/**
 * 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.branch;

import org.evosuite.coverage.ControlFlowDistance;
import org.evosuite.testcase.ExecutableChromosome;
import org.evosuite.testcase.TestChromosome;
import org.evosuite.testcase.TestFitnessFunction;
import org.evosuite.testcase.execution.ExecutionResult;
import org.evosuite.testcase.execution.MethodCall;

/**
 * Fitness function for a single test on a single branch
 * 
 * @author Gordon Fraser
 */
public class BranchCoverageTestFitness extends TestFitnessFunction {

	private static final long serialVersionUID = -6310967747257242580L;

	/** Target branch */
	private final BranchCoverageGoal goal;

	/**
	 * Constructor - fitness is specific to a branch
	 * 
	 * @param goal
	 *            a {@link org.evosuite.coverage.branch.BranchCoverageGoal}
	 *            object.
	 */
	public BranchCoverageTestFitness(BranchCoverageGoal goal) throws IllegalArgumentException{
		if(goal == null){
			throw new IllegalArgumentException("goal cannot be null");
		}
		this.goal = goal;
	}

	/**
	 * <p>
	 * getBranch
	 * </p>
	 * 
	 * @return a {@link org.evosuite.coverage.branch.Branch} object.
	 */
	public Branch getBranch() {
		return goal.getBranch();
	}

	public boolean getValue() {
		return goal.getValue();
	}

	public BranchCoverageGoal getBranchGoal() {
		return goal;
	}

	/**
	 * <p>
	 * getClassName
	 * </p>
	 * 
	 * @return a {@link java.lang.String} object.
	 */
	public String getClassName() {
		return goal.getClassName();
	}

	/**
	 * <p>
	 * getMethod
	 * </p>
	 * 
	 * @return a {@link java.lang.String} object.
	 */
	public String getMethod() {
		return goal.getMethodName();
	}

	/**
	 * <p>
	 * getBranchExpressionValue
	 * </p>
	 * 
	 * @return a boolean.
	 */
	public boolean getBranchExpressionValue() {
		return goal.getValue();
	}

	/**
	 * <p>
	 * getUnfitness
	 * </p>
	 * 
	 * @param individual
	 *            a {@link org.evosuite.testcase.ExecutableChromosome} object.
	 * @param result
	 *            a {@link org.evosuite.testcase.execution.ExecutionResult} object.
	 * @return a double.
	 */
	public double getUnfitness(ExecutableChromosome individual, ExecutionResult result) {

		double sum = 0.0;
		boolean methodExecuted = false;

		for (MethodCall call : result.getTrace().getMethodCalls()) {
			if (call.className.equals(goal.getClassName())
			        && call.methodName.equals(goal.getMethodName())) {
				methodExecuted = true;
				if (goal.getBranch() != null) {
					for (int i = 0; i < call.branchTrace.size(); i++) {
						if (call.branchTrace.get(i) == goal.getBranch().getInstruction().getInstructionId()) {
							if (goal.getValue())
								sum += call.falseDistanceTrace.get(i);
							else
								sum += call.trueDistanceTrace.get(i);
						}
					}
				}
			}
		}

		if (goal.getBranch() == null) {
			// logger.info("Branch is null? " + goal.branch);
			if (goal.getValue())
				sum = methodExecuted ? 1.0 : 0.0;
			else
				sum = methodExecuted ? 0.0 : 1.0;

		}

		return sum;
	}

	/**
	 * {@inheritDoc}
	 * 
	 * Calculate approach level + branch distance
	 */
	@Override
	public double getFitness(TestChromosome individual, ExecutionResult result) {
		ControlFlowDistance distance = goal.getDistance(result);

		double fitness = distance.getResultingBranchFitness();

		if(logger.isDebugEnabled()) {
			logger.debug("Goal at line "+goal.getLineNumber()+": approach level = " + distance.getApproachLevel()
					+ " / branch distance = " + distance.getBranchDistance() + ", fitness = " + fitness);
		}
		updateIndividual(this, individual, fitness);

		return fitness;
	}


	/** {@inheritDoc} */
	@Override
	public String toString() {
		return goal.toString();
	}

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

	/** {@inheritDoc} */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		BranchCoverageTestFitness other = (BranchCoverageTestFitness) obj;
		if (goal == null) {
			if (other.goal != null)
				return false;
		} else if (!goal.equals(other.goal))
			return false;
		return true;
	}

	/* (non-Javadoc)
	 * @see org.evosuite.testcase.TestFitnessFunction#compareTo(org.evosuite.testcase.TestFitnessFunction)
	 */
	@Override
	public int compareTo(TestFitnessFunction other) {
		if (other instanceof BranchCoverageTestFitness) {
			BranchCoverageTestFitness otherBranchFitness = (BranchCoverageTestFitness) other;
			return goal.compareTo(otherBranchFitness.goal);
		}
		return compareClassName(other);
	}

	/* (non-Javadoc)
	 * @see org.evosuite.testcase.TestFitnessFunction#getTargetClass()
	 */
	@Override
	public String getTargetClass() {
		return getClassName();
	}

	/* (non-Javadoc)
	 * @see org.evosuite.testcase.TestFitnessFunction#getTargetMethod()
	 */
	@Override
	public String getTargetMethod() {
		return getMethod();
	}

}