DeltaZern/paper-server/src/main/java/com/destroystokyo/paper/entity/PaperPathfinder.java

package com.destroystokyo.paper.entity;

import org.apache.commons.lang.Validate;
import org.bukkit.Location;
import org.bukkit.craftbukkit.entity.CraftLivingEntity;
import org.bukkit.entity.LivingEntity;
import org.bukkit.entity.Mob;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import net.minecraft.world.level.pathfinder.Node;
import net.minecraft.world.level.pathfinder.Path;
import java.util.ArrayList;
import java.util.List;

public class PaperPathfinder implements com.destroystokyo.paper.entity.Pathfinder {

    private net.minecraft.world.entity.Mob entity;

    public PaperPathfinder(net.minecraft.world.entity.Mob entity) {
        this.entity = entity;
    }

    @Override
    public Mob getEntity() {
        return (Mob) entity.getBukkitEntity();
    }

    public void setHandle(net.minecraft.world.entity.Mob entity) {
        this.entity = entity;
    }

    @Override
    public void stopPathfinding() {
        entity.getNavigation().stop();
    }

    @Override
    public boolean hasPath() {
        return entity.getNavigation().getPath() != null && !entity.getNavigation().getPath().isDone();
    }

    @Nullable
    @Override
    public PathResult getCurrentPath() {
        Path path = entity.getNavigation().getPath();
        return path != null && !path.isDone() ? new PaperPathResult(path) : null;
    }

    @Nullable
    @Override
    public PathResult findPath(Location loc) {
        Validate.notNull(loc, "Location can not be null");
        Path path = entity.getNavigation().createPath(loc.getX(), loc.getY(), loc.getZ(), 0);
        return path != null ? new PaperPathResult(path) : null;
    }

    @Nullable
    @Override
    public PathResult findPath(LivingEntity target) {
        Validate.notNull(target, "Target can not be null");
        Path path = entity.getNavigation().createPath(((CraftLivingEntity) target).getHandle(), 0);
        return path != null ? new PaperPathResult(path) : null;
    }

    @Override
    public boolean moveTo(@Nonnull PathResult path, double speed) {
        Validate.notNull(path, "PathResult can not be null");
        Path pathEntity = ((PaperPathResult) path).path;
        return entity.getNavigation().moveTo(pathEntity, speed);
    }

    @Override
    public boolean canOpenDoors() {
        return entity.getNavigation().pathFinder.nodeEvaluator.canOpenDoors();
    }

    @Override
    public void setCanOpenDoors(boolean canOpenDoors) {
        entity.getNavigation().pathFinder.nodeEvaluator.setCanOpenDoors(canOpenDoors);
    }

    @Override
    public boolean canPassDoors() {
        return entity.getNavigation().pathFinder.nodeEvaluator.canPassDoors();
    }

    @Override
    public void setCanPassDoors(boolean canPassDoors) {
        entity.getNavigation().pathFinder.nodeEvaluator.setCanPassDoors(canPassDoors);
    }

    @Override
    public boolean canFloat() {
        return entity.getNavigation().pathFinder.nodeEvaluator.canFloat();
    }

    @Override
    public void setCanFloat(boolean canFloat) {
        entity.getNavigation().pathFinder.nodeEvaluator.setCanFloat(canFloat);
    }

    public class PaperPathResult implements com.destroystokyo.paper.entity.PaperPathfinder.PathResult {

        private final Path path;
        PaperPathResult(Path path) {
            this.path = path;
        }

        @Nullable
        @Override
        public Location getFinalPoint() {
            Node point = path.getEndNode();
            return point != null ? toLoc(point) : null;
        }

        @Override
        public boolean canReachFinalPoint() {
            return path.canReach();
        }

        @Override
        public List<Location> getPoints() {
            List<Location> points = new ArrayList<>();
            for (Node point : path.nodes) {
                points.add(toLoc(point));
            }
            return points;
        }

        @Override
        public int getNextPointIndex() {
            return path.getNextNodeIndex();
        }

        @Nullable
        @Override
        public Location getNextPoint() {
            if (path.isDone()) {
                return null;
            }
            return toLoc(path.nodes.get(path.getNextNodeIndex()));
        }
    }

    private Location toLoc(Node point) {
        return new Location(entity.level().getWorld(), point.x, point.y, point.z);
    }
}