import java.awt.*;
import java.io.*;
import java.lang.*;
class Complete {
// Copyleft Harvey Greenberg, UW hgreen@u.washington.edu Fri Jan 24 09:49 1997
// Error handling is neither complete nor elegant
// calls class Bil
// Makes graphic calls only if arguments are omitted
// Imagine a landscape represented by a lattice, on which the position of
// streams has been calculated by a method such as contributing area times
// slope squared is greater than a threshold.  The river network would seem
// to be incomplete, fading out in flat or divergent areas.  Assuming that
// the streams are continuous, we want to trace the water downhill to complete
// the network.
// The first argument is the root name of a flowdirection bil (see class Bil)
// file.  It follows the old TOPMODEL/ARCINFO convention that 1 = to the right
// (column++), 2 = right and down (column++,row++), 4 = down ... 128 = right
// and up.  The second argument is the root name of a byte file in which
// river cells are integers between 1 and 127, and the background is 0.
// If the arguments are omitted, you can use a widget to enter them.
// You may click on the hdr or bil file; the extension gets stripped off.
// The output file is a representation of the complete river network, with
// all cells coded 1.  The original river file is overwritten.

    public static void main (String args[])  throws IOException {
	Bil valgrd,dirgrd,rivgrd;
	int idot,nrows,ncols,nrowsm1,ncolsm1,fixes,dir,r=0,c=0;
	String flowroot, rivroot, fullname,fullname2;
	Frame window = new Frame();
	System.out.println("Complete: version 1.0");
	if (args.length < 1){
	    System.out.println("Select a direction bil file: ");
	    FileDialog fd = new FileDialog(window,"Direction file");
	    fd.show();
	    fullname = fd.getDirectory() + fd.getFile();
	    idot = fullname.lastIndexOf(".");
	    flowroot = fullname.substring(0,idot);
	}
	else
	    flowroot = args[0];
	if (args.length < 2){
	    System.out.println("Select a stream bil file (IT WILL BE OVERWRITTEN): ");
	    FileDialog fd2 = new FileDialog(window,"Stream file");
	    fd2.show();
	    fullname2 = fd2.getDirectory() + fd2.getFile();
	    idot = fullname2.lastIndexOf(".");
	    rivroot = fullname2.substring(0,idot);
	}
	else
	    rivroot = args[1];
	dirgrd = new Bil(flowroot);
	rivgrd = new Bil(rivroot);
	nrows = dirgrd.nr;
	ncols = dirgrd.nc;
	if(nrows != rivgrd.nr || (ncols != rivgrd.nc)){
	  System.out.println("ERROR: rows and columns do not match: " + nrows + "×" + ncols + " v. " + rivgrd.nr + "×" + rivgrd.nc);
	  return;
	}
	if(dirgrd.nb != 8 || rivgrd.nb != 8){
	  System.out.println("ERROR: This class reqires that both input files be byte arrays");
	  return; 
	}
	nrowsm1 = nrows - 1;
	ncolsm1 = ncols - 1;

	for(int i=0;i < nrows;i++){
	    for(int j=0;j < ncols;j++){
	      if (rivgrd.barray[i][j] > 0){	// We assume all river cells are > 0
		r = i;
		c = j;
		tracy: while(true){	//Trace to sink or edge of grid
		  dir = dirgrd.barray[r][c];	// We assume topmodel/arcinfo coding.
		  rivgrd.barray[r][c] = -1;	// Flag as done.
		  switch(dir){
		  case 1: // check grid bounds and increment column
		    if(c++ == ncolsm1) break tracy;
		   break;
		  case 2:
		    if(c++ == ncolsm1 | r++ == nrowsm1) break tracy;
		   break;
		  case 4:
		    if(r++ == nrowsm1) break tracy;
		   break;
		  case 8:
		    if(c-- == 0 | r++ == nrowsm1) break tracy;
		   break;
		  case 16:
		    if(c-- == 0 ) break tracy;
		   break;
		  case 32:
		    if(c-- == 0 | r-- == 0) break tracy;
		   break;
		  case 64:
		    if( r-- == 0) break tracy;
		   break;
		  case -128:  // arcinfo unsigned value is read as signed
		    if(c++ == ncolsm1 | r-- == 0) break tracy;
		   break;
		  default:
		    System.out.println("flat: " + r + "," + c);
		  }
		  if(rivgrd.barray[r][c] == -1) break;
	        }	// while tracing from one source
	      }		// if a cell to trace from
	    }	// i
	}	// j
	for(int i=0;i < nrows;i++){
	    for(int j=0;j < ncols;j++){
		if(rivgrd.barray[i][j] == -1)
		  rivgrd.barray[i][j] = 1; // 1 is a nicer flag than -1
	    }	// i
	}	// j
	rivgrd.write(rivroot + ".bil");	// overwrite the bil file
    }	// main
}	// class Complete