Path-find to a nearby block lit by sunlight

PathFinderExample.jar

package com.comphenix.example;

import net.minecraft.server.EntityPlayer;
import net.minecraft.server.PathEntity;
import net.minecraft.server.PathPoint;
import net.minecraft.server.WorldServer;

import org.bukkit.ChatColor;
import org.bukkit.DyeColor;
import org.bukkit.Location;
import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.block.Block;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.craftbukkit.CraftWorld;
import org.bukkit.craftbukkit.entity.CraftPlayer;

import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.java.JavaPlugin;

public class PathFinderExample extends JavaPlugin implements Listener {
    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (args.length > 0) {
            sender.sendMessage("This command doesn't take any arguments.");
            return true;
        }

        if (label.equalsIgnoreCase("performaction")) {
            if (sender instanceof Player)
                performAction((Player) sender, args);
            else
                performAction(sender);
            return true;
        }

        return false;
    }

    private void performAction(CommandSender sender) {
        sender.sendMessage("Cannot perform action on console.");
    }

    private void performAction(Player sender, String[] args) {
        PathEntity path = getSurfacePath(sender, 10);
        
        // Print the result
        if (path != null) {
            displayPathLocally(sender, path, Material.WOOL, DyeColor.GREEN.getData());
        } else {
            sender.sendMessage(ChatColor.RED + "Unable to find path.");
        }
    }
    
    private PathEntity getSurfacePath(Player player, int maximumDistance) {
        World world = player.getWorld();
        
        Location center = player.getLocation();
        int centerX = center.getBlockX();
        int centerZ = center.getBlockZ();
        
        int maximumSquared = maximumDistance * maximumDistance;
        
        // Find suitable locations in a 20x20 rectangle
        for (int dX = -maximumDistance; dX < maximumDistance; dX++) {
            for (int dZ = -maximumDistance; dZ < maximumDistance; dZ++) {
                
                Block highest = world.getHighestBlockAt(centerX + dX, centerZ + dZ);
                
                // The shortest (direct) distance must be valid first and foremost
                if (highest.getLocation().distanceSquared(center) < maximumSquared) {
                    
                    PathEntity path = getPath(player, highest.getLocation(), maximumDistance);
                    
                    if (path != null) {
                        return path;
                    }
                }
            }
        }
        
        return null;
    }
    
    private PathEntity getPath(Entity source, Location destination, int maximumDistance) {
        WorldServer nmsWorld = ((CraftWorld) source.getWorld()).getHandle();
        EntityPlayer entity = ((CraftPlayer) source).getHandle();
    
        return nmsWorld.a(entity, destination.getBlockX(), destination.getBlockY(), destination.getBlockZ(), 
                maximumDistance, true, false, false, true);
    }
    
    private void displayPathLocally(Player sender, PathEntity path, Material material, int data) {
        for (int i = 0; i < path.d(); i++) {
            PathPoint point = path.a(i);
            Location loc = new Location(sender.getWorld(), point.a, point.b, point.c);
            
            // "Display" the path
            sender.sendBlockChange(loc, material, (byte) (data & 0xFF));
        }
    }
}