content: package tanks.registry;
  
  import tanks.Game;
  import tanks.tank.Tank;
  import tanks.tank.TankUnknown;
  
  import java.lang.reflect.Constructor;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Random;
  
  public class RegistryTank 
  {
  	public HashMap<String, HashSet<String>> tankMusics = new HashMap<>();
  
  	public ArrayList<TankEntry> tankEntries = new ArrayList<>();
  	protected double maxTankWeight = 0;
  
  	public static class TankEntry
  	{
  		public final Class<? extends Tank> tank;
  		public final String name;
  		public final double weight;
  
  		protected double startWeight;
  		protected double endWeight;
  
  		public boolean isBoss;
  
  		protected RegistryTank registryTank;
  
  		public TankEntry(RegistryTank r, Class<? extends Tank> tank, String name, double weight)
  		{
  			this.tank = tank;
  			this.name = name;
  			this.weight = weight;
  			this.registryTank = r;
  
  			r.tankEntries.add(this);
  		}
  
  		public TankEntry(RegistryTank r, Class<? extends Tank> tank, String name, double weight, boolean isBoss)
  		{
  			this(r, tank, name, weight);
  			this.isBoss = isBoss;
  		}
  
  		public void initialize()
  		{
  			this.startWeight = registryTank.maxTankWeight;
  			registryTank.maxTankWeight += weight;
  			this.endWeight = registryTank.maxTankWeight;
  		}
  
  		protected TankEntry()
  		{
  			this.tank = TankUnknown.class;
  			this.name = "unknown";
  			this.weight = 0;
  		}
  
  		protected TankEntry(String name)
  		{
  			this.tank = TankUnknown.class;
  			this.name = name;
  			this.weight = 0;
  		}
  
  		public Tank getTank(double x, double y, double a)
  		{
  			try 
  			{
  				Constructor<? extends Tank> c = tank.getConstructor(String.class, double.class, double.class, double.class);
  				Tank t = c.newInstance(this.name, x, y, a);
  				t.fromRegistry = true;
  				t.musicTracks = Game.registryTank.tankMusics.get(this.name);
  
  				if (t.musicTracks == null)
  					t.musicTracks = new HashSet<>();
  
  				return t;
  			}
  			catch (Exception e)
  			{
  				Game.exitToCrash(e);
  				return null;
  			}
  		}
  
  		public static TankEntry getUnknownEntry()
  		{
  			return new TankEntry();
  		}
  
  		public static TankEntry getUnknownEntry(String name)
  		{
  			return new TankEntry(name);
  		}
  	}
  
  	public TankEntry getRandomTank()
  	{
  		return getRandomTank(null);
  	}
  
  	public TankEntry getRandomTank(Random rand)
  	{
  		double d = Math.random();
  
  		if (rand != null)
  			d = rand.nextDouble();
  
  		if (this.tankEntries.size() <= 0)
  			throw new RuntimeException("the tank registry file is empty. please register some tanks!");
  
  		double random = d * maxTankWeight;
  		for (int i = 0; i < tankEntries.size(); i++)
  		{
  			TankEntry r = tankEntries.get(i);
  
  			if (random >= r.startWeight && random < r.endWeight)
  			{
  				return r;
  			}
  		}
  
  		return TankEntry.getUnknownEntry();
  	}
  
  	public TankEntry getEntry(String name)
  	{		
  		for (int i = 0; i < tankEntries.size(); i++)
  		{
  			TankEntry r = tankEntries.get(i);
  
  			if (r.name.equals(name))
  			{
  				return r;
  			}
  		}
  
  		return TankEntry.getUnknownEntry(name);
  	}
  
  	public TankEntry getEntry(int number)
  	{		
  		return tankEntries.get(number);
  	}
  }
  