/**
 * Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
 * contributors
 *
 * This file is part of EvoSuite.
 *
 * EvoSuite is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3.0 of the License, or
 * (at your option) any later version.
 *
 * EvoSuite is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with EvoSuite. If not, see <http://www.gnu.org/licenses/>.
 */
package org.evosuite.coverage.dataflow.analysis;

import org.evosuite.graphs.ccfg.CCFGMethodCallNode;
import org.evosuite.graphs.cfg.BytecodeInstruction;


/**
 * Represents a single invocation of a method during the Inter-Method pair
 * search.
 * 
 * This class is used to keep track of the current call stack during the
 * search and to differentiate different method calls to the same method.
 * 
 * @author Andre Mis
 */
public class MethodCall {
	private static int invocations = 0;
	private final CCFGMethodCallNode methodCall;
	private final int invocationNumber;
	private final String calledMethod;

	public MethodCall(CCFGMethodCallNode methodCall, String calledMethod) {
		this.methodCall = methodCall;
		invocations++;
		this.invocationNumber = invocations;
		this.calledMethod = calledMethod;
	}

	public boolean isInitialMethodCall() {
		return methodCall == null;
	}

	public boolean isMethodCallFor(BytecodeInstruction callInstruction) {
		if (methodCall == null)
			return callInstruction == null;
		return methodCall.getCallInstruction().equals(callInstruction);
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + invocationNumber;
		result = prime * result
				+ ((methodCall == null) ? 0 : methodCall.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		MethodCall other = (MethodCall) obj;
		if (invocationNumber != other.invocationNumber)
			return false;
		if (methodCall == null) {
			if (other.methodCall != null)
				return false;
		} else if (!methodCall.equals(other.methodCall))
			return false;
		return true;
	}

	public String toString() {
		if (methodCall == null)
			return "initCall for " + calledMethod + " " + invocationNumber;
		return methodCall.getCalledMethod() + " " + invocationNumber;
	}

	public String getCalledMethodName() {
		return calledMethod;
	}

	public static MethodCall constructForCallNode(
			CCFGMethodCallNode callNode) {
		if (callNode == null)
			throw new IllegalArgumentException("given call node was null");
		return new MethodCall(callNode, callNode.getCalledMethod());
	}
}