package rivet.core.labels;

import java.util.Arrays;
import java.util.stream.IntStream;
import java.util.stream.Stream;

import rivet.core.exceptions.SizeMismatchException;
import rivet.core.util.Pair;
import rivet.core.vectorpermutations.Permutations;

public class RIVs {

    public static RIV addRIVs(final RIV rivA, final RIV rivB)
            throws SizeMismatchException {
        return rivA.add(rivB);
    }

    public static double dotProduct(final RIV rivA, final RIV rivB) {
        return getMatchingValStream(rivA, rivB)
                .mapToDouble((valPair) -> valPair.apply((a, b) -> a * b)).sum();
    }

    private static IntStream getMatchingKeyStream(final RIV rivA,
            final RIV rivB) {
        return rivA.keyStream().filter(rivA::contains);
    }

    private static Stream<Pair<Double, Double>> getMatchingValStream(
            final RIV rivA, final RIV rivB) {
        return getMatchingKeyStream(rivA, rivB)
                .mapToObj((i) -> Pair.make(rivA.get(i), rivB.get(i)));
    }

    public static RIV permuteRIV(final RIV riv, final Permutations permutations,
            final int times) {
        return riv.permute(permutations, times);
    }

    public static double similarity(final RIV rivA, final RIV rivB) {
        final double mag = rivA.magnitude() * rivB.magnitude();
        return mag == 0 ? 0 : dotProduct(rivA, rivB) / mag;
    }

    public static RIV sumRIVs(final RIV zeroValue, final RIV... rivs)
            throws SizeMismatchException {
        return sumRIVs(zeroValue, Arrays.stream(rivs));
    }

    public static RIV sumRIVs(final RIV zeroValue, final Stream<RIV> rivs)
            throws SizeMismatchException {
        return rivs.reduce(zeroValue, RIV::destructiveAdd);
    }

}

@@ -1748,10 +1748,38 @@
 %0A    %7D%0A%0A
+    private RIVs() %7B%0A    %7D%0A%0A
 %7D%0A

add private constructor to RIVs