package net.dodian.network.login;

import java.net.InetSocketAddress;
import java.security.SecureRandom;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;

import net.dodian.GameSettings;
import net.dodian.game.World;
import net.dodian.game.model.player.Player;
import net.dodian.network.PlayerSession;
import net.dodian.network.packet.PacketBuilder;
import net.dodian.network.packet.codec.PacketDecoder;
import net.dodian.network.packet.codec.PacketEncoder;
import net.dodian.network.security.IsaacRandom;
import net.dodian.network.sql.integration.ForumIntegration;
import net.dodian.util.Misc;
import net.dodian.util.StringUtils;

/**
 * A {@link FrameDecoder} which decodes
 * the login requests.
 *
 * @author Gabriel Hannason
 */
public final class LoginDecoder extends FrameDecoder {

  private static final int CONNECTED = 0;

  private static final int LOGGING_IN = 1;

  private int state = CONNECTED;

  private long seed;

  public static void sendReturnCode(Channel channel, int code) {
    channel.write(new PacketBuilder().put(code).toPacket())
      .addListener(arg0 -> arg0.getChannel().close());
  }

  @Override
  protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer)
    throws Exception {
    switch (state) {
      case CONNECTED:
        if (buffer.readableBytes() < 2) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }

        int request = buffer.readUnsignedByte();
        if (request != 14) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }
        buffer.readUnsignedByte();
        seed = new SecureRandom().nextLong();
        channel.write(new PacketBuilder().putLong(0).put((byte) 0).putLong(seed).toPacket());
        state = LOGGING_IN;
        return null;
      case LOGGING_IN:
        if (buffer.readableBytes() < 2) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }
        int loginType = buffer.readByte();
        if (loginType != 16 && loginType != 18) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }
        int blockLength = buffer.readByte() & 0xff;
        if (buffer.readableBytes() < blockLength) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }
        int magicId = buffer.readUnsignedByte();
        if (magicId != 0xFF) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }
        int clientVersion = buffer.readShort();

        if (clientVersion != GameSettings.GAME_VERSION) {
          sendReturnCode(channel, LoginResponses.OLD_CLIENT_VERSION);
          return null;
        }

        int memory = buffer.readByte();
        if (memory != 0 && memory != 1) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }


        int[] archiveCrcs = new int[9];
        for (int i = 0; i < 9; i++) {
          archiveCrcs[i] = buffer.readInt();
        }


        buffer.readUnsignedByte();


			/*ChannelBuffer rsaBuffer = buffer.readBytes(length);
      BigInteger bigInteger = new BigInteger(rsaBuffer.array());
			bigInteger = bigInteger.modPow(GameSettings.RSA_EXPONENT, GameSettings.RSA_MODULUS);
			rsaBuffer = ChannelBuffers.wrappedBuffer(bigInteger.toByteArray());*/



        int securityId = buffer.readByte();
        if (securityId != 10) {
          sendReturnCode(channel, LoginResponses.LOGIN_COULD_NOT_COMPLETE);
          return null;
        }

        long clientSeed = buffer.readLong();
        long seedReceived = buffer.readLong();
        if (seedReceived != seed) {
          sendReturnCode(channel, LoginResponses.LOGIN_BAD_SESSION_ID);
          return null;
        }

        int[] seed = new int[4];
        seed[0] = (int) (clientSeed >> 32);
        seed[1] = (int) clientSeed;
        seed[2] = (int) (this.seed >> 32);
        seed[3] = (int) this.seed;

        IsaacRandom decodingRandom = new IsaacRandom(seed);
        for (int i = 0; i < seed.length; i++) {
          seed[i] += 50;
        }


        int uid = buffer.readInt();
        String username = Misc.readString(buffer);
        String password = Misc.readString(buffer);
        String authCode = Misc.readString(buffer);
        String uuid = Misc.readString(buffer);

        if (username.length() > 12 || password.length() > 20) {
          sendReturnCode(channel, LoginResponses.LOGIN_INVALID_CREDENTIALS);
          return null;
        }

        username = Misc.formatText(username.toLowerCase());
        channel.getPipeline()
          .replace("encoder", "encoder", new PacketEncoder(new IsaacRandom(seed)));
        channel.getPipeline().replace("decoder", "decoder", new PacketDecoder(decodingRandom));

        return login(channel, new LoginDetailsMessage(username, password,
                                                       ((InetSocketAddress) channel
                                                                              .getRemoteAddress())
                                                         .getAddress().getHostAddress(), authCode, uuid,
                                                       clientVersion, uid));
    }
    return null;
  }

  public Player login(Channel channel, LoginDetailsMessage msg) {

    PlayerSession session = new PlayerSession(channel);

    Player player = new Player(session).setUsername(msg.getUsername())
                      .setLongUsername(StringUtils.stringToLong(msg.getUsername()))
                      .setPassword(msg.getPassword()).setHostAddress(msg.getHost())
                      .setSerialNumber(msg.getUuid());
    player.setAuthCode(msg.getAuthCode());

    session.setPlayer(player);

    int response = LoginResponses.getResponse(player, msg);


		if (msg.getUsername() != "Test") {
		//	response = ForumIntegration.checkUser(player);
		}

    if (response == LoginResponses.LOGIN_SUCCESSFUL) {
      if (World.addLoginRequest(player)) {
        return player;
      } else {
        response = LoginResponses.LOGIN_ACCOUNT_ONLINE;
      }
    }

    sendReturnCode(channel, response);
    return null;
  }

}