package org.paneris.bibliomania.fti;
   
   import java.util.Enumeration;
   import java.util.Vector;
   
   import org.melati.util.PagedEnumeration;
   
   import com.sleepycat.db.DatabaseException;
   
  public class HitTextsEnumeration implements PagedEnumeration {
    private ContextSearchResults results;
    private int pageStart, pageSize, requestedPageSize;
    private boolean totalCountIsMinimum;
    private Enumeration us;
  
    public HitTextsEnumeration(
      ContextSearchResults resultsP,
      long startTextID,
      long limitTextID,
      int pageStart,
      int requestedPageSize,
      int hitsPerText)
      throws FTIException {
      try {
        this.results = resultsP;
        this.pageStart = pageStart = Math.max(pageStart, 1);
        this.requestedPageSize = requestedPageSize;
  
        results.gotoText(startTextID);
  
        int areaCount = 0, areasInThisText = 0;
        while (areaCount + 1 < pageStart
          && results.currentTextID() != -1
          && results.currentTextID() < limitTextID) {
          if (results.nextArea() == null || areasInThisText >= hitsPerText) {
            if (results.currentTextID() != -1)
              results.gotoText(results.currentTextID() + 1);
            areasInThisText = 0;
          } else {
            ++areaCount;
            ++areasInThisText;
          }
        }
  
        Vector texts = new Vector();
        int a;
        for (a = 0;
          a < requestedPageSize
            && results.currentTextID() != -1
            && results.currentTextID() < limitTextID;
          ) {
  
          // Just make sure the text exists---we let old indexings hang around
          // rather than expend effort deleting them
  
          if (results.currentText() != null) {
            HitText text =
              new HitText(
                results,
                Math.min(requestedPageSize - a, hitsPerText - areasInThisText));
            areasInThisText = 0;
            texts.addElement(text);
            a += text.areas;
            if (results.currentTextID() != -1)
              results.gotoText(results.currentTextID() + 1);
          }
        }
  
        totalCountIsMinimum = a == requestedPageSize;
        pageSize = a;
  
        us = texts.elements();
      } catch (DatabaseException e) {
        throw new FTIException(e);
      }
    }
  
    // 
    // -------------
    //  Enumeration
    // -------------
    // 
  
    public boolean hasMoreElements() {
      return us.hasMoreElements();
    }
  
    public Object nextElement() {
      return us.nextElement();
    }
  
    // 
    // -----------------
    //  PageEnumeration
    // -----------------
    // 
  
    public int getPageStart() {
      return pageStart;
   }
 
   public int getPageSize() {
     return pageSize;
   }
 
   public int getPageEnd() {
     return pageStart + pageSize - 1;
   }
 
   public int getTotalCount() {
     return getPageEnd();
   }
 
   public boolean getTotalCountIsMinimum() {
     return totalCountIsMinimum;
   }
 
   public Integer getPrevPageStart() {
     int it = pageStart - requestedPageSize;
     return it < 0 ? null : new Integer(it);
   }
 
   public Integer getNextPageStart() {
     return totalCountIsMinimum
       ? new Integer(pageStart + requestedPageSize)
       : null;
   }
 
   public int getCurrentPosition() {
     throw new RuntimeException("TODO No one else has ever called this method." +
                                " Do you really want to start now?");
     
   }
 
   public int getNextPosition() {
     throw new RuntimeException("TODO No one else has ever called this method." +
                                " Do you really want to start now?");
     
   }
 
   public Vector getPages() {
     throw new RuntimeException("TODO No one else has ever called this method." +
                                " Do you really want to start now?");
     
   }
 
   public boolean nextElementOnThisPage() {
     throw new RuntimeException("TODO No one else has ever called this method." +
                                " Do you really want to start now?");
     
   }
 }