/***************************************************************************
 *   Copyright (C) 2012 by                                                 *
 *   Joris Guisson <joris.guisson@gmail.com>                               *
 *                                                                         *
 *   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 2 of the License, or     *
 *   (at your option) 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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
 ***************************************************************************/

#include "rpcmsgfactory.h"
#include <util/log.h>
#include <util/error.h>
#include <util/functions.h>
#include <bcodec/bnode.h>
#include "rpcserver.h"
#include "dht.h"
#include "errmsg.h"
#include "pingreq.h"
#include "findnodereq.h"
#include "announcereq.h"
#include "pingrsp.h"
#include "findnodersp.h"
#include "getpeersrsp.h"
#include "announcersp.h"

using namespace bt;

namespace dht
{

RPCMsgFactory::RPCMsgFactory()
{

}

RPCMsgFactory::~RPCMsgFactory()
{

}

RPCMsg::Ptr RPCMsgFactory::buildRequest(BDictNode* dict)
{
    BDictNode* args = dict->getDict(ARG);
    if (!args)
        throw bt::Error("Invalid request, arguments missing");

    RPCMsg::Ptr msg;
    QString str = dict->getString(REQ, 0);
    if (str == "ping") {
        msg = RPCMsg::Ptr(new PingReq());
        msg->parse(dict);
        return msg;
    } else if (str == "find_node") {
        msg = RPCMsg::Ptr(new FindNodeReq());
        msg->parse(dict);
        return msg;
    } else if (str == "get_peers") {
        msg = RPCMsg::Ptr(new GetPeersReq());
        msg->parse(dict);
        return msg;
    } else if (str == "announce_peer") {
        msg = RPCMsg::Ptr(new AnnounceReq());
        msg->parse(dict);
        return msg;
    } else if (str == "vote") {
        // Some µTorrent extension to rate torrents, just ignore
        return msg;
    } else
        throw bt::Error(QString("Invalid request type %1").arg(str));
}


RPCMsg::Ptr RPCMsgFactory::buildResponse(BDictNode* dict, dht::RPCMethodResolver* method_resolver)
{
    BDictNode* args = dict->getDict(RSP);
    if (!args)
        throw bt::Error("Arguments missing for DHT response");

    QByteArray mtid = dict->getByteArray(TID);
    // check for empty byte arrays should prevent 144416
    if (mtid.size() == 0)
        throw bt::Error("Empty transaction ID in DHT response");

    RPCMsg::Ptr msg;

    // find the call
    Method method = method_resolver->findMethod(mtid);
    switch (method) {
    case PING:
        msg = RPCMsg::Ptr(new PingRsp());
        msg->parse(dict);
        break;
    case FIND_NODE:
        msg = RPCMsg::Ptr(new FindNodeRsp());
        msg->parse(dict);
        break;
    case GET_PEERS:
        msg = RPCMsg::Ptr(new GetPeersRsp());
        msg->parse(dict);
        break;
    case ANNOUNCE_PEER:
        msg = RPCMsg::Ptr(new AnnounceRsp());
        msg->parse(dict);
        break;
    case NONE:
    default:
        throw bt::Error(QString("Unknown DHT rpc call (transaction id = %1)").arg(mtid[0]));
    }

    return msg;
}


RPCMsg::Ptr RPCMsgFactory::build(bt::BDictNode* dict, RPCMethodResolver* method_resolver)
{
    QString t = dict->getString(TYP, 0);
    if (t == REQ) {
        return buildRequest(dict);
    } else if (t == RSP) {
        return buildResponse(dict, method_resolver);
    } else if (t == ERR_DHT) {
        RPCMsg::Ptr msg(new ErrMsg());
        msg->parse(dict);
        return msg;
    } else
        throw bt::Error(QString("Unknown message type %1").arg(t));
}

}
