/*
 * WorldEdit, a Minecraft world manipulation toolkit
 * Copyright (C) sk89q <http://www.sk89q.com>
 * Copyright (C) WorldEdit team and contributors
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package com.sk89q.worldedit.function.util;

import com.sk89q.worldedit.WorldEditException;
import com.sk89q.worldedit.function.FlatRegionFunction;
import com.sk89q.worldedit.math.BlockVector2;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Offsets the position parameter by adding a given offset vector.
 */
public class FlatRegionOffset implements FlatRegionFunction {

    private BlockVector2 offset;
    private final FlatRegionFunction function;

    /**
     * Create a new instance.
     *
     * @param offset   the offset
     * @param function the function that is called with the offset position
     */
    public FlatRegionOffset(BlockVector2 offset, FlatRegionFunction function) {
        checkNotNull(function);
        setOffset(offset);
        this.function = function;
    }

    /**
     * Get the offset that is added to the position.
     *
     * @return the offset
     */
    public BlockVector2 getOffset() {
        return offset;
    }

    /**
     * Set the offset that is added to the position.
     *
     * @param offset the offset
     */
    public void setOffset(BlockVector2 offset) {
        checkNotNull(offset);
        this.offset = offset;
    }

    @Override
    public boolean apply(BlockVector2 position) throws WorldEditException {
        return function.apply(position.add(offset));
    }

}
