package com.rs2hd.net.codec;

import org.apache.mina.common.ByteBuffer;
import org.apache.mina.common.IdleStatus;
import org.apache.mina.common.IoFuture;
import org.apache.mina.common.IoFutureListener;
import org.apache.mina.common.IoSession;
import org.apache.mina.filter.codec.CumulativeProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolCodecFilter;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;

import com.rs2hd.Constants;
import com.rs2hd.WorkerThread;
import com.rs2hd.model.PlayerDetails;
import com.rs2hd.net.Packet;
import com.rs2hd.packetbuilder.StaticPacketBuilder;
import com.rs2hd.util.Misc;
import com.rs2hd.util.log.Logger;

/**
 * Login protocol decoder.
 * @author Graham
 *
 */
public class RS2LoginProtocolDecoder extends CumulativeProtocolDecoder {

	/**
	 * Logger instance.
	 */
	private Logger logger = Logger.getInstance();

	private WorkerThread workerThread;

	public RS2LoginProtocolDecoder(WorkerThread workerThread) {
		this.workerThread = workerThread;
	}

	/**
	 * Parses the data in the provided byte buffer and writes it to
	 * <code>out</code> as a <code>Packet</code>.
	 *
	 * @param session The IoSession the data was read from
	 * @param in	  The buffer
	 * @param out	 The decoder output stream to which to write the <code>Packet</code>
	 * @return Whether enough data was available to create a packet
	 */
	@Override
	public boolean doDecode(IoSession session, ByteBuffer in, ProtocolDecoderOutput out) {
		try {
			Object loginStageObj = session.getAttribute("LOGIN_STAGE");
			int loginStage = 0;
			if(loginStageObj != null) {
				loginStage = (Integer)loginStageObj;
			}
			switch(loginStage) {
			case -3:
				if (in.remaining() >= 4) {
					final int loginOpcode = in.getInt();
					logger.info("Loginopcode " + loginOpcode);
					if (loginOpcode == 0) {
						session.write(RS2WorldListEncoder.encode(true, true));
					} else {
						session.write(RS2WorldListEncoder.encode(false, true));
					}
					return true;
				}
				in.rewind();
				break;
			case -2:
				if(8 <= in.remaining()) {
					for(int i = 0; i < 8; i++) {
						in.get();
					}
					StaticPacketBuilder ukeys = new StaticPacketBuilder();
					ukeys.setBare(true);
					for(int key : Constants.UPDATE_KEYS) {
						ukeys.addByte((byte) key);
					}
					session.write(ukeys.toPacket()).addListener(new IoFutureListener() {
						@Override
						public void operationComplete(IoFuture arg0) {
							arg0.getSession().close();
						}
					});
					return true;
				}
				in.rewind();
				return false;
			case -1:
				if(3 <= in.remaining()) {
				    int clientVersion = in.getInt();
				    if(clientVersion == 525) {
				    	StaticPacketBuilder u1Response = new StaticPacketBuilder();
	        			u1Response.setBare(true).addByte((byte) 0);
	        			session.write(u1Response.toPacket());
	        			session.setAttribute("LOGIN_STAGE", -2);
				    } else {
				    	StaticPacketBuilder u1Response = new StaticPacketBuilder();
	        			u1Response.setBare(true).addByte((byte) 6);
	        			session.write(u1Response.toPacket()).addListener(new IoFutureListener() {
							@Override
							public void operationComplete(IoFuture arg0) {
								arg0.getSession().close();
							}
	        			});
	        			session.removeAttribute("LOGIN_STAGE");
				    }
				    return true;
				}
				in.rewind();
				return false;
			case 0: //first login packets
				if(2 <= in.remaining()) {
					int protocolId = in.get() & 0xff;
					if(protocolId == 15) {
					    session.setAttribute("LOGIN_STAGE", -1);
					} else if (protocolId == 131) {
						session.setAttribute("LOGIN_STAGE", -3);
					} else {
						int nameHash = in.get() & 0xff;
					    long serverSessionKey = ((long) (java.lang.Math.random() * 99999999D) << 32) + (long) (java.lang.Math.random() * 99999999D);
					    StaticPacketBuilder s1Response = new StaticPacketBuilder();
					    s1Response.setBare(true).addByte((byte) 0).addLong(serverSessionKey);
					    session.setAttribute("SERVER_SESSION_KEY", serverSessionKey);
					    session.write(s1Response.toPacket());
					    session.setAttribute("LOGIN_STAGE", 1);
					    session.setAttribute("NAME_HASH", nameHash);
					    //Logger.log("protocolId="+protocolId+"; namePart="+namePart);
					    logger.info("Protocol id " + protocolId);
					}
					return true;
				} else {
					in.rewind();
					return false;
				}
			case 1: //here's where we get the username and password
				@SuppressWarnings("unused")
				int loginType = -1, loginPacketSize = -1;
				if(3 <= in.remaining()) {
					loginType = in.get() & 0xff; //should be 16 or 18
					loginPacketSize = in.getUnsignedShort();
					//Logger.log("loginType="+loginType);
				} else {
					in.rewind();
					return false;
				}
				if(loginPacketSize <= in.remaining()) {
					byte[] payload = new byte[loginPacketSize];
					in.get(payload);
					Packet p = new Packet(session, -1, payload);
					@SuppressWarnings("unused")
					int loginEncryptPacketSize = loginPacketSize - (36 + 1 + 1 + 2); // can't be negative
					int clientVersion = p.readInt();
					if(clientVersion != 525) {
						Logger.getInstance().error("Invalid ver : " + clientVersion);
						session.close();
						return true;
					}
					in.get();
					boolean memoryVersion = (p.readByte() & 0xff) == 1 ? true : false;
					boolean hd = p.readByte() == 1 ? true : false;
					boolean resized = p.readByte() == 1 ? true : false;
					short width = p.readShort();
					short height = p.readShort();
					Logger.getInstance().info("HD: " + hd + " Resized: " + resized + " Width: " + width + " Height: " + height
							+ " Memory version " + memoryVersion);
					in.get();
					for (int i = 0; i < 24; i ++) {
						in.get();
					}
					p.readRS2String();
					in.getInt();
					in.getInt();
					in.getShort();
					for (int i = 0; i < 28; i++ ) {
						in.getInt();
					}
					int blockOpcode = p.readByte() & 0xff; //hopefully same as (--loginEncryptPacketSize)
					if(blockOpcode != 10) {
						logger.info("Invalid login block opcode : " + blockOpcode);
						in.rewind();
						return false;
					}
					long clientSessionKey = p.readLong();
					long serverSessionKey = p.readLong();
					//int uid = p.readInt(); //unique identifier for this session i think ?
					long l = p.readLong();
					int hash = (int) (31 & l >> 16);
					if(hash != (Integer) session.getAttribute("NAME_HASH")) {
						// invalid name hash (possibly a bot attacking)
						session.close();
						return true;
					}
					String	user = Misc.longToPlayerName(l), //given username
							pass = p.readRS2String(); //given password

					int sessionKey[] = new int[4];
					sessionKey[0] = (int)(clientSessionKey >> 32);
					sessionKey[1] = (int)clientSessionKey;
					sessionKey[2] = (int)(serverSessionKey >> 32);
					sessionKey[3] = (int)serverSessionKey;

					// set in ISAAC
					for(int i = 0; i < 4; i++) sessionKey[i] += 50;
					// set out ISAAC

					session.removeAttribute("LOGIN_STAGE");
					session.removeAttribute("NAME_HASH");

					/**
					 * Here's where we add the user to the login queue, and if the login is
					 * accepted, we change their session filter to a standard RS2ProtocolCodec.
					 */
					logger.debug("Login request: [username="+user+",password="+pass+"].");

					PlayerDetails d = new PlayerDetails(user, pass, session, hd);
					workerThread.loadPlayer(d);

					session.setIdleTime(IdleStatus.BOTH_IDLE, Constants.SESSION_IDLE_TIME);

					session.getFilterChain().remove("protocolFilter");
					session.getFilterChain().addLast("protocolFilter", new ProtocolCodecFilter(new CodecFactory()));

					return true;
				} else {
					in.rewind();
					return false;
				}
			}
		} catch(Exception e) {
			//logger.stackTrace(e);
		}
		return false;
	}


	/**
	 * Releases the buffer used by the given session.
	 *
	 * @param session The session for which to release the buffer
	 * @throws Exception if failed to dispose all resources
	 */
	@Override
	public void dispose(IoSession session) throws Exception {
		super.dispose(session);
	}

}