/* Copyright 2002-2017 CS Systèmes d'Information
 * Licensed to CS Systèmes d'Information (CS) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * CS licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.orekit.estimation.leastsquares;

import org.hipparchus.optim.nonlinear.vector.leastsquares.LeastSquaresProblem;
import org.orekit.errors.OrekitException;
import org.orekit.estimation.measurements.EstimationsProvider;
import org.orekit.orbits.Orbit;
import org.orekit.utils.ParameterDriversList;

/** Observer for {@link BatchLSEstimator batch least squares estimator} iterations.
 * <p>
 * This interface is intended to be implemented by users to monitor
 * the progress of the estimator during estimation.
 * </p>
 * @author Luc Maisonobe
 * @since 8.0
 */
public interface BatchLSObserver {

    /** Notification callback for the end of each evaluation.
     * @param iterationsCount iterations count
     * @param evaluationsCount evaluations count
     * @param orbit current estimated orbit
     * @param estimatedOrbitalParameters estimated orbital parameters
     * @param estimatedPropagatorParameters estimated propagator parameters
     * @param estimatedMeasurementsParameters estimated measurements parameters
     * @param evaluationsProvider provider for measurements evaluations resulting
     * from the current estimated orbit (this is an unmodifiable view of the
     * current evaluations, its content is changed at each iteration)
     * @param lspEvaluation current evaluation of the underlying {@link LeastSquaresProblem
     * least squares problem}
     * @exception OrekitException if some problem occurs (for example evaluationProviders not
     * being able to provide an evaluation)
     */
    void evaluationPerformed(int iterationsCount, int evaluationsCount, Orbit orbit,
                             ParameterDriversList estimatedOrbitalParameters,
                             ParameterDriversList estimatedPropagatorParameters,
                             ParameterDriversList estimatedMeasurementsParameters,
                             EstimationsProvider  evaluationsProvider,
                             LeastSquaresProblem.Evaluation lspEvaluation)
        throws OrekitException;

}