package org.server.net.codec;

import java.util.Random;

import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.serialization.ObjectDecoder;
import org.server.Engine;
import org.server.net.Session;

/**
 * Decodes the rs2 login protocol.
 * @author PrimaDude.
 */
public class LoginDecoder extends ObjectDecoder {

    private ChannelHandlerContext context;

    public ChannelHandlerContext getContext() {
        return context;
    }

    public LoginDecoder(ChannelHandlerContext context) {
        this.context = context;
    }

    public void setContext(ChannelHandlerContext context) {
        this.context = context;
    }

    public static String readRS2String(ChannelBuffer buffer) {
        StringBuffer stringBuffer = new StringBuffer();
        byte b;
        while((b = buffer.readByte()) != 10) {
            stringBuffer.append((char) b);
        }
        return stringBuffer.toString();
    }

    @Override
    protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception {
        Session session = (Session) getContext().getAttachment();
        Object loginStageObj = session.getAttribute("LOGIN_STAGE");
        int loginStage = 0;
        if (loginStageObj != null) {
            loginStage = (Integer) loginStageObj;
        }
        Engine.print("Session loginStage: [" + loginStage + "]");
        switch (loginStage) {
            case 0:
                if (buffer.readableBytes() >= 2) {
                    int loginId = buffer.readByte() & 0xFF;
                    if (loginId != 14) {
                        Engine.print("Invalid login id: " + loginId);
                        return false;
                    }
                    @SuppressWarnings("unused")
                    int namePart = buffer.readByte() & 0xFF;

                    long sessionKey = new Random().nextLong();
                    ChannelBuffer out = ChannelBuffers.dynamicBuffer();
                    for (int i = 0; i < 9; i++) {
                        out.writeByte(0);
                    }
                    out.writeLong(sessionKey);
                    channel.write(out);
                    session.putAttribute("LOGIN_STAGE", 1);
                }
                return false;
            case 1:
                int loginType = -1,
                loginPacketSize = -1;
                if (buffer.readableBytes() >= 2) {
                    loginType = buffer.readByte() & 0xff;
                    loginPacketSize = buffer.readByte() & 0xff;
                    if (loginType != 16 && loginType != 18) {
                        Engine.print("Invalid login type: " + loginType);
                        return false;
                    }
                } else {
                    buffer.resetReaderIndex();
                    return false;
                }
                if (buffer.readableBytes() >= loginPacketSize) {
                    if (buffer.readUnsignedByte() != 255) {
                        return false;
                    }
                    short revision = buffer.readShort();
                    if (revision != 317) {
                        Engine.print("Invalid client revision: " + revision);
                        return false;
                    }
                    @SuppressWarnings("unused")
                    int memoryVersionType = buffer.readByte();
                    for (int i = 0; i < 9; i ++) {
                        buffer.readInt();
                    }
                    @SuppressWarnings("unused")
                    int encryptedPacketSize = buffer.readByte();
                    @SuppressWarnings("unused")
                    int encryptedPacketId = buffer.readByte();

                    long clientSessionKey = buffer.readLong();
                    long serverSessionKey = buffer.readLong();
                    if (clientSessionKey != serverSessionKey) {
                        Engine.print("Invalid server or client session key: Server["
                                + serverSessionKey +"], Client["+ clientSessionKey +"]");
                        return false;
                    }
                    @SuppressWarnings("unused")
                    int uid = buffer.readInt();
                    String username = readRS2String(buffer);
                    String password = readRS2String(buffer);
                    Engine.print("Player login: Username["+ username +"], Password["+ password +"].");
                } else {
                    buffer.resetReaderIndex();
                    return false;
                }
        }
        return this;
    }

}