/*******************************************************************************
 * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *    
 *******************************************************************************/
package org.jacoco.core.internal.flow;

import org.jacoco.core.JaCoCo;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

/**
 * Adapter that creates additional visitor events for probes to be inserted into
 * a method.
 */
public final class MethodProbesAdapter extends MethodVisitor {

	private final MethodProbesVisitor probesVisitor;

	private final IProbeIdGenerator idGenerator;

	/**
	 * Create a new adapter instance.
	 * 
	 * @param probesVisitor
	 *            visitor to delegate to
	 * @param idGenerator
	 *            generator for unique probe ids
	 */
	public MethodProbesAdapter(final MethodProbesVisitor probesVisitor,
			final IProbeIdGenerator idGenerator) {
		super(JaCoCo.ASM_API_VERSION, probesVisitor);
		this.probesVisitor = probesVisitor;
		this.idGenerator = idGenerator;
	}

	@Override
	public void visitLabel(final Label label) {
		if (LabelInfo.isMultiTarget(label) && LabelInfo.isSuccessor(label)) {
			probesVisitor.visitProbe(idGenerator.nextId());
		}
		probesVisitor.visitLabel(label);
	}

	@Override
	public void visitInsn(final int opcode) {
		switch (opcode) {
		case Opcodes.IRETURN:
		case Opcodes.LRETURN:
		case Opcodes.FRETURN:
		case Opcodes.DRETURN:
		case Opcodes.ARETURN:
		case Opcodes.RETURN:
		case Opcodes.ATHROW:
			probesVisitor.visitInsnWithProbe(opcode, idGenerator.nextId());
			break;
		default:
			probesVisitor.visitInsn(opcode);
			break;
		}
	}

	@Override
	public void visitJumpInsn(final int opcode, final Label label) {
		if (LabelInfo.isMultiTarget(label)) {
			probesVisitor.visitJumpInsnWithProbe(opcode, label,
					idGenerator.nextId());
		} else {
			probesVisitor.visitJumpInsn(opcode, label);
		}
	}

	@Override
	public void visitLookupSwitchInsn(final Label dflt, final int[] keys,
			final Label[] labels) {
		if (markLabels(dflt, labels)) {
			probesVisitor.visitLookupSwitchInsnWithProbes(dflt, keys, labels);
		} else {
			probesVisitor.visitLookupSwitchInsn(dflt, keys, labels);
		}
	}

	@Override
	public void visitTableSwitchInsn(final int min, final int max,
			final Label dflt, final Label... labels) {
		if (markLabels(dflt, labels)) {
			probesVisitor
					.visitTableSwitchInsnWithProbes(min, max, dflt, labels);
		} else {
			probesVisitor.visitTableSwitchInsn(min, max, dflt, labels);
		}
	}

	private boolean markLabels(final Label dflt, final Label[] labels) {
		boolean probe = false;
		LabelInfo.resetDone(labels);
		if (LabelInfo.isMultiTarget(dflt)) {
			LabelInfo.setProbeId(dflt, idGenerator.nextId());
			probe = true;
		}
		LabelInfo.setDone(dflt);
		for (final Label l : labels) {
			if (!LabelInfo.isDone(l) && LabelInfo.isMultiTarget(l)) {
				LabelInfo.setProbeId(l, idGenerator.nextId());
				probe = true;
			}
			LabelInfo.setDone(l);
		}
		return probe;
	}

}