/**
 * Set holding pairs of osm nodes
 *
 * @author ab
 */
package btools.mapaccess;

import btools.util.CompactLongMap;

public class OsmNodePairSet
{
  private long[] n1a;
  private long[] n2a;
  private int tempNodes = 0;
  private int maxTempNodes = 0;
  private int npairs = 0;
  private int freezecount = 0;

  public OsmNodePairSet( int maxTempNodeCount )
  {
    maxTempNodes = maxTempNodeCount;
    n1a = new long[maxTempNodes];
    n2a = new long[maxTempNodes];
  }

  private static class OsmNodePair
  {
    public long node2;
    public OsmNodePair next;
  }
  
  private CompactLongMap<OsmNodePair> map;

  public void addTempPair( long n1, long n2 )
  {
    if ( tempNodes < maxTempNodes )
    {
      n1a[tempNodes] = n1;
      n2a[tempNodes] = n2;
      tempNodes++;
    }
  }
  
  public void freezeTempPairs()
  {
    freezecount++;
    for( int i=0; i<tempNodes; i++ )
    {
      addPair( n1a[i], n2a[i] );
    }
    tempNodes = 0;
  }
  
  public void clearTempPairs()
  {
    tempNodes = 0;
  }

  private void addPair( long n1, long n2 )
  {
    if ( map == null )
    {
      map = new CompactLongMap<OsmNodePair>();
    }
    npairs++;
  
    OsmNodePair e = getElement( n1, n2 );
    if ( e == null )
    {
      e = new OsmNodePair();
      e.node2 = n2;

      OsmNodePair e0 = map.get( n1 );
      if ( e0 != null )
      {
        while( e0.next != null )
        {
          e0 = e0.next;
        }
        e0.next = e;
      }
      else
      {
        map.fastPut( n1, e );
      }
    }
  }
  
  public int size()
  {
    return npairs;
  }

  public int tempSize()
  {
    return tempNodes;
  }

  public int getFreezeCount()
  {
    return freezecount;
  }
  
  public boolean hasPair( long n1, long n2 )
  {
    return map != null && ( getElement( n1, n2 ) != null || getElement( n2, n1 ) != null );
  }

  private OsmNodePair getElement( long n1, long n2 )
  {
    OsmNodePair e = map.get( n1 );
    while (e != null)
    {
      if ( e.node2 == n2 )
      {
        return e;
      }
      e = e.next;
    }
    return null;
  }
}