/*
 * Copyright IBM Corp. and others 2018
 *
 * 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.DataType;
import com.ibm.j9ddr.vm29.j9.HashTable;
import com.ibm.j9ddr.vm29.j9.ModuleHashTable;
import com.ibm.j9ddr.vm29.j9.SlotIterator;
import com.ibm.j9ddr.vm29.pointer.generated.J9HashTablePointer;
import com.ibm.j9ddr.vm29.pointer.generated.J9JavaVMPointer;
import com.ibm.j9ddr.vm29.pointer.generated.J9ModulePointer;
import com.ibm.j9ddr.vm29.pointer.helper.J9RASHelper;
import com.ibm.j9ddr.vm29.tools.ddrinteractive.JavaVersionHelper;
import com.ibm.j9ddr.vm29.tools.ddrinteractive.ModularityHelper;

/**
 * DumpModuleReads command displays all modules that the target module reads
 * 
 * Example:
 * !dumpmodulereads 0x00000130550C7E88
 * Example output: 
 * !j9module 0x000001305F46DB38
 * !j9module 0x00000130550DBB58
 * !j9module 0x000001305F469EA8
 * .....(A list of every module read by the target module)
 */
public class DumpModuleReadsCommand extends Command{

	public DumpModuleReadsCommand()
	{
		addCommand("dumpmodulereads", "<targetModuleAddress>", "display all modules read by the target module");
	}

	public void run(String command, String[] args, Context context, PrintStream out) throws DDRInteractiveCommandException {
		if (args.length != 1) {
			CommandUtils.dbgPrint(out, "Usage: !dumpmodulereads <targetModuleAddress>\n");
			return;
		}
		try {
			J9JavaVMPointer vm = J9RASHelper.getVM(DataType.getJ9RASPointer());
			if (JavaVersionHelper.ensureJava9AndUp(vm, out)) {
				String targetModuleAddress = args[0];
				J9ModulePointer modulePtr = J9ModulePointer.cast(Long.decode(targetModuleAddress));
				J9HashTablePointer readTable = modulePtr.readAccessHashTable();
				HashTable<J9ModulePointer> moduleHashTable = ModuleHashTable.fromJ9HashTable(readTable);
				SlotIterator<J9ModulePointer> slotIterator = moduleHashTable.iterator();
				while (slotIterator.hasNext()) {
					J9ModulePointer readModulePtr = slotIterator.next();
					String moduleName = ModularityHelper.getModuleName(readModulePtr);
					String hexAddress = readModulePtr.getHexAddress();
					out.printf("%-30s !j9module %s%n", moduleName, hexAddress);
				}
			}
		} catch (CorruptDataException e) {
			throw new DDRInteractiveCommandException(e);
		}
	}
}
