EnergonRelics/src/main/java/com/thebrokenrail/energonrelics/structure/StructurePart.java

package com.thebrokenrail.energonrelics.structure;

import com.thebrokenrail.energonrelics.util.MissingCaseException;
import net.minecraft.block.BlockState;
import net.minecraft.state.property.Properties;
import net.minecraft.util.BlockMirror;
import net.minecraft.util.BlockRotation;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.Direction;
import net.minecraft.world.World;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public abstract class StructurePart<T> {
    public interface Transformation {
        BlockPos transform(BlockPos pos);
        BlockState transform(BlockState state);
    }

    private final T state;

    protected T getState() {
        return state;
    }

    public StructurePart(T state, List<Transformation> list) {
        this.state = state;
        transformations.addAll(list);
    }

    private final Map<Long, BlockState> blocks = new HashMap<>();

    private final List<Transformation> transformations = new ArrayList<>();

    protected static final Transformation NONE = new Transformation() {
        @Override
        public BlockPos transform(BlockPos pos) {
            return pos;
        }

        @Override
        public BlockState transform(BlockState state) {
            return state;
        }
    };
    protected static final Transformation CLOCKWISE_90 = new Transformation() {
        @Override
        public BlockPos transform(BlockPos pos) {
            return new BlockPos(-pos.getZ(), pos.getY(), pos.getX());
        }

        @Override
        public BlockState transform(BlockState state) {
            return state.rotate(BlockRotation.CLOCKWISE_90);
        }
    };
    protected static final Transformation CLOCKWISE_180 = new Transformation() {
        @Override
        public BlockPos transform(BlockPos pos) {
            return new BlockPos(-pos.getX(), pos.getY(), -pos.getZ());
        }

        @Override
        public BlockState transform(BlockState state) {
            return state.rotate(BlockRotation.CLOCKWISE_180);
        }
    };
    protected static final Transformation COUNTERCLOCKWISE_90 = new Transformation() {
        @Override
        public BlockPos transform(BlockPos pos) {
            return new BlockPos(pos.getZ(), pos.getY(), -pos.getX());
        }

        @Override
        public BlockState transform(BlockState state) {
            return state.rotate(BlockRotation.COUNTERCLOCKWISE_90);
        }
    };
    protected static final Transformation MIRROR_DEPTH = new Transformation() {
        @Override
        public BlockPos transform(BlockPos pos) {
            return new BlockPos(pos.getX(), pos.getY(), -pos.getZ());
        }

        @Override
        public BlockState transform(BlockState state) {
            state = state.mirror(BlockMirror.LEFT_RIGHT);
            if (state.contains(Properties.CHEST_TYPE)) {
                state = state.with(Properties.CHEST_TYPE, state.get(Properties.CHEST_TYPE).getOpposite());
            }
            return state;
        }
    };

    protected abstract void build(StructureContext context);

    private BlockPos transform(BlockPos pos) {
        for (Transformation transformation : transformations) {
            pos = transformation.transform(pos);
        }
        return pos;
    }

    private BlockState transform(BlockState state) {
        for (Transformation transformation : transformations) {
            state = transformation.transform(state);
        }
        return state;
    }

    protected void set(BlockPos originalPos, BlockState state) {
        BlockPos pos = transform(originalPos);
        blocks.put(pos.asLong(), transform(state));
    }

    protected void rect(BlockPos pos, int width, int height, int depth, BlockState state) {
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                for (int z = 0; z < depth; z++) {
                    set(pos.add(x, y, z), state);
                }
            }
        }
    }

    protected void rotate(Transformation[] functions, Runnable action) {
        for (Transformation function : functions) {
            transformations.add(function);
            action.run();
            transformations.remove(transformations.size() - 1);
        }
    }

    protected void rotate(Runnable action) {
        rotate(new Transformation[]{NONE, CLOCKWISE_90, CLOCKWISE_180, COUNTERCLOCKWISE_90}, action);
    }

    public void place(World world, BlockPos pos) {
        for (Map.Entry<Long, BlockState> entry : blocks.entrySet()) {
            BlockState state = entry.getValue();
            BlockPos newPos = pos.add(BlockPos.fromLong(entry.getKey()));

            world.removeBlockEntity(newPos);
            world.setBlockState(newPos, state);

            handleBlockPlace(world, newPos, state);
        }
    }

    protected abstract void handleBlockPlace(World world, BlockPos pos, BlockState state);

    public static Transformation directionToTransformation(Direction direction) {
        switch (direction) {
            case NORTH: {
                return NONE;
            }
            case EAST: {
                return CLOCKWISE_90;
            }
            case SOUTH: {
                return CLOCKWISE_180;
            }
            case WEST: {
                return COUNTERCLOCKWISE_90;
            }
            default: {
                throw new MissingCaseException(direction);
            }
        }
    }

    public static Direction blockRotationToDirection(BlockRotation rotation) {
        switch (rotation) {
            case NONE: {
                return Direction.NORTH;
            }
            case CLOCKWISE_90: {
                return Direction.EAST;
            }
            case CLOCKWISE_180: {
                return Direction.SOUTH;
            }
            case COUNTERCLOCKWISE_90: {
                return Direction.WEST;
            }
            default: {
                throw new MissingCaseException(rotation);
            }
        }
    }

    protected void part(StructureContext context, BlockPos originalPos, StructurePart<?> part) {
        BlockPos pos = transform(originalPos);
        context.addPart(pos.getX(), pos.getY(), pos.getZ(), part);
    }

    protected List<Transformation> getTransformations() {
        return transformations;
    }

    private BlockPos pos = null;

    private BlockPos getPos() {
        return pos;
    }

    protected BlockPos getPosFromOrigin(BlockPos pos) {
        return transform(pos).add(getPos());
    }

    void setPos(BlockPos pos) {
        this.pos = pos;
    }
}