/* 
 * JavaLoadCmd.java --
 *
 *	This class implements the built-in "java::load" command in Tcl.
 *
 * Copyright (c) 1997 by Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: JavaLoadCmd.java,v 1.1.1.1 1998/10/14 21:09:14 cvsadmin Exp $
 */

package tcl.lang;
import java.io.File;
import java.io.IOException;
import java.util.*;

class JavaLoadCmd implements Command {

/*
 * List of switches that are legal in the lsort command.
 */

private static final String validOpts[] = {"-classpath"};


/*
 *----------------------------------------------------------------------
 *
 * cmdProc --
 *
 * 	This procedure is invoked to process the "java::load" Tcl command.
 *      See the user documentation for details on what it does.
 *
 * Results:
 *	None
 *
 * Side effects:
 *	The interps result is set or a TclException is thrown.
 *
 *----------------------------------------------------------------------
 */

public void
cmdProc(
    Interp interp,      // the current interpreter.
    TclObject argv[])   // command arguments.
throws
    TclException        // if the package cannot be loaded.
{
    TclClassLoader tclClassLoader;   
    TclObject      classpath; 
    String         packageName; 
    Class          pkgClass;         
    Extension      pkg = null;              
    String         errorMsg;
    boolean 	   validLoad = false;

    if ((argv.length != 2) && (argv.length != 4)) {
	throw new TclNumArgsException(interp, 1, argv,
		"?-classpath arg? packageName");
    }
    
    /*
     * Populate the classpath array with arguments from command line, if 
     * the -classpath option was specified.
     */

    if (argv.length == 4) {
	TclIndex.get(interp, argv[1], validOpts, "switch", 0);
	classpath = argv[2];
	packageName = argv[3].toString();
    } else {
	classpath = null;
	packageName = argv[1].toString();
    }

    errorMsg = "load \"" + packageName + "\" failed: ";

    /*
     * The class loader dosen't want .class at the end, so strip
     * it off if it exists.
     */
    
    if (packageName.endsWith(".class")) {
	packageName = packageName.substring(0,
		packageName.lastIndexOf(".class"));
    }
	
    /*
     * Create a new TclClassLoader.  The classpath and env(TCL_CLASSPATH) 
     * arrays are stored inside the Loader for recursive references
     * to other Classes inside the main Extension class being loaded.
     */

    tclClassLoader = new TclClassLoader(interp, classpath);

    /*
     * Dynamically load the class
     */

    try {
	validLoad = false;
	pkgClass = tclClassLoader.loadClass(packageName, true);
	validLoad = true;
    } catch (ClassNotFoundException e) {
	throw new TclException(interp, "package \"" + packageName +
		"\" not found");
    } catch (ClassFormatError e) {
	throw new TclException(interp, errorMsg +
		"use the fully qualified package name");
    } catch (SecurityException e) {
	throw new TclException(interp, errorMsg + e);
    } finally {
	/* 
	 * If we did not have a valid load, the packageName
	 * must be removed from the static tclClassLoader's 
	 * cache of loaded classes.  If this is not done
	 * any other attempts to load this package will always
	 * use this tclClassLoader and will always fail.
	 */
	
	if (!validLoad) {
	    tclClassLoader.removeCache(packageName);
	}
    }
    
    try {
	/*
	 * Create an instance of the class.  It is important that the class
	 * be casted to a class that was created by the System ClassLoader.
	 * This bridges the super class of the pkgClass with other classes
	 * instantiated by the System ClassLoader.
	 */

	validLoad = false;
	pkg = (Extension)pkgClass.newInstance();

	/*
	 * Initialize the given package. Usually, some new commands will
	 * be created inside the interp.
	 */
	
	pkg.init(interp);
	validLoad = true;
	
    } catch (IllegalAccessException e) {
	throw new TclException (interp, errorMsg +
		"class or initializer is not accessible");
    } catch (InstantiationException e) {
	throw new TclException (interp, errorMsg +
		"object instantiation failure");
    } catch (ClassCastException e) {
	throw new TclException (interp, errorMsg +
		"not a subclass of tcl.lang.Extension");
    } catch (Exception e) {
	throw new TclException (interp, errorMsg +
		"can't find class \"" + e.getMessage() + "\"");
    } finally {
	/* 
	 * If we did not have a valid load, the packageName
	 * must be removed from the static tclClassLoader's 
	 * cache of loaded classes.  If this is not done
	 * any other attempts to load this package will always
	 * use this tclClassLoader and will always fail.
	 */
	
	if (!validLoad) {
	    tclClassLoader.removeCache(packageName);
	}
    }
}
}