/*
 *
 * Copyright (C) 1997, 1998 Yuuji ICHISUGI
 *
 * Permission to use, copy, modify and redistribution this software in
 * whole and in part, for evaluation or research purposes and without fee
 * is hereby granted provided this copyright notice.
 * See CopyrightAndLicensing.txt for licensing condition.
 */


/*
 Usage:
	epp -plug-in EmbedCopyright File1.java File2.java ...

 This plug-in embeds copyright message into all classes.
 The message is added to each class as a static final String field.

 The contents of a text file, "Copyright.txt", is used as
a copyright message.


 NOTE:
 Re-definition of the super class's field with the same name
will cause no errors.  It just shadows the super class's field.
 Therefore, embedded field in subclasses will cause no errors.

*/

#epp "Symbol"
#epp "SystemMixin"
#epp "AutoSplitFiles"
#epp "BackQuote"


package EmbedCopyright;
import epp.*;
import java.io.*;


SystemMixin EmbedCopyright {
  class Epp {
    
    extend void initMacroTable() {
      original();
      String str = readCopyrightFile();
      redefineMacro(:classBody,
		    new EmbedCopyrightMacro
		    (((Macro)Macro.macroTable.get(:classBody)),
		     str));
    }
    
    define implement String readCopyrightFile(){
      DataInputStream out;
      try {
	out = new DataInputStream
	  (new BufferedInputStream
	   (new java.io.FileInputStream(copyrightFileName())));
      } catch (IOException e) {
	System.err.println("EmbedCopyright: Warning: The file "+
			   copyrightFileName()+
			   " cound not be opend.");
	return "This is a sample Copyright message.";
      }
      try {
      	return out.readLine();
      } catch (IOException e) {
	throw error("EmbedCopyright: Can not read a line from "+
		    copyrightFileName());
      } finally {
	try {
	  out.close();
	} catch (IOException e) {
	  throw error("EmbedCopyright: Can not close "+
		      copyrightFileName());
	}
      }
    }
    
    define implement String copyrightFileName(){
      return "Copyright.txt";
    }
  }
}

class EmbedCopyrightMacro extends Macro {
  Macro orig;
  String message;
  
  EmbedCopyrightMacro(Macro orig, String message){
    this.orig = orig;
    this.message = message;
  }
  
  public Tree call(Tree tree){
    // NOTE:
    // The dynamic variable :beginningOfClassBody is unbound at here.
    TreeVec tvec = new TreeVec();
    tvec.addA(tree.args());
    tvec.add(
	     `(decl (modifiers (id public) (id static) (id final))
	       (id String)
	       (vardecls
		(varInit (id EmbeddedCopyrightString)
		 ,(new LiteralTree(:string, message)))))
	     );
    return orig.call(tree.modifyArgs(tvec.toArray()));
  }
}