package de.se.buzzer.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.SocketTimeoutException;
import java.net.UnknownHostException;
import java.util.Arrays;

import android.util.Log;

/**
 * 
 * @author M. Friedeboldt
 */
public class MConnection implements Constants {

    /** Port to Buzzer Server */
    private static final int    PORT = ###########;

    /** Host to Buzzer Server */
    private static final String HOST = "192.168.178.20";

    /** Socket to Buzzer Server */
    private Socket              outputLine;

    /**
     * Construktor
     */
    public MConnection() throws UnknownHostException, IOException {
        // Connect
        connect();
    }

    /**
     * @throws IOException 
     * @throws UnknownHostException 
     */
    public void connect() throws UnknownHostException, IOException {
        Log.d( "MConnection", "Create Connect to (" + HOST + ":" + PORT + ")" );
        outputLine = new Socket( HOST, PORT );
        Log.d( "MConnection", "OK Create Connect to (" + PORT + ")" );
    }

    /**
     * Create Session and register on Buzzer Server<br>
     * - CMD_HELLO  >> SEND<br>
     * - Session ID << READ<br>
     * @return
     * @throws Exception
     */
    public long createSession() throws Exception {

        // Anfrage
        Log.d( "MConnection", "Send cmd Hello" );
        sendByte( CMD_HELLO );
        Log.d( "MConnection", "OK Send cmd Hello" );

        // Empfang Session ID
        Log.d( "MConnection", "Read Session ID" );
        long t = readSession();
        Log.d( "MConnection", "OK Read Session ID[" + t + "]" );
        return t;
    }

    /**
     * Send Question to Server.<br>
     * - CMD_QESTION    >> SEND<br>
     * - Session ID     >> SEND<br>
     * - Lenght Message >> SEND<br>
     * - Message        >> SEND<br>
     * @param sid
     * @param question
     * @throws Exception
     */
    public void sendQuestion(long sid, String question) throws Exception {
        // Anfrage Byte
        Log.d( "MConnection", "Send cmd Question" );
        sendByte( CMD_QESTION );
        Log.d( "MConnection", "OK Send cmd Question" );

        // Session
        sendSession( sid );

        // Lenght
        sendInt( question.length() );

        // Question
        sendData( question );
    }

    /**
     * Is Question Ready on Buzzer Server.<br>
     * - CMD_ANSWER_READY  >> SEND<br>
     * - byte              << READ<br>
     * @param sid
     * @return
     */
    public boolean isQuestionReady(long sid) throws Exception {
        // Send CMD Byte
        Log.d( "MConnection", "Send cmd CMD_ANSWER_READY" );
        sendByte( CMD_ANSWER_READY );
        Log.d( "MConnection", "Send cmd CMD_ANSWER_READY OK" );

        // Session
        sendSession( sid );

        // Ergebnis
        byte b = getByte();
        Log.d( "MConnection", "Read CMD_ANSWER_READY [" + b + "]" );
        return b == 1;
    }

    /**
     * Get the count from question<br>
     * - CMD_CONTENT     >> SEND<br>
     * - Session ID      >> SEND<br>
     * - count           << READ<br>
     * @param sid
     * @return
     * @throws Exception
     */
    public int readAnswerCount(long sid) throws Exception {
        // Send CMD Byte
        Log.d( "MConnection", "Send cmd CMD_ANSWER_COUNT" );
        sendByte( CMD_ANSWER_COUNT );
        Log.d( "MConnection", "Send cmd CMD_ANSWER_COUNT OK" );

        // Send Session
        sendSession( sid );
        
        // Count
        return getInt();
    }

    /**
     * Read Content from Server.<br>
     * - CMD_CONTENT     >> SEND<br>
     * - Session ID      >> SEND<br>
     * - index           >> SEND<br>
     * - msg lenght      << READ<br>
     * - msg             << READ<br>
     * @param sid
     * @param index
     * @return
     * @throws Exception
     */
    public String readContent(long sid, int index, int max) throws Exception {
        // Send CMD Byte
        Log.d( "MConnection", "Send cmd CMD_CONTENT" );
        sendByte( CMD_CONTENT );
        Log.d( "MConnection", "Send cmd CMD_CONTENT OK" );

        // Send Session
        sendSession( sid );

        // Send Index + Max
        sendInt( index );
        sendInt( max );

        // Read anz + Content
        int anz = getInt();
        return readData( anz );
    }

    /**
     * Close the Session.<br>
     * - CMD_CLOSE       >> SEND<br>
     * - Session ID      >> SEND<br>
     * @param sid
     */
    public void closeSession(long sid) {
        // Send CMD Byte
        Log.d( "MConnection", "Send cmd CMD_CLOSE" );
        sendByte( CMD_CLOSE );
        Log.d( "MConnection", "Send cmd CMD_CLOSE OK" );

        // Send Session
        sendSession( sid );
    }

    //*******************************************
    //*******************************************
    //  IO - HELPER 
    //*******************************************
    //*******************************************

    /**
     * sending Session ID
     * @param i
     */
    private void sendSession(long l) {
        if ( outputLine != null && outputLine.isConnected() ) {
            try {
                byte[] ba = new byte[8];
                for ( int i = 0; i < 64; i += 8 ) {
                    ba[i >> 3] = new Long( (l & (255L << i)) >> i ).byteValue();
                }
                outputLine.getOutputStream().write( ba );
            } catch ( IOException e ) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @return
     * @throws Exception
     */
    private long readSession() throws Exception {
        try {
            InputStream in = outputLine.getInputStream();
            byte[] ba = new byte[8];
            int anz = in.read( ba );

            long l = 0;
            for ( int i = 0; (i < ba.length) && (i < 8); i++ ) {
                l |= (((long) ba[i]) << (i << 3)) & (255L << (i << 3));
            }
            return l;
        } catch ( SocketTimeoutException e ) {
            throw new Exception();
        }
    }

    /**
     * @return
     * @throws Exception
     */
    private int getInt() throws Exception {
        try {
            InputStream in = outputLine.getInputStream();
            byte[] ba = new byte[4];
            int anz = in.read( ba );
            return (ba[0] << 24) + ((ba[1] & 0xFF) << 16) + ((ba[2] & 0xFF) << 8) + (ba[3] & 0xFF);
        } catch ( SocketTimeoutException e ) {
        }
        return 0;

    }

    /**
     * @return
     * @throws Exception
     */
    private byte getByte() throws Exception {
        try {
            InputStream in = outputLine.getInputStream();
            byte[] b = new byte[1];
            in.read( b );
            return b[0];
        } catch ( SocketTimeoutException e ) {
        }
        return 0;
    }

    /**
     * @return
     */
    public String readData(int anz) {
        String res = "";
        if ( outputLine != null && outputLine.isConnected() ) {
            try {
                InputStream g = outputLine.getInputStream();
                // länge des Strings
                if ( anz > 0 ) {
                    byte[] in = new byte[anz];
                    g.read( in );
                    res = new String( in, "ISO-8859-1" );
                }
                return res;
            } catch ( Exception e ) {
                e.printStackTrace();
                return null;
            }
        }
        return null;
    }

    /**
     * Send Byte
     * @param by
     */
    private void sendByte(byte by) {
        if ( outputLine != null && outputLine.isConnected() ) {
            try {
                outputLine.getOutputStream().write( new byte[] { by } );
            } catch ( IOException e ) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Send Integer
     * @param in
     */
    private void sendInt(int in) {
        if ( outputLine != null && outputLine.isConnected() ) {
            try {
                outputLine.getOutputStream().write( new byte[] { (byte) (in >>> 24), (byte) (in >>> 16), (byte) (in >>> 8), (byte) in } );
            } catch ( IOException e ) {
                e.printStackTrace();
            }
        }
    }

    /**
     * Send Data (String)
     * @param data
     */
    public void sendData(String data) {
        if ( outputLine != null && outputLine.isConnected() ) {
            try {
                OutputStream os = outputLine.getOutputStream();
                os.write( data.getBytes() );
            } catch ( IOException e ) {
                e.printStackTrace();
            }
        }
    }
}