/*
 * 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.block;

import com.sk89q.worldedit.WorldEditException;
import com.sk89q.worldedit.extent.Extent;
import com.sk89q.worldedit.function.RegionFunction;
import com.sk89q.worldedit.internal.helper.MCDirections;
import com.sk89q.worldedit.math.BlockVector3;
import com.sk89q.worldedit.math.Vector3;
import com.sk89q.worldedit.math.transform.Transform;
import com.sk89q.worldedit.util.Direction;
import com.sk89q.worldedit.util.Direction.Flag;
import com.sk89q.worldedit.util.nbt.BinaryTag;
import com.sk89q.worldedit.util.nbt.CompoundBinaryTag;
import com.sk89q.worldedit.util.nbt.NumberBinaryTag;
import com.sk89q.worldedit.world.block.BaseBlock;

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

/**
 * Copies blocks from one extent to another.
 */
public class ExtentBlockCopy implements RegionFunction {

    private final Extent source;
    private final Extent destination;
    private final BlockVector3 from;
    private final BlockVector3 to;
    private final Transform transform;

    /**
     * Make a new copy.
     *
     * @param source      the source extent
     * @param from        the source offset
     * @param destination the destination extent
     * @param to          the destination offset
     * @param transform   a transform to apply to positions (after source offset, before destination offset)
     */
    public ExtentBlockCopy(Extent source, BlockVector3 from, Extent destination, BlockVector3 to, Transform transform) {
        checkNotNull(source);
        checkNotNull(from);
        checkNotNull(destination);
        checkNotNull(to);
        checkNotNull(transform);
        this.source = source;
        this.from = from;
        this.destination = destination;
        this.to = to;
        this.transform = transform;
    }

    @Override
    public boolean apply(BlockVector3 position) throws WorldEditException {
        BaseBlock block = source.getFullBlock(position);
        BlockVector3 orig = position.subtract(from);
        BlockVector3 transformed = transform.apply(orig.toVector3()).toBlockPoint();

        // Apply transformations to NBT data if necessary
        block = transformNbtData(block);

        return destination.setBlock(transformed.add(to), block);
    }

    /**
     * Transform NBT data in the given block state and return a new instance
     * if the NBT data needs to be transformed.
     *
     * @param state the existing state
     * @return a new state or the existing one
     */
    private BaseBlock transformNbtData(BaseBlock state) {
        //FAWE start - Replace CompoundTag with CompoundBinaryTag
        CompoundBinaryTag tag = state.getNbt();

        if (tag != null) {
            // Handle blocks which store their rotation in NBT
            BinaryTag rotTag = tag.get("Rot");
            if (rotTag instanceof NumberBinaryTag) {
                int rot = ((NumberBinaryTag) rotTag).intValue();

                Direction direction = MCDirections.fromRotation(rot);

                if (direction != null) {
                    Vector3 vector = transform.apply(direction.toVector()).subtract(transform.apply(Vector3.ZERO)).normalize();
                    Direction newDirection = Direction.findClosest(vector, Flag.CARDINAL | Flag.ORDINAL | Flag.SECONDARY_ORDINAL);

                    if (newDirection != null) {
                        return state.toBaseBlock(
                                tag.putByte("Rot", (byte) MCDirections.toRotation(newDirection))
                                //FAWE end
                        );
                    }
                }
            }
        }

        return state;
    }

}