/*
    This file is part of Peers.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    
    Copyright 2007, 2008 Yohann Martineau 
*/

package net.sourceforge.peers.sip.core.useragent.handlers;

import gov.nist.jrtp.RtpException;

import java.io.IOException;
import java.util.Hashtable;
import java.util.List;

import net.sourceforge.peers.Logger;
import net.sourceforge.peers.media.CaptureRtpSender;
import net.sourceforge.peers.media.IncomingRtpReader;
import net.sourceforge.peers.sdp.NoCodecException;
import net.sourceforge.peers.sdp.SDPManager;
import net.sourceforge.peers.sdp.SessionDescription;
import net.sourceforge.peers.sip.RFC3261;
import net.sourceforge.peers.sip.Utils;
import net.sourceforge.peers.sip.core.useragent.MidDialogRequestManager;
import net.sourceforge.peers.sip.core.useragent.SipEvent;
import net.sourceforge.peers.sip.core.useragent.UserAgent;
import net.sourceforge.peers.sip.core.useragent.SipEvent.EventType;
import net.sourceforge.peers.sip.syntaxencoding.NameAddress;
import net.sourceforge.peers.sip.syntaxencoding.SipHeaderFieldName;
import net.sourceforge.peers.sip.syntaxencoding.SipHeaderFieldValue;
import net.sourceforge.peers.sip.syntaxencoding.SipHeaderParamName;
import net.sourceforge.peers.sip.syntaxencoding.SipHeaders;
import net.sourceforge.peers.sip.syntaxencoding.SipURI;
import net.sourceforge.peers.sip.transaction.ClientTransaction;
import net.sourceforge.peers.sip.transaction.ClientTransactionUser;
import net.sourceforge.peers.sip.transaction.InviteServerTransaction;
import net.sourceforge.peers.sip.transaction.ServerTransaction;
import net.sourceforge.peers.sip.transaction.ServerTransactionUser;
import net.sourceforge.peers.sip.transaction.Transaction;
import net.sourceforge.peers.sip.transaction.TransactionManager;
import net.sourceforge.peers.sip.transactionuser.Dialog;
import net.sourceforge.peers.sip.transactionuser.DialogManager;
import net.sourceforge.peers.sip.transport.MessageSender;
import net.sourceforge.peers.sip.transport.SipRequest;
import net.sourceforge.peers.sip.transport.SipResponse;
import net.sourceforge.peers.sip.transport.TransportManager;

public class InviteHandler extends DialogMethodHandler
        implements ServerTransactionUser, ClientTransactionUser {

    //TODO move sdp manager, this should probably be in UserAgent
    private SDPManager sdpManager;
    
    public InviteHandler() {
        sdpManager = new SDPManager();
    }
    
    
    //////////////////////////////////////////////////////////
    // UAS methods
    //////////////////////////////////////////////////////////

    public void handleInitialInvite(SipRequest sipRequest) {
        
//        setChanged();
//        ArrayList args = new ArrayList();
//        args.add(Event.incomingCall);
//        args.add(sipRequest);
//        
//        notifyObservers(args);
        
        //generate 180 Ringing
        SipResponse sipResponse = buildGenericResponse(sipRequest,
                RFC3261.CODE_180_RINGING, RFC3261.REASON_180_RINGING);
        Dialog dialog = buildDialogForUas(sipResponse, sipRequest);
        //here dialog is already stored in dialogs in DialogManager
        
        InviteServerTransaction inviteServerTransaction = (InviteServerTransaction)
            TransactionManager.getInstance().createServerTransaction(sipResponse,
                    Utils.getInstance().getSipPort(), RFC3261.TRANSPORT_UDP, this,
                    sipRequest);
        
        inviteServerTransaction.start();
        
        inviteServerTransaction.receivedRequest(sipRequest);
        
        //TODO send 180 more than once
        inviteServerTransaction.sendReponse(sipResponse);

        setChanged();
        notifyObservers(new SipEvent(EventType.INCOMING_CALL, sipResponse));

        dialog.receivedOrSent1xx();

        List<String> peers = UserAgent.getInstance().getPeers();
        String responseTo = sipRequest.getSipHeaders().get(
                new SipHeaderFieldName(RFC3261.HDR_FROM)).getValue();
        if (!peers.contains(responseTo)) {
            peers.add(responseTo);
        }
        
    }
    
    public void handleReInvite(SipRequest sipRequest) {
        
    }
    
    public void acceptCall(SipRequest sipRequest, Dialog dialog) {
        SipHeaders reqHeaders = sipRequest.getSipHeaders();
        SipHeaderFieldValue contentType =
            reqHeaders.get(new SipHeaderFieldName(RFC3261.HDR_CONTENT_TYPE));
        
        
        if (RFC3261.CONTENT_TYPE_SDP.equals(contentType)) {
            //TODO
//            String sdpResponse;
//            try {
//                sdpResponse = sdpManager.handleOffer(
//                        new String(sipRequest.getBody()));
//            } catch (NoCodecException e) {
//                sdpResponse = sdpManager.generateErrorResponse();
//            }
        } else {
            // TODO manage empty bodies and non-application/sdp content type
        }


        //TODO if mode autoanswer just send 200 without asking any question
        SipResponse sipResponse =
            MidDialogRequestManager.generateMidDialogResponse(
                    sipRequest,
                    dialog,
                    RFC3261.CODE_200_OK,
                    RFC3261.REASON_200_OK);
        
        // TODO 13.3 dialog invite-specific processing
        
        // TODO timer if there is an Expires header in INVITE
        
        // TODO 3xx
        
        // TODO 486 or 600
        
        String body;
        if (sipRequest.getBody() != null
                && RFC3261.CONTENT_TYPE_SDP.equals(contentType.getValue())) {
            // create response in 200
            try {
                body = sdpManager.handleOffer(sipRequest.getBody());
            } catch (NoCodecException e) {
                body = sdpManager.generateErrorResponse();
            }
        } else {
            // create offer in 200
            body = sdpManager.generateOffer();
        }
        sipResponse.setBody(body.getBytes());
        SipHeaders respHeaders = sipResponse.getSipHeaders();
        respHeaders.add(new SipHeaderFieldName(RFC3261.HDR_CONTENT_TYPE),
                new SipHeaderFieldValue(RFC3261.CONTENT_TYPE_SDP));
        
        
        // TODO determine port and transport for server transaction>transport
        // from initial invite
        // FIXME determine port and transport for server transaction>transport
        ServerTransaction serverTransaction =
            TransactionManager.getInstance().getServerTransaction(sipRequest);
        
        serverTransaction.start();
        
        serverTransaction.receivedRequest(sipRequest);
        
        serverTransaction.sendReponse(sipResponse);
        // TODO manage retransmission of the response (send to the transport)
        // until ACK arrives, if no ACK is received within 64*T1, confirm dialog
        // and terminate it with a BYE

//        Logger.getInstance().debug("before dialog.receivedOrSent2xx();");
//        Logger.getInstance().debug("dialog state: " + dialog.getState());
        
        dialog.receivedOrSent2xx();
//        Logger.getInstance().debug("dialog state: " + dialog.getState());
//        Logger.getInstance().debug("after dialog.receivedOrSent2xx();");
        
//        setChanged();
//        notifyObservers(sipRequest);
    }
    
    public void rejectCall(SipRequest sipRequest) {
        //TODO generate 486, etc.
        SipHeaders reqHeaders = sipRequest.getSipHeaders();
        SipHeaderFieldValue to = reqHeaders.get(
                new SipHeaderFieldName(RFC3261.HDR_FROM));
        String remoteUri = to.getValue();
        if (remoteUri.indexOf(RFC3261.LEFT_ANGLE_BRACKET) > -1) {
            remoteUri = NameAddress.nameAddressToUri(remoteUri);
        }
        Dialog dialog = DialogManager.getInstance().getDialog(remoteUri);
        
        //TODO manage auto reject Do not disturb (DND)
        SipResponse sipResponse =
            MidDialogRequestManager.generateMidDialogResponse(
                    sipRequest,
                    dialog,
                    RFC3261.CODE_486_BUSYHERE,
                    RFC3261.REASON_486_BUSYHERE);
        
        // TODO determine port and transport for server transaction>transport
        // from initial invite
        // FIXME determine port and transport for server transaction>transport
        ServerTransaction serverTransaction =
            TransactionManager.getInstance().getServerTransaction(sipRequest);
        
        serverTransaction.start();
        
        serverTransaction.receivedRequest(sipRequest);
        
        serverTransaction.sendReponse(sipResponse);
        
        dialog.receivedOrSent300To699();
        
//        setChanged();
//        notifyObservers(sipRequest);
    }
    
    //////////////////////////////////////////////////////////
    // UAC methods
    //////////////////////////////////////////////////////////
    
    public ClientTransaction preProcessInvite(SipRequest sipRequest) {