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) 2017-2021 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.game.fight.ai.proxy;

import fr.arakne.utils.maps.CoordinateCell;

import fr.arakne.utils.value.Dimensions;

import fr.quatrevieux.araknemu.game.fight.fighter.PassiveFighter;

import fr.quatrevieux.araknemu.game.fight.map.BattlefieldMap;

import fr.quatrevieux.araknemu.game.fight.map.FightCell;

import java.util.Arrays;

import java.util.Iterator;

import java.util.Optional;

import java.util.function.Consumer;

/**

 * Proxy class for redefine fighters and objects positions

 *

 * Note: this class is immutable

 */

public final class ProxyBattlefield implements BattlefieldMap {

    private final BattlefieldMap map;

    private final ProxyCell[] cells;

    public ProxyBattlefield(BattlefieldMap map) {

        this.map = map;

        this.cells = null;

    }

    private ProxyBattlefield(ProxyBattlefield other) {

        this.map = other.map;

        this.cells = new ProxyCell[other.map.size()];

        for (int i = 0; i < map.size(); ++i) {

            this.cells[i] = other.cells == null

                ? new ProxyCell(map.get(i))

                : new ProxyCell(other.cells[i])

            ;

        }

    }

    @Override

    public int size() {

        return map.size();

    }

    @Override

    public FightCell get(int id) {

        if (cells == null) {

            return map.get(id);

        }

        return cells[id];

    }

    @Override

    public Dimensions dimensions() {

        return map.dimensions();

    }

    @Override

    public Iterator<FightCell> iterator() {

        if (cells == null) {

            return map.iterator();

        }

        return Arrays.<FightCell>asList(cells).iterator();

    }

    /**

     * Modify the map objects

     *

     * Usage:

     * <pre>{@code

     * map.modify(modifier -> {

     *     modifier.free(123).setFighter(125, fighter); // Move "fighter" to cell 125

     * });

     * }</pre>

     *

     * @param configurator Configuration callback

     *

     * @return The new map instance

     */

    public ProxyBattlefield modify(Consumer<Modifier> configurator) {

        final Modifier modifier = new Modifier(this);

        configurator.accept(modifier);

        return modifier.map;

    }

    private final class ProxyCell implements FightCell {

        private final FightCell cell;

        private boolean free = false;

        private PassiveFighter fighter = null;

        private CoordinateCell<FightCell> coordinates = null;

        private ProxyCell(FightCell cell) {

            this.cell = cell;

        }

        private ProxyCell(ProxyCell other) {

            this.cell = other.cell;

            this.free = other.free;

            this.fighter = other.fighter;

        }

        @Override

        public BattlefieldMap map() {

            return ProxyBattlefield.this;

        }

        @Override

        public boolean walkableIgnoreFighter() {

            return cell.walkableIgnoreFighter();

        }

        @Override

        public Optional<PassiveFighter> fighter() {

            if (free) {

                return Optional.empty();

            }

            if (fighter != null) {

                return Optional.of(fighter);

            }

            return cell.fighter();

        }

        @Override

        public void set(PassiveFighter fighter) {

            throw new UnsupportedOperationException("This is a proxy cell");

        }

        @Override

        public void removeFighter() {

            throw new UnsupportedOperationException("This is a proxy cell");

        }

        @Override

        public boolean sightBlocking() {

            if (free && cell.walkableIgnoreFighter()) {

                return false;

            }

            if (fighter != null) {

                return true;

            }

            return cell.sightBlocking();

        }

        @Override

        public int id() {

            return cell.id();

        }

        @Override

        public boolean walkable() {

            if (free) {

                return cell.walkableIgnoreFighter();

            }

            if (fighter != null) {

                return false;

            }

            return cell.walkable();

        }

        @Override

        public CoordinateCell<FightCell> coordinate() {

            if (coordinates == null) {

                coordinates = new CoordinateCell<>(this);

            }

            return coordinates;

        }

    }

    /**

     * Builder class for modifying a proxy map

     */

    public static class Modifier {

        private final ProxyBattlefield map;

        /**

         * Free a cell

         * Calling this method will remove the fighter onb this cell

         *

         * @param cellId Cell to modify

         *

         * @return this instance

         */

        public Modifier free(int cellId) {

            map.cells[cellId].free = true;

            return this;

        }

        /**

         * Get a cell instance

         *

         * @param cellId The cell to get

         */

        public FightCell get(int cellId) {

            return map.cells[cellId];

        }

        /**

         * Set a fighter to the given cell

         *

         * @param cellId Cell to modify

         * @param fighter The fighter to cell

         *

         * @return this instance

         */

        public Modifier setFighter(int cellId, PassiveFighter fighter) {

            map.cells[cellId].free = false;

            map.cells[cellId].fighter = fighter;

            return this;

        }

    }

}