/**
 * Container for an osm node (pre-pocessor version)
 *
 * @author ab
 */
package btools.mapcreator;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;

public class OsmNodeP implements Comparable<OsmNodeP>
{
  public static final int EXTERNAL_BITMASK        = 0x80;
  public static final int FIRSTFORWAY_BITMASK     = 0x40;
  public static final int TRANSFERNODE_BITMASK    = 0x20;
  public static final int WRITEDESC_BITMASK       = 0x10;
  public static final int SKIPDETAILS_BITMASK     = 0x08;
  public static final int NODEDESC_BITMASK        = 0x04;

 /**
   * The latitude
   */
  public int ilat;

 /**
   * The longitude
   */
  public int ilon;


 /**
   * The links to other nodes
   */
  public OsmLinkP firstlink = null;


 /**
   * The elevation
   */
  public short selev;

  public boolean isBorder = false;

  public byte wayAndBits = -1; // use for bridge/tunnel logic


  // interface OsmPos
  public int getILat()
  {
    return ilat;
  }

  public int getILon()
  {
    return ilon;
  }

  public short getSElev()
  {
    // if all bridge or all tunnel, elevation=no-data
    return (wayAndBits & 24) == 0 ? selev : Short.MIN_VALUE;
  }

  public double getElev()
  {
    return selev / 4.;
  }



   public void addLink( OsmLinkP link )
   {
     if ( firstlink != null ) link.next = firstlink;
     firstlink = link;
   }

   public long getNodeDecsription()
   {
     return 0L;
   }

   public void writeNodeData( DataOutputStream os ) throws IOException
   {
     int lonIdx = ilon/62500;
     int latIdx = ilat/62500;

     // buffer the body to first calc size
     ByteArrayOutputStream bos = new ByteArrayOutputStream( );
     DataOutputStream os2 = new DataOutputStream( bos );

     os2.writeShort( getSElev() );

     // hack: write node-desc as link tag (copy cycleway-bits)
     long nodeDescription = getNodeDecsription();

     for( OsmLinkP link0 = firstlink; link0 != null; link0 = link0.next )
     {
       OsmLinkP link = link0;
       OsmNodeP origin = this;
       int skipDetailBit = link0.counterLinkWritten() ? SKIPDETAILS_BITMASK : 0;

       // first pass just to see if that link is consistent
       while( link != null )
       {
         OsmNodeP target = link.targetNode;
         if ( !target.isTransferNode() )
         {
           break;
         }
         // next link is the one (of two), does does'nt point back
         for( link = target.firstlink; link != null; link = link.next )
         {
           if ( link.targetNode != origin ) break;
         }
         origin = target;
       }
       if ( link == null ) continue; // dead end

       if ( skipDetailBit == 0)
       {
         link = link0;
       }
       origin = this;
       long lastDescription = 0;
       while( link != null )
       {
         OsmNodeP target = link.targetNode;
         int tranferbit = target.isTransferNode() ? TRANSFERNODE_BITMASK : 0;
         int writedescbit = link.descriptionBitmap != lastDescription ? WRITEDESC_BITMASK : 0;
         int nodedescbit = nodeDescription != 0L ? NODEDESC_BITMASK : 0;

         if ( skipDetailBit != 0 )
         {
           writedescbit = 0;
         }
         int targetLonIdx = target.ilon/62500;
         int targetLatIdx = target.ilat/62500;

         if ( targetLonIdx == lonIdx && targetLatIdx == latIdx )
         {
           // reduced position for internal target
           os2.writeByte( tranferbit | writedescbit | nodedescbit | skipDetailBit );
           os2.writeShort( (short)(target.ilon - lonIdx*62500 - 31250) );
           os2.writeShort( (short)(target.ilat - latIdx*62500 - 31250) );
         }
         else
         {
           // full position for external target
           os2.writeByte( tranferbit | writedescbit | nodedescbit | skipDetailBit | EXTERNAL_BITMASK );
           os2.writeInt( target.ilon );
           os2.writeInt( target.ilat );
         }
         if ( writedescbit != 0 )
         {
           os2.writeLong( link.descriptionBitmap );
         }
         if ( nodedescbit != 0 )
         {
           os2.writeLong( nodeDescription );
           nodeDescription = 0L;
         }
         lastDescription = link.descriptionBitmap;

         if ( tranferbit == 0)
         {
           target.markLinkWritten( origin );
           break;
         }
         os2.writeShort( target.getSElev() );
         // next link is the one (of two), does does'nt point back
         for( link = target.firstlink; link != null; link = link.next )
         {
           if ( link.targetNode != origin ) break;
         }
         if ( link == null ) throw new RuntimeException( "follow-up link not found for transfer-node!" );
         origin = target;
       }
     }

     // calculate the body size
     int bodySize = bos.size();

     os.writeShort( (short)(ilon - lonIdx*62500 - 31250) );
     os.writeShort( (short)(ilat - latIdx*62500 - 31250) );
     os.writeInt( bodySize );
     bos.writeTo( os );
   }

  public String toString2()
  {
    return (ilon-180000000) + "_" + (ilat-90000000) + "_" + (selev/4);
  }

  public long getIdFromPos()
  {
    return ((long)ilon)<<32 | ilat;
  }

  public boolean isTransferNode()
  {
    return (!isBorder) && _linkCnt() == 2;
  }

  private int _linkCnt()
  {
    int cnt = 0;

    for( OsmLinkP link = firstlink; link != null; link = link.next )
    {
      cnt++;
    }
    return cnt;
  }

   // mark the link to the given node as written,
   // don't want to write the counter-direction
   // in full details
   public void markLinkWritten( OsmNodeP t )
   {
     for( OsmLinkP link = firstlink; link != null; link = link.next )
     {
       if ( link.targetNode == t) link.descriptionBitmap = 0L;
     }
   }

 /**
   * Compares two OsmNodes for position ordering.
   *
   * @return -1,0,1 depending an comparson result
   */
   public int compareTo( OsmNodeP n )
   {
     long id1 = getIdFromPos();
     long id2 = n.getIdFromPos();
     if ( id1 < id2 ) return -1;
     if ( id1 > id2 ) return  1;
     return 0;
   }
}