/**
 * <p>
 * Copyright © 2009-2010, Bruce-Robert Pocock
 * </p>
 * <p>
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 * </p>
 * <p>
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 * </p>
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 * </p>
 * 
 * @author brpocock
 */

package org.starhope.appius.via;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;
import java.util.Vector;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentSkipListSet;

import org.starhope.appius.except.NotFoundException;
import org.starhope.appius.game.AppiusClaudiusCaecus;
import org.starhope.appius.util.CastsToJSON;

/**
 * @author brpocock
 * 
 */
public class Via {

	/**
	 * WRITEME: document this field (brpocock, Jan 15, 2010) munita
	 * (Via)
	 */
	private static final ConcurrentHashMap <Class <? extends ViaMunita <?>>, ConcurrentSkipListSet <Entry <String, Vector <Class <?>>>>> classMethodIntrospectionCache =
		new ConcurrentHashMap <Class <? extends ViaMunita <?>>, ConcurrentSkipListSet <Entry <String, Vector <Class <?>>>>> ();


	/**
	 * TODO: document this field (brpocock, Nov 19, 2009) peers (Via)
	 */
	private static ConcurrentSkipListSet <ViaHost> peers =
		new ConcurrentSkipListSet <ViaHost> ();

	/**
	 * WRITEME: document this field (brpocock, Jan 18, 2010) RPC_CALL
	 * (Via)
	 */
	private static final String RPC_CALL = "\ufeed\ud00d";

	/**
	 * WRITEME: document this field (brpocock, Jan 18, 2010) RPC_HELLO
	 * (Via)
	 */
	private static final String RPC_HELLO = "\ufeed\ud0c5";

	private final static ConcurrentHashMap <String,Socket> socketCache = new ConcurrentHashMap <String, Socket> ();

	/**
	 * TODO: document this method (brpocock, Jan 15, 2010)
	 * 
	 * @param o an object of the class to be made ready
	 */
	@SuppressWarnings ("unchecked")
	private static void classReady (final ViaMunita <?> o) {
		final Class <? extends ViaMunita <?>> klass =
			(Class <? extends ViaMunita <?>>) o.getClass ();
		if (Via.classMethodIntrospectionCache.containsKey (klass))
			return;
		/**
		 * Build up the introspection cache for the given class
		 */
		final ConcurrentSkipListSet <Entry <String, Vector <Class <?>>>> classMethods =
			new ConcurrentSkipListSet <Entry <String, Vector <Class <?>>>> ();
		for (final Method method : klass.getMethods ()) {
			final Vector <Class <?>> signature =
				new Vector <Class <?>> ();
			for (final Class <?> parameter : method
					.getParameterTypes ()) {
				signature.add (parameter);
			}
			final HashMap <String, Vector <Class <?>>> fakeMap =
				new HashMap <String, Vector <Class <?>>> ();
			fakeMap.put (method.getName (), signature);
		}
		Via.classMethodIntrospectionCache.put (klass, classMethods);
	}

	/**
	 * TODO: document this method (brpocock, Jan 15, 2010)
	 * 
	 * @param remote WRITEME
	 * @param methodName WRITEME
	 * @param args WRITEME
	 * @return WRITEME
	 */
	private static Object[] conformRPCArgs (final ViaMunita <?> remote,
			final String methodName, final Object... args) {
		return args; // FIXME
	}

	/**
	 * TODO: document this method (brpocock, Jan 13, 2010)
	 * 
	 * @param o the local half of the connection to be connected to its
	 *            remote peer
	 * @throws DoNotCrossTheRubicon WRITEME
	 */
	public static void connect (final ViaMunita <?> o)
	throws DoNotCrossTheRubicon {
		// TODO Auto-generated method stub (brpocock, Jan 13, 2010)

	}

	private static Object deserialize (final String in) throws ViaCommunicationsException {
		final char indicator = in.charAt (0);
		switch (indicator) {
		case '“':
		default:
			throw new ViaCommunicationsException ("fmt.indicator", "Data Format error, expected type indicator character, got “" + indicator + "”");
		}
	}

	/**
	 * @param localHalf Local half of the connection
	 */
	public static void flush (final ViaMunita <?> localHalf) {
		for (final Method m : localHalf.getClass ().getMethods ()) {
			final SetRemote a;
			a = m.getAnnotation (SetRemote.class);
			if (null != a) {
				Via.setRemote (localHalf, m, a);
			}
		}
	}

	/**
	 * TODO: document this method (brpocock, Jan 11, 2010)
	 * 
	 * @param url WRITEME
	 * @return WRITEME
	 */
	public static String getPathFromURL (final String url) {
		// TODO Auto-generated method stub (brpocock, Jan 11, 2010)
		return null;
	}


	/**
	 * TODO: document this method (brpocock, Jan 11, 2010)
	 * 
	 * @param url WRITEME
	 * @return WRITEME
	 */
	public static int getPortNumberFromURL (final String url) {
		// TODO Auto-generated method stub (brpocock, Jan 11, 2010)
		return 0;
	}

	/**
	 * TODO: document this method (brpocock, Jan 11, 2010)
	 * 
	 * @param url WRITEME
	 * @return WRITEME
	 */
	public static String getServerNameFromURL (final String url) {
		// TODO Auto-generated method stub (brpocock, Jan 11, 2010)
		return null;
	}

	/**
	 * TODO: document this method (brpocock, Nov 19, 2009)
	 * 
	 * @throws NumberFormatException WRITEME
	 * @throws UnknownHostException WRITEME
	 * @throws IOException WRITEME
	 * @throws NotFoundException WRITEME
	 */
	public static void joinPeers ()
	throws NumberFormatException, UnknownHostException,
	IOException, NotFoundException {
		if (Via.peers.size () > 0) return;
		// final Socket render = new Socket (AppiusConfig
		// .getConfig ("org.starhope.appius.via.rendezvous"),
		// AppiusConfig.getInt ("org.starhope.appius.via.port"));
		// final InputStream in = render.getInputStream ();
		// final OutputStream out = render.getOutputStream ();
		// TODO
	}

	/**
	 * @param remote WRITEME
	 * @param methodName WRITEME
	 * @param args WRITEME
	 * @return WRITEME
	 */
	public static Object rpc (final ViaMunita <?> remote,
			final String methodName, final Object ... args) {
		Via.classReady (remote);
		final Object conformedArgs [] = Via.conformRPCArgs(remote, methodName, args);
		final StringBuilder rpcCall = new StringBuilder ();
		rpcCall.append (Via.RPC_CALL);
		for (final Object o : conformedArgs) {
			rpcCall.append (Via.serialize (o));
		}
		final Socket socket =
			Via.socketCache.get (remote.getViaAppiaHostname ()
					+ ":" + remote.getViaAppiaServerPort ());
		OutputStream out = null;
		try {
			out = socket.getOutputStream ();
		} catch (final IOException e) {
			throw AppiusClaudiusCaecus
			.fatalBug (
					"Caught a IOException in rpc obtaining output stream",
					e);
		}
		try {
			out.write (rpcCall.toString ().getBytes ());
		} catch (final IOException e) {
			throw AppiusClaudiusCaecus.fatalBug (
					"Caught a IOException in rpc write", e);
		}
		BufferedInputStream in = null;
		try {
			in = new BufferedInputStream (socket.getInputStream ());
		} catch (final IOException e) {
			throw AppiusClaudiusCaecus
			.fatalBug (
					"Caught a IOException in rpc obtaining input stream",
					e);
		}

		return null; // FIXME
	}

	/**
	 * TODO: document this method (brpocock, Jan 18, 2010)
	 * 
	 * @param o WRITEME
	 * @return WRITEME
	 */
	private static String serialize (final Object o) {
		final Class<?> klass = o.getClass ();
		if (o instanceof CastsToJSON) {
			final String json$ =
				((CastsToJSON) o).toJSON ().toString ();
			final StringBuilder serial = new StringBuilder ();
			serial.append ("J");
			serial.append (klass.getCanonicalName ());
			serial.append ("@");
			serial.append (json$.length ());
			serial.append (json$);
			return serial.toString ();
		}
		if (klass.equals (String.class)) {
			final StringBuilder serial = new StringBuilder ();
			serial.append ("“");
			serial.append ( ((String) o).length ());
			serial.append (o);
			return serial.toString ();
		}
		if (klass.equals (int.class)) {
			final StringBuilder serial = new StringBuilder ();
			serial.append ("i(");
			serial.append (String.valueOf (o));
			serial.append (")");
			return serial.toString ();
		}
		if (klass.equals (char.class)) return "c" + o;
		if (klass.equals (float.class))
			return "f(" + String.valueOf (o) + ")";
		if (klass.equals (double.class))
			return "d(" + String.valueOf (o) + ")";
		if (klass.equals (Integer.class))
			return "I(" + o.toString () + ")";
		if (klass.equals (Character.class)) return "C" + o.toString ();
		if (klass.equals (Float.class))
			return "F(" + o.toString () + ")";
		if (klass.equals (Double.class))
			return "D(" + o.toString () + ")";
		if (klass.equals (byte.class))
			return "b(" + String.valueOf (o) + ")";
		if (klass.equals (Byte.class))
			return "B(" + o.toString () + ")";

		final String stringified = o.toString ();
		return "¿" + klass.getCanonicalName () + "?" + stringified.length () + stringified;
	}

	/**
	 * @param remote WRITEME
	 * @param m WRITEME
	 * @param a WRITEME
	 */
	private static void setRemote (final ViaMunita <?> remote,
			final Method m, final SetRemote a) {
		// TODO Auto-generated method stub

	}

	/**
	 * TODO: document this method (brpocock, Nov 19, 2009)
	 * 
	 * @return WRITEME
	 */
	public Set <ViaHost> getPeers () {
		final HashSet <ViaHost> myPeers = new HashSet <ViaHost> ();
		myPeers.addAll (Via.peers);
		return myPeers;
	}

}