package btools.mapcreator;

import java.io.File;

/**
 * NodeCutter does 1 step in map-processing:
 *
 * - cuts the 45*30 node tiles into 5*5 pieces
 *
 * @author ab
 */
public class NodeCutter extends MapCreatorBase
{
  private int lonoffset;
  private int latoffset;

  public static void main(String[] args) throws Exception
  {
    System.out.println("*** NodeCutter: Cut big node-tiles into 5x5 tiles");
    if (args.length != 2)
    {
      System.out.println("usage: java NodeCutter <node-tiles-in> <node-tiles-out>" );
      return;
    }
    new NodeCutter().process( new File( args[0] ), new File( args[1] ) );
  }

  public void process( File nodeTilesIn, File nodeTilesOut ) throws Exception
  {
    this.outTileDir = nodeTilesOut;

    new NodeIterator( this, true ).processDir( nodeTilesIn, ".tlf" );
  }

  @Override
  public void nodeFileStart( File nodefile ) throws Exception
  {
    lonoffset = -1;
    latoffset = -1;
  }

  @Override
  public void nextNode( NodeData n ) throws Exception
  {
    n.writeTo( getOutStreamForTile( getTileIndex( n.ilon, n.ilat ) ) );
  }

  @Override
  public void nodeFileEnd( File nodeFile ) throws Exception
  {
    closeTileOutStreams();
  }

  private int getTileIndex( int ilon, int ilat )
  {
     int lonoff = (ilon / 45000000 ) * 45;
     int latoff = (ilat / 30000000 ) * 30;
     if ( lonoffset == -1 ) lonoffset = lonoff;
     if ( latoffset == -1 ) latoffset = latoff;
     if ( lonoff != lonoffset || latoff != latoffset )
       throw new IllegalArgumentException( "inconsistent node: " + ilon + " " + ilat );

     int lon = (ilon / 5000000) % 9;
     int lat = (ilat / 5000000) % 6;
     if ( lon < 0 || lon > 8 || lat < 0 || lat > 5 ) throw new IllegalArgumentException( "illegal pos: " + ilon + "," + ilat );
     return lon*6 + lat;
  }


  protected String getNameForTile( int tileIndex )
  {
    int lon = (tileIndex / 6 ) * 5 + lonoffset - 180;
    int lat = (tileIndex % 6 ) * 5 + latoffset - 90;
    String slon = lon < 0 ? "W" + (-lon) : "E" + lon;
    String slat = lat < 0 ? "S" + (-lat) : "N" + lat;
    return slon + "_" + slat + ".n5d";
  }

}