package org.freertr.clnt;

import org.freertr.addr.addrEmpty;
import org.freertr.addr.addrIP;
import org.freertr.addr.addrType;
import org.freertr.ifc.ifcDn;
import org.freertr.ifc.ifcNull;
import org.freertr.ifc.ifcUp;
import org.freertr.ip.ipFwdIface;
import org.freertr.pack.packHolder;
import org.freertr.prt.prtGenConn;
import org.freertr.prt.prtServP;
import org.freertr.prt.prtTmux;
import org.freertr.prt.prtUdp;
import org.freertr.util.bits;
import org.freertr.util.counter;
import org.freertr.util.logger;
import org.freertr.util.state;

/**
 * generic udp encapsulation (rfcXXXX) client
 *
 * @author matecsaba
 */
public class clntGue0 implements Comparable<clntGue0>, Runnable, prtServP, ifcDn {

    /**
     * create instance
     */
    public clntGue0() {
    }

    /**
     * port number
     */
    public final static int portNum = 6080;

    /**
     * header size
     */
    public final static int size = 4;

    /**
     * upper layer
     */
    public ifcUp upper = new ifcNull();

    /**
     * target of tunnel
     */
    public addrIP target = null;

    /**
     * remote port number
     */
    public int prtR;

    /**
     * local port number
     */
    public int prtL;

    /**
     * udp to use
     */
    public prtUdp udp;

    /**
     * source interface
     */
    public ipFwdIface fwdIfc = null;

    /**
     * sending ttl value, -1 means maps out
     */
    public int sendingTTL = 255;

    /**
     * sending tos value, -1 means maps out
     */
    public int sendingTOS = -1;

    /**
     * sending df value, -1 means maps out
     */
    public int sendingDFN = -1;

    /**
     * sending flow value, -1 means maps out
     */
    public int sendingFLW = -1;

    /**
     * counter
     */
    public counter cntr = new counter();

    private prtGenConn conn;

    private boolean working = true;

    public String toString() {
        return "gue0 to " + target;
    }

    public int compareTo(clntGue0 o) {
        return target.compareTo(o.target);
    }

    /**
     * get hw address
     *
     * @return hw address
     */
    public addrType getHwAddr() {
        return new addrEmpty();
    }

    /**
     * set filter
     *
     * @param promisc promiscous mode
     */
    public void setFilter(boolean promisc) {
    }

    /**
     * get state
     *
     * @return state
     */
    public state.states getState() {
        return state.states.up;
    }

    /**
     * close interface
     */
    public void closeDn() {
        clearState();
    }

    /**
     * flap interface
     */
    public void flapped() {
        clearState();
    }

    /**
     * set upper layer
     *
     * @param server upper layer
     */
    public void setUpper(ifcUp server) {
        upper = server;
        upper.setParent(this);
    }

    /**
     * get counter
     *
     * @return counter
     */
    public counter getCounter() {
        return cntr;
    }

    /**
     * get mtu size
     *
     * @return mtu size
     */
    public int getMTUsize() {
        return 1400;
    }

    /**
     * get bandwidth
     *
     * @return bandwidth
     */
    public long getBandwidth() {
        return 4000000;
    }

    /**
     * send packet
     *
     * @param pck packet
     */
    public void sendPack(packHolder pck) {
        if (conn == null) {
            return;
        }
        int i = pck.msbGetW(0); // ethertype
        pck.getSkip(2);
        i = prtTmux.ethtyp2proto(i);
        if (i < 0) {
            cntr.drop(pck, counter.reasons.badProto);
            return;
        }
        pck.putByte(0, 0); // version
        pck.putByte(1, i); // protocol
        pck.msbPutW(2, 0); // flags
        pck.putSkip(size);
        pck.merge2beg();
        cntr.tx(pck);
        pck.putDefaults();
        conn.send2net(pck);
    }

    /**
     * start connection
     */
    public void workStart() {
        new Thread(this).start();
    }

    /**
     * stop connection
     */
    public void workStop() {
        working = false;
        clearState();
    }

    public void run() {
        for (;;) {
            if (!working) {
                break;
            }
            try {
                clearState();
                workDoer();
            } catch (Exception e) {
                logger.traceback(e);
            }
            clearState();
            bits.sleep(1000);
        }
    }

    private void workDoer() {
        if (prtR == 0) {
            prtR = portNum;
        }
        if (prtL == 0) {
            prtL = prtR;
        }
        conn = udp.packetConnect(this, fwdIfc, prtL, target, prtR, "gue0", -1, null, -1, -1);
        if (conn == null) {
            return;
        }
        conn.timeout = 120000;
        conn.sendTOS = sendingTOS;
        conn.sendDFN = sendingDFN;
        conn.sendFLW = sendingFLW;
        conn.sendTTL = sendingTTL;
        for (;;) {
            bits.sleep(1000);
            if (!working) {
                return;
            }
            if (conn.txBytesFree() < 0) {
                return;
            }
        }
    }

    private void clearState() {
        if (conn != null) {
            conn.setClosing();
        }
    }

    /**
     * close interface
     *
     * @param ifc interface
     */
    public void closedInterface(ipFwdIface ifc) {
    }

    /**
     * accept connection
     *
     * @param id connection
     * @return false on success, true on error
     */
    public boolean datagramAccept(prtGenConn id) {
        return true;
    }

    /**
     * connection ready
     *
     * @param id connection
     */
    public void datagramReady(prtGenConn id) {
    }

    /**
     * close connection
     *
     * @param id connection
     */
    public void datagramClosed(prtGenConn id) {
    }

    /**
     * work connection
     *
     * @param id connection
     */
    public void datagramWork(prtGenConn id) {
    }

    /**
     * received error
     *
     * @param id connection
     * @param pck packet
     * @param rtr reporting router
     * @param err error happened
     * @param lab error label
     * @return false on success, true on error
     */
    public boolean datagramError(prtGenConn id, packHolder pck, addrIP rtr, counter.reasons err, int lab) {
        return false;
    }

    /**
     * notified that state changed
     *
     * @param id id number to reference connection
     * @param stat state
     * @return return false if successful, true if error happened
     */
    public boolean datagramState(prtGenConn id, state.states stat) {
        return false;
    }

    /**
     * received packet
     *
     * @param id connection
     * @param pck packet
     * @return false on success, true on error
     */
    public boolean datagramRecv(prtGenConn id, packHolder pck) {
        if (pck.getByte(0) != 0) { // version
            logger.info("got bad version from " + target);
            cntr.drop(pck, counter.reasons.badVer);
            return false;
        }
        int i = pck.getByte(1); // protocol
        i = prtTmux.proto2ethtyp(i);
        if (i < 0) {
            logger.info("got bad protocol from " + target);
            cntr.drop(pck, counter.reasons.badProto);
            return false;
        }
        if (pck.msbGetW(2) != 0) {
            logger.info("got bad flags from " + target);
            cntr.drop(pck, counter.reasons.badFlag);
            return false;
        }
        pck.getSkip(size);
        pck.msbPutW(0, i); // ethertypes
        pck.putSkip(2);
        pck.merge2beg();
        cntr.rx(pck);
        upper.recvPack(pck);
        return false;
    }

}
