/*
 * Copyright (c) 2009-2020, Peter Abeles. All Rights Reserved.
 *
 * This file is part of Efficient Java Matrix Library (EJML).
 *
 * Licensed 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.ejml.dense.row.decompose;

import org.ejml.data.ZMatrixRMaj;
import org.ejml.dense.row.MatrixFeatures_ZDRM;
import org.ejml.dense.row.RandomMatrices_ZDRM;
import org.ejml.interfaces.decomposition.DecompositionInterface;

import java.util.Random;

import static org.junit.jupiter.api.Assertions.assertTrue;


/**
 * @author Peter Abeles
 */
public class CheckDecompositionInterface_ZDRM {

    /**
     * Performs a decomposition and makes sure the input matrix is not modified.
     */
    public static boolean safeDecomposition(DecompositionInterface<ZMatrixRMaj> decomp , ZMatrixRMaj A ) {

        ZMatrixRMaj A_orig = decomp.inputModified() ? A.copy() : A;

        return decomp.decompose(A_orig);
    }


    /**
     * Checks to see if the matrix is or is not modified as according to the modified
     * flag.
     *
     * @param decomp
     */
    public static void checkModifiedInput( DecompositionInterface<ZMatrixRMaj> decomp ) {
        ZMatrixRMaj A = RandomMatrices_ZDRM.hermitianPosDef(4, new Random(0x434));
        ZMatrixRMaj A_orig = A.copy();

        assertTrue(decomp.decompose(A));

        boolean modified = !MatrixFeatures_ZDRM.isEquals(A, A_orig);

        assertTrue(decomp.inputModified()==modified,modified+" "+decomp.inputModified());
    }
}
