package nettext.document;

import java.util.List;
import java.util.Vector;

/**
 * Class DocumentList will contain a list of all documents on the server.
 *
 * <PRE>
 * Revision History:
 *     v1.0 (Feb. 15, 2004) - Created the DocumentList class
 * </PRE>
 *
 * @author <A HREF="mailto:gtg563g@mail.gatech.edu">Daniyar Zhanbekov</A>
 * @version Version 1.0, Feb. 15, 2004
 */
public class DocumentList {

  /**
   * This is the list of all documents.
   */
  private List documents;

  /**
   * Creates a new <code>DocumentList</code> instance.
   */
  public DocumentList() {
    documents = new Vector();
  }

  /**
   * Goes through the list of already existing docs and if the
   * doc with the same docId already exists, does not add this
   * new doc to the list, and returns false. If no doc with the
   * same docId already exists, then adds this new doc to the
   * list and returns true.
   *
   * @param doc a <code>Document</code> value
   * @return a <code>boolean</code> value
   */
  public final boolean addDocument(final Document doc) {

    if (size() == 0) {
      documents.add(doc);
      return true;
    }

    for (int i = 0; i < size(); i++) {
      if (((Document) documents.get(i)).getDocumentId()
          == doc.getDocumentId()) {
        return false;
      }
    }
    documents.add(doc);
    return true;
  }

  /**
   * Returns the object corresponding to the document, whose name is
   * passed in.
   *
   * @param name of a doca <code>String</code> value
   * @return a <code>Document</code> value
   */
  public final Document getDocument(final String name) {
    DocumentListIterator listIter = new DocumentListIterator(this);

    while (listIter.hasNext()) {
      Document current = listIter.next();
      if (current.getDocumentName().equals(name)) {
        return current;
      }
    }

    return null;
  }

  /**
   * Returns the object corresponding to the doc, whose docId is
   * passed in.
   *
   * @param id a <code>int</code> value
   * @return a <code>Document</code> value
   */
  public final Document getDocument(final int id) {
    DocumentListIterator listIter = new DocumentListIterator(this);

    while (listIter.hasNext()) {
      Document current = listIter.next();
      if (current.getDocumentId() == id) {
        return current;
      }
    }

    return null;
  }

  /**
   * Simply removes all the docs from the list. Doesn't notify
   * anybody or anything, just calls clear on the doc vector.
   */
  public final void clear() {
    documents.clear();
  }

  /**
   * Returns a Document list iterator that points to the first element
   * of the vector.
   *
   * @return a <code>DocumentListIterator</code> value
   */
  public final DocumentListIterator getIterator() {
    return new DocumentListIterator(this);
  }

  /**
   * Tests if there are no docs.
   *
   * @return a <code>boolean</code> value
   */
  public final boolean isEmpty() {
    return documents.isEmpty();
  }

  /**
   * Removes the doc passed in from the list if it is present
   * there.
   *
   * @param doc a <code>Document</code> value
   */
  public final void removeDocument(final Document doc) {
    int index = documents.indexOf(doc);

    if (index >= 0) {
      documents.remove(index);
    }

  }

  /**
   * Returns the number of docs currently available.
   *
   * @return an <code>int</code> value
   */
  public final int size() {
    return documents.size();
  }

  /**
   * Returns the doc at the specified index in the vector.
   *
   * @param index an <code>int</code> value
   * @return a <code>Document</code> value
   */
  protected final Document elementAt(final int index) {
    return (Document) documents.get(index);
  }
}