/*
 * Copyright IBM Corp. and others 2001
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] https://openjdk.org/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0 OR GPL-2.0-only WITH OpenJDK-assembly-exception-1.0
 */
package com.ibm.j9ddr.vm29.tools.ddrinteractive.commands;

import java.io.PrintStream;
import com.ibm.j9ddr.CorruptDataException;
import com.ibm.j9ddr.tools.ddrinteractive.Command;
import com.ibm.j9ddr.tools.ddrinteractive.CommandUtils;
import com.ibm.j9ddr.tools.ddrinteractive.Context;
import com.ibm.j9ddr.tools.ddrinteractive.DDRInteractiveCommandException;
import com.ibm.j9ddr.vm29.j9.ObjectModel;
import com.ibm.j9ddr.vm29.pointer.generated.J9BuildFlags;
import com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer;
import com.ibm.j9ddr.vm29.pointer.generated.J9ObjectPointer;
import com.ibm.j9ddr.vm29.pointer.helper.J9ClassHelper;
import com.ibm.j9ddr.vm29.pointer.helper.J9ObjectHelper;
import com.ibm.j9ddr.vm29.pointer.helper.ValueTypeHelper;

public class HashCodeCommand extends Command {

	public HashCodeCommand()
	{
		addCommand("hashcode", "<address>", "prints out the Object.hashcode() for an object");
	}

	public void run(String command, String[] args, Context context,	final PrintStream out) throws DDRInteractiveCommandException 
	{
		if (args.length != 1) {
			throw new DDRInteractiveCommandException("This debug extension needs a single address argument: !hashcode <object addr>");
		}
		long address = CommandUtils.parsePointer(args[0], J9BuildFlags.J9VM_ENV_DATA64);
		final J9ObjectPointer objectPointer = J9ObjectPointer.cast(address);

		try {
			J9ClassPointer clazz = J9ObjectHelper.clazz(objectPointer);
			if (!J9ClassHelper.hasValidEyeCatcher(clazz)) {
				throw new DDRInteractiveCommandException("object class is not valid (eyecatcher is not 0x99669966)");
			}
			if (ValueTypeHelper.getValueTypeHelper().isJ9ClassAValueType(clazz)) {
				throw new DDRInteractiveCommandException("cannot calculate the hashcode of a value type object");
			}
		} catch (CorruptDataException cde) {
			throw new DDRInteractiveCommandException("memory fault de-referencing address argument", cde);
		}

		try {
			out.println(ObjectModel.getObjectHashCode(objectPointer).getHexValue());
		} catch (CorruptDataException cde) {
			throw new DDRInteractiveCommandException("error calculating hashcode", cde);
		}

	}
}
