/* Software Name : AsmDex
 * Version : 1.0
 *
 * Copyright © 2012 France Télécom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.ow2.asmdex.instruction;

import org.ow2.asmdex.lowLevelUtils.ByteVector;
import org.ow2.asmdex.structureCommon.Label;
import org.ow2.asmdex.structureWriter.ConstantPool;

/**
 * A Packed-Switch Pseudo-Instruction. It should use a 4-byte alignment but it is NOT
 * managed here.
 * 
 * @author Julien Névo
 */
public class PseudoInstructionPackedSwitch extends Instruction implements IPseudoInstruction {

	/**
	 * The opcode of this Pseudo Instruction.
	 */
	private final static int PACKED_SWITCH_OPCODE = 0x100;
	
	/**
	 * The first (lowest) key of the Switch.
	 */
	private int firstKey;
	
	/**
	 * The targets for each Case.
	 */
	private Label[] targets;
	
	/**
	 * Reference to the Packed Switch Instruction.
	 */
	private IOffsetInstruction instructionPackedSwitch;
	
	@Override
	public IOffsetInstruction getSourceInstruction() {
		return instructionPackedSwitch;
	}
	
	/**
	 * Constructor of the Packed Switch Pseudo Instruction.
	 * @param firstKey the first (lowest) key of the Switch.
	 * @param targets the targets for each Case.
	 * @param instructionPackedSwitch reference to the Packed Switch Instruction.
	 */
	public PseudoInstructionPackedSwitch(int firstKey, Label[] targets, IOffsetInstruction instructionPackedSwitch) {
		super(PACKED_SWITCH_OPCODE);
		this.firstKey = firstKey;
		this.targets = targets;
		this.instructionPackedSwitch = instructionPackedSwitch; 
	}

	@Override
	public int getSize() {
		return targets.length * 4 + 2 + 2 + 4; // Additions for the Opcode (2), size (2) and first Key (4).
	}

//	@Override
//	public int[] getUsedRegisters() {
//		return null;
//	}

//	@Override
//	public int getNbEncodedRegisters() {
//		return 0;
//	}

	@Override
	public void write(ByteVector out, ConstantPool constantPool) {
		out.putShort(PACKED_SWITCH_OPCODE);
		int size = targets.length;
		out.putShort(size);
		out.putInt(firstKey);
		for (int i = 0; i < size; i++) {
			out.putInt((targets[i].getOffset() - instructionPackedSwitch.getInstructionOffset()) / 2);
		}
	}
}