source: trunk/gli/src/org/greenstone/gatherer/cdm/Index.java@ 4932

/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *########################################################################
 */
package org.greenstone.gatherer.cdm;

import java.util.*;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.cdm.CollectionConfiguration;
import org.greenstone.gatherer.cdm.CollectionDesignManager;
import org.greenstone.gatherer.cdm.CollectionMeta;
import org.greenstone.gatherer.cdm.DOMProxyListEntry;
import org.greenstone.gatherer.msm.ElementWrapper;
import org.greenstone.gatherer.msm.MSMUtils;
import org.greenstone.gatherer.util.StaticStrings;
import org.greenstone.gatherer.util.Utility;
import org.w3c.dom.*;
/** This class encapsulates a single indexing pair.
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.3d
 */
public class Index
    implements Comparable, DOMProxyListEntry {
    /** An values of items in the index level enumeration. */
    static public final String LEVEL[] = {"document","paragraph","section"};

    private ArrayList sources = null;
    /** The level of this index (if old sckool MG). */
    private int level = -1;
    /** The element this index is based upon. */
    private Element element = null;
    /** The unique, if cryptic, identifier of an index. */
    private String id = null;

    /** Default constructor, which should only be used during DOMProxyListModel creation. */
    public Index() {
    }

    /** Constructor. */
    public Index(Element element) {
    this.element = element;
    }

    /** Constructor for a newly assigned index. */
    public Index(ArrayList sources) {
    this.sources = sources;
    // Create a new element
    Document document = CollectionDesignManager.collect_config.document;
    element = document.createElement(CollectionConfiguration.INDEX_ELEMENT);
    // For each source add a content element
    int size = sources.size();
    for(int i = 0; i < size; i++) {
        Element content_element = document.createElement(CollectionConfiguration.CONTENT_ELEMENT);
        Object source_object = sources.get(i);
        if(source_object instanceof ElementWrapper) {
        content_element.setAttribute(CollectionConfiguration.NAME_ATTRIBUTE, ((ElementWrapper)source_object).getName());
        }
        else {
        content_element.setAttribute(CollectionConfiguration.NAME_ATTRIBUTE, source_object.toString());
        }
        element.appendChild(content_element);
        content_element = null;
    }
    document = null;
    }

    /** Constructor for a newly assigned index with specified level (old skool). */
    public Index(int level, ArrayList sources) {
    this(sources);
    this.level = level;
    element.setAttribute(CollectionConfiguration.LEVEL_ATTRIBUTE, LEVEL[level]);
    }

    /** Method to compare two indexes.
     * @param object The other index as an <strong>Object</strong>.
     * @return An <i>int</i> which indicates how the indexes compare.
     * @see java.lang.String
     */
    public int compareTo(Object object) {
    return id.compareTo(((Index)object).getID());
    }
    
    public DOMProxyListEntry create(Element element) {
    return new Index(element);
    }

    /** Method to test for the equality of two indexes.
     * @param object The other index as an <strong>Object</strong>.
     * @return A <i>boolean</i> which is <i>true</i> if the two indexes are equal, <i>false</i> otherwise.
     */
    public boolean equals(Object object) {
    return (compareTo(object) == 0);
    }
    
    public Element getElement() {
    return element;
    }
    
    /** Method to get the value of level.
     * @return the level as a int
     */
    public int getLevel() {
    if(level == -1) {
        String level_str = element.getAttribute(CollectionConfiguration.LEVEL_ATTRIBUTE);
        for(int i = 0; level == -1 && i < LEVEL.length; i++) {
        if(level_str.equals(LEVEL[i])) {
            level = i;
        }
        }
        level_str = null;
    }
    return level;
    }

    public String getID() {
    if(id == null) {
        StringBuffer id_buffer = new StringBuffer();
        // Write level information, if any.
        int level = getLevel();
        if(0 <= level && level < 3) {
        id_buffer.append(LEVEL[level]);
        id_buffer.append(StaticStrings.COLON_CHARACTER);
        }
        // Write data information. Retrieve each of the content sources and add them in a comma separated list.
        ArrayList sources = getSources();
        int sources_size = sources.size();
        for(int i = 0; i < sources_size; i++) {
        Object source_object = sources.get(i);
        if(source_object instanceof ElementWrapper) {
            id_buffer.append(((ElementWrapper)source_object).getName());
        }
        else {
            id_buffer.append(source_object.toString());
        }
        id_buffer.append(StaticStrings.COMMA_CHARACTER);
        }
        sources = null;
        id = id_buffer.substring(0, id_buffer.length() - 1);
    }
    return id;
    }

    /** Retrieve the sources of this index.
     * @return the sources as an ArrayList
     */
    public ArrayList getSources() {
    if(sources == null) {
        sources = new ArrayList();
        NodeList content_elements = element.getElementsByTagName(CollectionConfiguration.CONTENT_ELEMENT);
        int content_elements_length = content_elements.getLength();
        for(int i = 0; i < content_elements_length; i++) {
        Element content_element = (Element) content_elements.item(i);
        sources.add(content_element.getAttribute(CollectionConfiguration.NAME_ATTRIBUTE));
        }
        content_elements = null;
        Collections.sort(sources);
    }
    return sources;
    }

    public boolean isAssigned() {
    return (element != null && !element.getAttribute(CollectionConfiguration.ASSIGNED_ATTRIBUTE).equals(CollectionConfiguration.FALSE_STR));
    }

    public void setAssigned(boolean assigned) {
    if(element != null) {
        element.setAttribute(CollectionConfiguration.ASSIGNED_ATTRIBUTE, (assigned ? CollectionConfiguration.TRUE_STR : CollectionConfiguration.FALSE_STR));
    }
    }

    public void setElement(Element element) {
    this.element = element;
    this.level = -1;
    this.id = null;
    this.sources = null;
    }

    /** Method to set the level of this index which can only be used for the default index. 
     * @param level the new level as an int
     */
    public void setLevel(int new_level) {
    if(element != null && element.getNodeName().equals(CollectionConfiguration.INDEX_DEFAULT_ELEMENT)) {
        element.setAttribute(CollectionConfiguration.LEVEL_ATTRIBUTE, LEVEL[new_level]);
        this.id = null; // Regenerate ID.
        this.level = new_level;
    }
    else {
        Gatherer.println("Error! Called setLevel() of index other than the default.");
    }
    }

    /** Method to set the sources for this index which can only be used for the default index.
     * @param sources an ArrayList of source names
     */
    public void setSources(ArrayList sources) {
    if(element != null && element.getNodeName().equals(CollectionConfiguration.INDEX_DEFAULT_ELEMENT)) {
        // Erase old sources
        MSMUtils.clear(element);
        // For each entry in the sources array add a new content element.
        int size = sources.size();
        for(int i = 0; i < size; i++) {
        Element content_element = element.getOwnerDocument().createElement(CollectionConfiguration.CONTENT_ELEMENT);
        content_element.setAttribute(CollectionConfiguration.NAME_ATTRIBUTE, (String) sources.get(i));
        element.appendChild(content_element);
        content_element = null;
        }
        this.id = null; // Regenerate ID.
        this.sources = sources;
    }
    else {
        Gatherer.println("Error! Called setSource() of index other than the default.");
    }
    }

    /** Method to turn this object into a string representation ready to be placed in the collection configuration file.
     * @return A <strong>String</strong> containing the information of this class.
     */
    public String toString() {
    String id = getID();
    StringBuffer text = new StringBuffer(id);
    CollectionMeta metadatum = CollectionDesignManager.collectionmeta_manager.getMetadatum(StaticStrings.STOP_CHARACTER + id, false);
    if(metadatum != null) {
        text.append(" \"");
        text.append(metadatum.getValue());
        text.append("\"");
    }
    return text.toString();
    }
}