/**
 * 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.assertion;

import java.util.HashSet;
import java.util.Set;

import org.evosuite.Properties;
import org.evosuite.testcase.variable.VariableReference;


/**
 * <p>NullTraceEntry class.</p>
 *
 * @author fraser
 */
public class NullTraceEntry implements OutputTraceEntry {

	private final boolean isNull;

	private final VariableReference var;

	/**
	 * <p>Constructor for NullTraceEntry.</p>
	 *
	 * @param var a {@link org.evosuite.testcase.variable.VariableReference} object.
	 * @param result a boolean.
	 */
	public NullTraceEntry(VariableReference var, boolean result) {
		this.var = var;
		this.isNull = result;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.assertion.OutputTraceEntry#differs(org.evosuite.assertion.OutputTraceEntry)
	 */
	/** {@inheritDoc} */
	@Override
	public boolean differs(OutputTraceEntry other) {
		if (other instanceof NullTraceEntry) {
			NullTraceEntry otherEntry = (NullTraceEntry) other;
			if (var.equals(otherEntry.var) && otherEntry.isNull != isNull)
				return true;

		}
		return false;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.assertion.OutputTraceEntry#getAssertions(org.evosuite.assertion.OutputTraceEntry)
	 */
	/** {@inheritDoc} */
	@Override
	public Set<Assertion> getAssertions(OutputTraceEntry other) {
		Set<Assertion> assertions = new HashSet<Assertion>();

		if (other instanceof NullTraceEntry) {
			NullTraceEntry otherEntry = (NullTraceEntry) other;
			if (var.equals(otherEntry.var) && otherEntry.isNull != isNull) {
				NullAssertion assertion = new NullAssertion();
				assertion.value = isNull;
				assertion.source = var;
				if(Properties.isRegression())
					assertion.setComment("// (Null) Original Value: " + var +" | Regression Value: " + otherEntry.var);
				assertions.add(assertion);
				assert (assertion.isValid());
			}

		}
		return assertions;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.assertion.OutputTraceEntry#getAssertions()
	 */
	/** {@inheritDoc} */
	@Override
	public Set<Assertion> getAssertions() {
		Set<Assertion> assertions = new HashSet<Assertion>();
		NullAssertion assertion = new NullAssertion();
		assertion.value = isNull;
		assertion.source = var;
		assertions.add(assertion);
		assert (assertion.value != null);
		assert (assertion.isValid());
		return assertions;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.assertion.OutputTraceEntry#isDetectedBy(org.evosuite.assertion.Assertion)
	 */
	/** {@inheritDoc} */
	@Override
	public boolean isDetectedBy(Assertion assertion) {
		if (assertion instanceof NullAssertion) {
			NullAssertion ass = (NullAssertion) assertion;
			if (var.equals(ass.source))
				return ((Boolean) ass.value).booleanValue() != isNull;
		}
		return false;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.assertion.OutputTraceEntry#cloneEntry()
	 */
	/** {@inheritDoc} */
	@Override
	public OutputTraceEntry cloneEntry() {
		return new NullTraceEntry(var, isNull);
	}

}