// classes used
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.StreamTokenizer;

import java.util.Vector;

// exceptions thrown
import java.io.FileNotFoundException;
import java.io.IOException;



public class Transform {

    float[] args = null;
    
    public Transform( String filename ) {

	try {

	    FileReader     fRead = new FileReader( filename );
	    BufferedReader bRead = new BufferedReader( fRead );

	    Vector tempArray  = new Vector( );    // temp storage for floats
	    String tempString = null;             // temp storage for line

	    ////////////////////////////////////////
	    // Read in each float until stream is
	    // empty (tempString == null).

	    while ( (tempString = bRead.readLine( )) != null )
		tempArray.insertElementAt( tempString, tempArray.size( ));


	    ////////////////////////////////////////
	    // Create and initialize the float arg-
	    // ument array.

	    args = new float[ tempArray.size( ) ];

	    for ( int i = 0; i < tempArray.size( ); i++ )
		args[i] = Float.valueOf( (String) tempArray.elementAt( i )).
		    floatValue( );

	    
	    ////////////////////////////////////////
	    // Close the file.

	    bRead.close( );


	} catch (FileNotFoundException e) {

	    System.err.println( "File " + filename + " not found." );
	    System.exit( 1 );

	} catch (IOException e) {

	    System.err.println( "Error in file stream." );
	    System.exit( 2 );

	} catch (NumberFormatException e) {

	    System.err.println( "Error in file format (non-float found)." );
	    System.exit( 3 );
	}


	////////////////////////////////////////
	// Wait for commands from the command
	// line.

	waitForCommands();
    }


    public void waitForCommands() {

	boolean needHelp = false;  // yes/no help command requested

	try {

	    InputStreamReader iRead = new InputStreamReader( System.in );
	    BufferedReader    rRead = new BufferedReader( iRead );
	    StreamTokenizer   sRead = new StreamTokenizer( rRead );

      DONE:
	while ( true ) {

	    if (needHelp == false)
		System.out.print( "Command: " );

	    switch ( sRead.nextToken() ) {

	      case StreamTokenizer.TT_WORD :

		  ////////////////////////////////////////
		  // First check to see if any of the com-
		  // mands are driver dependent
		  //
		  //   "display"     display current arg 
		  //                 array
		  //
		  //   "exit"        exit the program
		  //
		  //   "help <com>"  provide help for the 
		  //                 following command
		  //
		  //   "save <file>" save args to file

		  if ( "display".equals( sRead.sval.trim( ) )) {

		      System.out.print( "[ " );
		      for ( int i = 0; i < args.length; i++ )
			  System.out.print( "" + args[i] + " " );
		      System.out.println( " ]");

		      continue;
		  }
		  else if ( "exit".equals( sRead.sval.trim( ) )) {

		      System.out.println( "Quitting . . . " );
		      System.exit( 0 );
		  }
		  else if ( "help".equals( sRead.sval.trim( ) )) {

		      needHelp = true;
		      continue;
		  }
		  else if ( "save".equals( sRead.sval.trim( ) )) {

		      switch( sRead.nextToken( ) ) {

			case StreamTokenizer.TT_WORD :
			    
			    save( sRead.sval );
			    break;

			default                      :
			    
			    System.out.println( "Usage: save <filename>" );
			    break;
		      }

		      continue;
		  }
		  
		  ////////////////////////////////////////
		  // Else assume it is a transformation
		  // command so create the transformation
		  // and perform it's operation.

		  try {
		      Class          c = Class.forName( sRead.sval );
		      Transformation t = (Transformation) c.newInstance();

		      if (needHelp) {
			  
			  t.help( );
			  needHelp = false;
		      }
		      else {

			  t.readArgs( sRead );
			  t.transform( args );
		      }
			
		  } catch (ClassNotFoundException e) {

		      ////////////////////////////////////////
		      // Note that this exception does not force
		      // program termination since it could be
		      // caused by poor typing of commands.

		      System.err.println( "No such transformation or " +
					  "command.");

		  } catch (InstantiationException e) {
		      
		      System.err.println( "Could not create class " + 
					  sRead.sval );
		      System.exit( 4 );

		  } catch (IllegalAccessException e) {

		      System.err.println( "No default constructor found for " 
					  + sRead.sval );
		      System.exit( 5 );

		  }

	      case StreamTokenizer.TT_EOL  :

		  break;

	      case StreamTokenizer.TT_EOF  :

		  break DONE;

	      default                      :

		  System.err.println( "Unrecognized input" );
		  break;
	    }
	}

	} catch (IOException e) {
	    
	    System.err.println( "Error in input stream. ");
	    System.exit( 6 );

	}
    }

    private void save( String filename ) {
	
	try {

	    FileWriter     fWrite = new FileWriter( filename );
	    BufferedWriter bWrite = new BufferedWriter( fWrite );
	    PrintWriter    pWrite = new PrintWriter( bWrite );

	    for (int i = 0; i < args.length; i++ )
		pWrite.println( args[i] );

	    pWrite.close( );

	} catch (IOException e) {

	    System.err.println( "Error in file stream" );
	    System.exit( 7 );
	}
    }


    public static void main( String[] args ) {
	new Transform( args[0] );
    }
			  
}