/*
	Lookup agent rev 0.0.2 for FIPAOS 1.3.3
	Written as a proof of concept by Ognen Duzlevski ( http://www.cs.usask.ca/undegrads/ogd116 )

	Mobile and Ubiquitous Computing Lab
	University of Saskatchewan, Saskatoon, Canada

	Purpose: The agent acts as a proxy for all other agents wishing to do a federated lookup. Since the current implementation of FipaOS (1.3.3) does not provide for inter-registering of directory facilitators on different platforms, we need to have an agent that will extract the foreign platforms from the acc.profile and register itself with all DFs on these platforms, thus being able to perform lookups when requested.

	The extraction, for now (it was easier) is done by simple string search for string "<ns1:HA>" in the acc.profile.

	Guidelines: Look at the fipaos\examples\dfsearch.txt file to see how to formulate a search. The reply will come back in the same form as the reply from a DF (test this with the iotestagent). There will be as many replies as there are DFs to be searched. You will know on which platform a particular agent is registered by parsing the contents of a reply and searching for a string starting with "df@" -> the rest will be the HAP. You can then extract the agents in the result string and utilize them by sending them direct messages.

	Limitations: the agent is tied to the platform it runs on -> it will only be able to register itself with and search the platforms listed in the acc.profile on a particular platform.

	Future: If we had an agent per platform waking up after the df/ams automatcally, we could have a federated search ability built-in. Although cross-registering DFs is the correct approach.

	Note: this is rev 0.0.1 - it was coded without designing ;) and is considered an ob-hack. I have tested the agent on a platform of three fipa-os'd machines and it worked fine. If the code seems messy and incorrect, it is only because it was done by a messy person.

	History:
	rev 0.0.2: separated the registration into a RegistrationTask. Things should work now (Tom) :)
*/

import fipaos.agent.*;
import fipaos.agent.task.*;
import fipaos.ont.fipa.*;
import fipaos.agent.conversation.*;
import fipaos.ont.fipa.fipaman.*;
//import fipaos.skill.db.*;
import fipaos.parser.acl.*;
import fipaos.agent.conversation.content.*;
import fipaos.util.StringParser;
import fipaos.parser.sl.*;
import fipaos.platform.df.SearchTask;
import fipaos.parser.ParserException;

import java.io.*;
import java.util.Vector;
import java.util.LinkedList;

public class LookupAgent extends FIPAOSAgent {

	private String platform_filename;
	private Vector HAP = new Vector(); // to keep possible HAPs
	private Vector DF = new Vector();  // to keep confirmed DFs

	public LookupAgent(String profile, String name, String owner) {
		super(profile, name, owner);
		// remember the filename for later
		// we will use it to get the acc.profile file
		platform_filename = profile;
		// now go on with the setup
		System.out.println("Initializing agent.");
		setListenerTask(new IdleTask());
		registerWithAMS();
		registerWithDF("lookup-agent");
		// get foreign HAPs
		//getPlatformAddresses();
		// register with all DFs
		//registerWithDFs();
	}

	public void registrationSucceeded(String agent) {
		System.out.println("Registration succeeded with " + agent + ".");
		if (!DF.contains(getLocalDFAID())) {
			DF.add(getLocalDFAID());
			System.out.println("Adding local df@" + getHAP());
		}
	}

	public void registrationFailed(String agent, String reason) {
		if (reason.compareTo(FIPAMANCONSTANTS.AGENT_ALREADY_REGISTERED) != 0)
			shutdown();
	}

	public void registrationRefused(String agent, String reason) {
		if (reason.compareTo(FIPAMANCONSTANTS.AGENT_ALREADY_REGISTERED) != 0)
			shutdown();
	}

	public void shutdown() {
		// empty for now
	}

	public class IdleTask extends Task {

		public IdleTask() {
			// do nothing
		}

		public void startTask() {
			// do nothing for now
			newTask(new RegistrationTask());
		}

		public void handleOther(Conversation conv) {
			System.out.println("handleOther() invoked -> sending a NOT_UNDERSTOOD back.");
			/* we are sending a "not-understood" if this method was invoked */
			ACL msg = conv.getACL(conv.getLatestMessageIndex());
			// print out the contents
			System.out.println("Performative: " + msg.getPerformative());
			AgentID sender = msg.getSenderAID();
			msg.setPerformative(FIPACONSTANTS.NOT_UNDERSTOOD);
			msg.setSenderAID(getAID());
			msg.setReceiverAID(sender);
			forward(msg);
		}

		public void handleAgree(Conversation conv) {
			// here we will add all valid DFs to our DF vector
			ACL msg = conv.getACL(conv.getLatestMessageIndex()); // get last message
			AgentID sender = msg.getSenderAID();			// get sender AID
			String senderName = sender.getName();			// get sender name
			if (senderName.startsWith("df@"))				// is it a DF?
				// if the df sender is not in the vector -> add it ;)
				if (!DF.contains(sender))
					System.out.println("An agree for a search came in from an unknown DF?");
		} // handleAgree()

		public void handleRequest(Conversation conv) {
			/*
				in this method we have to create an ACL message out of
				all agents that match the search criteria
				-> we are using the DF vector for a list of active DFs (this list is static!)

				due to a lack of forwarding features in fipaos rev 1.3.3
				we need to break down the communication two ways:
					* agent->lookup-agent->df
					* fd->lookup-agent->agent
			*/
			// first get this instance's name
			String this_agent = getAID().getName();
			// get last message
			ACL msg = conv.getACL(conv.getLatestMessageIndex());
			// get original content
			String cnt = StringParser.trimBrackets((String)msg.getContentObject());
			try {
				AgentManagementAction ama = new AgentManagementAction(cnt);
				// get the management request action
				String function = ama.getAction();
				if (function.equals("search")) {
					// send "Agree" first
					System.out.println("Incoming search message from: " + msg.getSenderAID().getName());
					ACL agree = new ACL();
					agree.setPerformative(FIPACONSTANTS.AGREE);
					agree.setSenderAID(getAID());
					agree.setReceiverAID(msg.getSenderAID());
					agree.setInReplyTo( msg.getReplyWith() );
					agree.setReplyWith( null );
					forward(agree);
					System.out.println("Sent agree msg to: " + msg.getSenderAID().getName());
					// now reroute the search requests to all known DFs
					for (int i=0; i<DF.size(); i++) {
						// get the DF AID
						AgentID df = (AgentID)DF.elementAt(i);
						// create new ACLMessage
						ACL fwd = new ACL();
						fwd.setPerformative(FIPACONSTANTS.REQUEST);
						fwd.setOntology(FIPAMANCONSTANTS.FIPA_AGENT_MANAGEMENT);
						fwd.setLanguage(FIPAMANCONSTANTS.FIPA_SL0);
						fwd.setProtocol(FIPACONSTANTS.FIPA_REQUEST);
						fwd.setReceiverAID(df);
						fwd.setSenderAID(getAID());
						// replace this agent's name with the df name
						StringBuffer newContent = new StringBuffer(cnt);
						int start = cnt.indexOf(this_agent);
						int end = start + this_agent.length();
						newContent.replace(start, end, df.getName());
						fwd.setContentObject("(" + newContent.toString() + ")");
						fwd.setReplyWith(msg.getReplyWith());
						// add original sender AID so that we know who to reroute the answer
						fwd.addReplyToAID(msg.getSenderAID());
						// send the new message
						forward(fwd);
						System.out.println("Forwarded search message to: " + df.getName());
					}
				} // if
			} catch (ParserException p) {
				System.out.println("Exception: " + p.getMessage());
			}
		}

		public void handleInform(Conversation conv) {
			// here replies from different agents are handled
			AgentID receiver = null;
			String this_agent = getAID().getName();
			// get the latest message arrived
			ACL msg = conv.getACL(conv.getLatestMessageIndex());
			AgentID sender = msg.getSenderAID();
			// get sender (DF) name
			String senderName = sender.getName();
			// get message contents
			String content = (String)msg.getContentObject();
			// check if it is from a DF
			if (!DF.contains(sender)) {
				System.out.println("A message from an unknown DF.");
				return;
			}
			// see if a message is aimed at someone else too
			// this is how we know it is a response to a rerouted search request
			// the original agent sender will be in ths field from handleRequest()
			LinkedList ll = (LinkedList)msg.getReplyToAIDs();
			if (ll.size() > 0)
				// yes, get the receiver
				receiver = (AgentID)ll.get(0);
			else
				// nothing to do with the inform so far
				return;
			// construct a new message
			System.out.println("Search reply came in from: " + senderName);
			ACL fwd = new ACL();
			//fwd.setProtocol(msg.getProtocol());
			fwd.setPerformative(FIPACONSTANTS.INFORM);
			//fwd.setLanguage(msg.getLanguage());
			//fwd.setOntology(msg.getOntology());
			fwd.setSenderAID(getAID());
			fwd.setReceiverAID(receiver);
			fwd.setInReplyTo(msg.getInReplyTo());
			// mangle the contents to change df name to this agent's name
			StringBuffer newContent = new StringBuffer(content);
			int start = content.indexOf(senderName);
			int end = senderName.length() + start;
			//replace the df name with this agent's name
			//newContent.replace(start, end, this_agent);
			// set the new contents
			fwd.setContentObject(newContent.toString());
			//System.out.println("Content: " + newContent.toString());
			// send the message
			forward(fwd);
			System.out.println("Rerouted message from " + senderName + " to " + receiver.getName());
		}

		public void handleRefuse(Conversation conv) {
			ACL msg = conv.getACL(conv.getLatestMessageIndex());
			AgentID sender = msg.getSenderAID();
			System.out.println("Refuse from " + sender.getName());
			if (sender.getName().indexOf("df") != -1)
				System.out.println("Registration with " + sender.getName() + " refused.");
		}

		public void shutdown() { System.exit(0); }
	} // IdleTask

	public class RegistrationTask extends Task {
	// added in rev 0.0.2
		public RegistrationTask() {
			// do nothing
		}

		public void startTask() {
			getDFAddresses();
			registerWithDFs();
		}

		private void getDFAddresses() {
			// obtain the platform addresses by parsing the acc.profile file by treating it line-by-line
			String startStr = "<ns1:HAP>";
			String endStr = "</ns1:HAP>";
			int startStrLen = startStr.length();
			StringBuffer sb = null;
			/* we are using the filename that was passed as the platform profile */
				try {
					File f = new File(platform_filename);
					// get the full path of the platform.profile file
					String absPath = f.getAbsolutePath();
					// get the last occurence of the path separator
					int lastIndex = absPath.lastIndexOf(f.separator);
					// now extract everything before that
					sb = new StringBuffer(absPath.substring(0, lastIndex+1));
					// get the new full pathname of acc.profile
					sb.append("acc.profile");
					// try to open the acc.profile file
					FileReader fr = new FileReader(new String(sb));
					LineNumberReader lr = new LineNumberReader(fr);
					String line = lr.readLine();
					while (line != null) {
						// look for HAP in line
						int startPos = line.indexOf(startStr);
						if (startPos > -1) {
							// string found, obtain ending marker
							int endPos = line.indexOf(endStr);
							if (endPos > -1) {
								// get the HAP (between start and end marker
								// and add it to the global vector
								String HAPn = line.substring(startPos+startStrLen, endPos);
								HAP.add(HAPn);
							}
						}
						line = lr.readLine();
					} // while
				} catch (NullPointerException np) {
					System.out.println("No acc.profile to parse. Shutting down...");
					shutdown();
				} catch (FileNotFoundException fe) {
					System.out.println("File " + sb + " not found. Shutting down...");
					shutdown();
				} catch (IOException ioe) {
					System.out.println("I/O error reading file " + sb + ". Shutting down...");
					shutdown();
				}
		}

		private void registerWithDFs() {
			// this method has to send registration requests with all DF@HAPs
			String content1 = "((action (agent-identifier :name ";
			String dfdesc = " :services (set (service-description :name lookup-agent :type lookup-agent ))";
			String content2 = " ) (register (df-agent-description ";
			String content3 = " :name (agent-identifier :name ";
			String content4 = " ) ) ) ) )";
			if (HAP.size() > 0) {
				// at least one HAP in the vector
				for (int i=0; i < HAP.size(); i++) {
					// build a registration message for each df
					ACLMessage msg = new ACLMessage();
					msg.setPerformative(FIPACONSTANTS.REQUEST);
					msg.setOntology(FIPAMANCONSTANTS.FIPA_AGENT_MANAGEMENT);
					msg.setLanguage(FIPAMANCONSTANTS.FIPA_SL0);
					msg.setProtocol(FIPACONSTANTS.FIPA_REQUEST);
					String agentName = getAID().getName();
					msg.setSender("(agent-identifier :name " + agentName + " )");
					String DFName = "df@" + (String)HAP.elementAt(i);
					msg.setReceiver("(agent-identifier :name " + DFName + " )");
					String content = content1+DFName+content2+dfdesc+content3+agentName+content4;
					msg.setContent(content);
					// send the message, reply as "inform"
					System.out.println("Trying to register with " + DFName);
					forward(msg);
				} // for
			} // if
		} // registerWithDFs()

		public void handleAgree(Conversation conv) {
			// this method is usually invoked upon registration from a DF
			// (but can be invoked by any agent agreeing to perform a service)
			// here we will add all valid DFs to our DF vector
			ACL msg = conv.getACL(conv.getLatestMessageIndex()); // get last message
			AgentID sender = msg.getSenderAID();			// get sender AID
			String senderName = sender.getName();			// get sender name
			if (senderName.startsWith("df@"))				// is it a DF?
				// if the df sender is not in the vector -> add it ;)
				if (!DF.contains(sender)) {
					System.out.println("Added " + senderName + " (registration succeeded).");
					DF.add(sender);
				}
		} // handleAgree()
	} // RegistrationTask

	public static void main(String args[]) {
		new LookupAgent(args[0], args[1], "FIPA-OS");
	}
}