Arakne / Araknemu

 * This file is part of Araknemu.

 *

 * Araknemu 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 of the License, or

 * (at your option) any later version.

 *

 * Araknemu 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 General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with Araknemu.  If not, see <https://www.gnu.org/licenses/>.

 *

 * Copyright (c) 2017-2020 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.game.monster;

import fr.arakne.utils.value.Interval;

import fr.arakne.utils.value.helper.RandomUtil;

import java.util.List;

import java.util.NoSuchElementException;

import java.util.stream.Collectors;

/**

 * Set of grades for a monster template

 */

public final class GradeSet {

    private static final RandomUtil RANDOM = RandomUtil.createShared();

    private final List<Monster> grades;

    GradeSet(List<Monster> grades) {

        this.grades = grades;

    }

    /**

     * Get all available grades

     * The grades are sorted by level (lower to higher level)

     */

    public List<Monster> all() {

        return grades;

    }

    /**

     * Get one grade from the GradeSet

     * @param i The grade to get from 1 to 6

     */

    /**

     * Get all grades that contained into the given level interval

     * The interval is inclusive (min <= grade level <= max)

     *

     * If the interval is larger than grade levels interval, all grades are returned

     * If the interval is disjoint with grade levels, an empty list is returned

     */

    public List<Monster> in(Interval levels) {

        // All levels are requested

        if (levels.min() == 1 && levels.max() == Integer.MAX_VALUE) {

            return grades;

        }

        return grades.stream()

            .filter(monster -> levels.contains(monster.level()))

            .collect(Collectors.toList())

        ;

    }

    /**

     * Get one random grade extracted from matching grades into levels interval (including)

     *

     * @see GradeSet#in(Interval)

     *

     * @throws NoSuchElementException When levels interval is disjoint with grades levels

     */

    public Monster random(Interval levels) {

        final List<Monster> matching = in(levels);

        switch (matching.size()) {

            case 0:

                throw new NoSuchElementException("Cannot found any valid grade for monster " + grades.get(0).id());

            case 1:

                return matching.get(0);

            default:

                return RANDOM.of(matching);

        }

    }

}