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/*
 * The MIT License
 *
 *   Copyright (c) 2016, Mahmoud Ben Hassine ([email protected])
 *
 *   Permission is hereby granted, free of charge, to any person obtaining a copy
 *   of this software and associated documentation files (the "Software"), to deal
 *   in the Software without restriction, including without limitation the rights
 *   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *   copies of the Software, and to permit persons to whom the Software is
 *   furnished to do so, subject to the following conditions:
 *
 *   The above copyright notice and this permission notice shall be included in
 *   all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *   THE SOFTWARE.
 */

package io.github.benas.randombeans.randomizers.collection;

import io.github.benas.randombeans.api.Randomizer;
import lombok.NonNull;

import java.util.HashMap;
import java.util.Map;

import static io.github.benas.randombeans.randomizers.number.ByteRandomizer.aNewByteRandomizer;
import static java.lang.Math.abs;

/**
 * A {@link Randomizer} that generates a {@link Map} with random entries.
 *
 * @param  the type of keys
 * @param  the type of values
 * @author Mahmoud Ben Hassine ([email protected])
 */
public class MapRandomizer implements Randomizer> {

    private final int nbElements;

    private final Randomizer keyRandomizer;

    private final Randomizer valueRandomizer;

    /**
     * Create a new {@link MapRandomizer} with a random number of entries.
     *
     * @param keyRandomizer   the randomizer for keys
     * @param valueRandomizer the randomizer for values
     */
    public MapRandomizer(final Randomizer keyRandomizer, final Randomizer valueRandomizer) {
        this(keyRandomizer, valueRandomizer, abs(aNewByteRandomizer().getRandomValue()));
    }

    /**
     * Create a new {@link MapRandomizer} with a fixed number of entries.
     *
     * @param keyRandomizer   the randomizer for keys
     * @param valueRandomizer the randomizer for values
     * @param nbEntries       the number of entries to generate
     */
    public MapRandomizer(@NonNull final Randomizer keyRandomizer, @NonNull final Randomizer valueRandomizer, final int nbEntries) {
        checkArguments(nbEntries);
        this.keyRandomizer = keyRandomizer;
        this.valueRandomizer = valueRandomizer;
        this.nbElements = nbEntries;
    }

    /**
     * Create a new {@link MapRandomizer} with a random number of entries.
     *
     * @param keyRandomizer   the randomizer for keys
     * @param valueRandomizer the randomizer for values
     */
    public static  MapRandomizer aNewMapRandomizer(final Randomizer keyRandomizer, final Randomizer valueRandomizer) {
        return new MapRandomizer<>(keyRandomizer, valueRandomizer, abs(aNewByteRandomizer().getRandomValue()));
    }

    /**
     * Create a new {@link MapRandomizer} with a fixed number of entries.
     *
     * @param keyRandomizer   the randomizer for keys
     * @param valueRandomizer the randomizer for values
     * @param nbEntries       the number of entries to generate
     */
    public static  MapRandomizer aNewMapRandomizer(final Randomizer keyRandomizer, final Randomizer valueRandomizer, final int nbEntries) {
        return new MapRandomizer<>(keyRandomizer, valueRandomizer, nbEntries);
    }

    @Override
    public Map getRandomValue() {
        Map result = new HashMap<>();
        for (int i = 0; i < nbElements; i++) {
            result.put(keyRandomizer.getRandomValue(), valueRandomizer.getRandomValue());
        }
        return result;
    }

    private void checkArguments(final int nbEntries) {
        if (nbEntries < 1) {
            throw new IllegalArgumentException("The number of entries to generate must be >= 1");
        }
    }

}