package cz.cuni.amis.pogamut.base.agent.impl;
   
   import java.net.InetAddress;
   import java.net.UnknownHostException;
   import java.rmi.server.UID;
   import java.util.Random;
   import java.util.UUID;
   
   import com.google.inject.Inject;
  import com.google.inject.name.Named;
  
  import cz.cuni.amis.pogamut.base.agent.IAgentId;
  import cz.cuni.amis.pogamut.base.utils.guice.AgentScoped;
  import cz.cuni.amis.utils.NullCheck;
  import cz.cuni.amis.utils.flag.Flag;
  import cz.cuni.amis.utils.token.Token;
  import cz.cuni.amis.utils.token.Tokens;
  
  /**
   * Default AgentId providing unique id based on {@link UID} and IP of the host.
   * @author Jimmy
   */
  @AgentScoped
  public class AgentId implements IAgentId {
  
  	public static final String AGENT_NAME_DEPENDENCY = "AgentName";
  	
  	/**
  	 * Provides unique number of the agent instance in the scope of JVM.
  	 */
  	private static int agentCounter = 0;
  	
  	protected static Random random = new Random(System.currentTimeMillis());
  	
  	public static final String NO_NAME = "no_name";
  
  	private Flag<String> name = new Flag<String>(NO_NAME);
  
  	private Token token;
  	
  	public AgentId() {
  		UUID uuid = null;
  		try {
  			synchronized(random) {
  				uuid = new UUID(random.nextLong(), random.nextLong());
  			}
  			this.token = Tokens.get(getClass().getSimpleName() + "-" + (++agentCounter) + "@"
  					+ InetAddress.getLocalHost().getCanonicalHostName() + "/" + uuid.toString());
  		} catch (UnknownHostException ex) {
  			if (uuid == null) throw new IllegalStateException("Can't initialize AgentId, instantiation of UUID failed.");
  			this.token = Tokens.get(getClass().getSimpleName() + "-" + (++agentCounter) + "@unknownHost/" + uuid.toString());
  		}
  	}
  	
  	@Inject
  	public AgentId(@Named(AGENT_NAME_DEPENDENCY) String agentName) {
  		NullCheck.check(agentName, "name");
  		UUID uuid = null;
  		try {
  			synchronized(random) {
  				uuid = new UUID(random.nextLong(), random.nextLong());
  			}
  			this.token = Tokens.get(agentName + "-" + (++agentCounter) + "@"
  					+ InetAddress.getLocalHost().getCanonicalHostName() + "/" + uuid.toString());
  		} catch (UnknownHostException ex) {
  			this.token = Tokens.get(getClass().getSimpleName() + "-" + (++agentCounter) + "@unknownHost/" + uuid.toString());
  		}
  		getName().setFlag(agentName);
  	}
  	
  	@Override
  	public int hashCode() {
  		return this.token.hashCode();
  	}
  	
  	@Override
  	public boolean equals(Object obj) {
  		if (obj == null) return false;
  		if (!(obj instanceof AgentId)) return false;
  		return token.equals(((AgentId)obj).token);
  	}
  	
  	@Override
  	public Flag<String> getName() {
  		return name;
  	}
  
  	@Override
  	public long[] getIds() {
  		return token.getIds();
  	}
  
  	@Override
  	public String getToken() {
  		return token.getToken();
  	}
  	
  	@Override
  	public String toString() {
 		return "AgentId[" + getToken() + "]";
 	}
 	
 }