //   hierarchy
  String id;            // an identifier used by the GLI for maintenance
                        //   purposes; this plays no active role in the
                        //   rebuilding process (at the moment)
  List childNodes;      // the child classification nodes of this node
  List childDocs;       // the child documents of this node
  List matches;         // the other metadata values that may be matched
                        //   against the classifier
  AbstractHierarchyNode parent; // the parent of the node

  /**
   *  Simple node
   */
  public AbstractHierarchyNode()
  { this.descriptor = null;
    this.name       = null;
    this.id         = null;
    this.prefix     = null;
    this.childNodes = new ArrayList();
    this.childDocs  = new ArrayList();
    this.parent     = null;
    this.matches    = new ArrayList();
  }
    
  public AbstractHierarchyNode(String prefix, String name, String id, String descriptor)
  { this.descriptor = descriptor;
    this.name       = name;
    this.id         = id;
    this.prefix     = prefix;
    this.childNodes = new ArrayList();
    this.childDocs  = new ArrayList();
    this.parent     = null;
    this.matches    = new ArrayList();
    this.matches.add(this.id);
  }
    
  public void addChild(AbstractHierarchyNode child)
  { this.childNodes.add(child);
    child.setParent(this);

    if (this.id == null) {
      System.out.println(child.id.toString() + " added to root");
    }
    else {
      System.out.println(child.id.toString() + " added to " + this.id);
    }
  }

  public boolean add(AbstractHierarchyNode child)
  { if (this.id != null &&
        !child.id.startsWith(this.id + "."))
    { return false;
    }

    Iterator subNodes = this.childNodes.iterator();
    while (subNodes.hasNext()) {
      AbstractHierarchyNode subNode = (AbstractHierarchyNode) subNodes.next();
      
      if (subNode.add(child)) {
    return true;
      }
    }
    
    this.addChild(child);
    return true;
  }

  public void addDocument(DocumentID document)
  { this.childDocs.add(document);
  }

  public void setParent(AbstractHierarchyNode parent)
  { this.parent = parent;
  }
    
  public AbstractHierarchyNode getParent()
  { return this.parent;
  }

  public String getParentId()
  { 
    if (this.id == null) {
      return "";
    }

    int dotAt = this.id.lastIndexOf('.');
    if (dotAt < 0) {
      return "";
    }
    return this.id.substring(0, dotAt);
  }  

  public void setDescriptor(String descriptor)
  { this.descriptor = descriptor;
  }

  public void setID(String id)
  { this.id = id;
    this.matches.add(id);
  }

  public String getID()
  { return this.id;
  }

  /**
   *  Set the name for this hierarchy node - i.e. its brief description
   *
   *  @param <code>String</code> the new node name.
   */
  public void setName(String name)
  { this.name = name;
  }

  /**
   *  Get the name for this hierarchy node - i.e. its brief description
   *
   *  @return <code>String</code> the node's name.
   */
  public String getName()
  { return this.name;
  }

  /**
   *  Add another string which can be used to describe this hierarchy node - i.e. one which if
   *  found in a document would indicate that that document belongs to this hierarchy node.
   *
   *  @param <code>String</code> the string to match.
   */
  public void addMatch(String match)
  { this.matches.add(match);
  }

  /**
   *  Check if a given string matches any of the values given for this hierarchy node...
   *
   *  @param <code>String</code> the descriptive string to be compared against the hierarchy
   *  @return <code>boolean</code> <code>true</code> whether the string matches this hierarchy
   */
  public boolean isMatch (String toMatch)
  { Iterator thisMatch = this.matches.iterator();
            
    while (thisMatch.hasNext())
    { String thisMatchText = thisMatch.next().toString();
      
      if (thisMatchText.equals(toMatch))
      { return true;
      }
    }
    return false;
  }

  /**
   *  Take a document, and find the classifications that it matches against in
   *  the current hierarchy.  
   *
   *  @param <code>DocumentID</code> the id of the document being classified
   *  @param <code>List</code> the values against which the classifier should
   *         test for the document being a match - i.e. the pertinent document
   *         property values.
   *  @param <code>ClassifierObserverInterface</code>
   *         object modifies the document with information about the
   *         classifications that it fell within.
   */
  abstract public void getClassifications(DocumentID documentID, List values, 
                      ClassifierObserverInterface observer);

  public boolean writeSQL(GS3SQLConnection connection)
  {
    int classifyRef;
    GS3SQLAction action;
    GS3SQLSelect select;
    GS3SQLInsert insert;

    // check for an existing instance of this classifier
    select = new GS3SQLSelect("classifiers");
    select.addField("ClassifyRef");
    GS3SQLWhereItem whereItem = new GS3SQLWhereItem("ClassifyID", "=", this.prefix+"."+this.id);
    GS3SQLWhere where = new GS3SQLWhere(whereItem);
    select.setWhere(where);

    connection.execute(select.toString());

    // update or insert the classifier as required
    try {
      ResultSet results = connection.getResultSet();
      if (results != null && results.first()) {
    GS3SQLUpdate update = new GS3SQLUpdate("classifiers");
    update.setWhere(where);
    action = update;
 
    classifyRef = results.getInt("ClassifyRef");
      }
      else {
    insert = new GS3SQLInsert("classifiers");

    String parentId = this.getParentId();

    if (parentId.length() > 0) {
      insert.addValue("ParentID", this.prefix+"."+this.getParentId());
    }
    else {
      insert.addValue("ParentID", this.prefix);
    }

    action = insert;
      }
      action.addValue("ClassifyID", this.prefix+"."+this.id);
      action.addValue("Name", this.name);
      action.addValue("Description", this.descriptor);

      connection.execute(action.toString());
      classifyRef = -1;
    }
    catch (SQLException sqlEx) {
      System.err.println(sqlEx);
      return false;
    }

    // get the ClassifyRef if we don't already have it (have done a
    // insert action above)...
    if (classifyRef == -1) {
      connection.execute(select.toString());
      
      try {
    ResultSet results = connection.getResultSet();
    if (results == null || !results.first()) {
      return false;
    }
    
    classifyRef = results.getInt("ClassifyRef");
      }
      catch (SQLException sqlEx) {
    System.err.println(sqlEx);
    return false;
      }
    }
    else {
      // TODO: clear 'dead' child classifications

      // delete child documents
      GS3SQLDelete delete = new GS3SQLDelete("classdocuments");
      delete.setWhere(where);

      connection.execute(delete.toString());
    }

    // post the child nodes...
    Iterator iterator = this.childNodes.iterator();
    while (iterator.hasNext()) {
      AbstractHierarchyNode childNode = (AbstractHierarchyNode) iterator.next();

      if (!childNode.writeSQL(connection)) {
    return false;
      }
    }

    // note the child documents...
    iterator = this.childDocs.iterator();
    while (iterator.hasNext()) {
      DocumentID docId = (DocumentID) iterator.next();
      insert = new GS3SQLInsert("classdocuments");
      insert.addValue("ClassifyRef", Integer.toString(classifyRef), GS3SQLField.INTEGER_TYPE);
      insert.addValue("DocID", docId.toString());

      connection.execute(insert.toString());
    }
    return true;
  }
}