/*

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 *  2. Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 *  3. Neither the name of the copyright holder nor the

 *     names of its contributors may be used to endorse or promote products

 *     derived from this software without specific prior written permission.

 *

 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

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 */

/**

 * @file

 *   This file implements the PAN ID Query Server.

 */

#include "panid_query_server.hpp"

#include "coap/coap_message.hpp"

#include "common/as_core_type.hpp"

#include "common/code_utils.hpp"

#include "common/debug.hpp"

#include "common/instance.hpp"

#include "common/locator_getters.hpp"

#include "common/log.hpp"

#include "meshcop/meshcop.hpp"

#include "meshcop/meshcop_tlvs.hpp"

#include "thread/thread_netif.hpp"

#include "thread/uri_paths.hpp"

namespace ot {

RegisterLogModule("MeshCoP");

PanIdQueryServer::PanIdQueryServer(Instance &aInstance)

    : InstanceLocator(aInstance)

    , mChannelMask(0)

    , mPanId(Mac::kPanIdBroadcast)

    , mTimer(aInstance)

{

}

template <>

void PanIdQueryServer::HandleTmf<kUriPanIdQuery>(Coap::Message &aMessage, const Ip6::MessageInfo &aMessageInfo)

{

    uint16_t         panId;

    Ip6::MessageInfo responseInfo(aMessageInfo);

    uint32_t         mask;

    VerifyOrExit(aMessage.IsPostRequest());

    VerifyOrExit((mask = MeshCoP::ChannelMaskTlv::GetChannelMask(aMessage)) != 0);

    SuccessOrExit(Tlv::Find<MeshCoP::PanIdTlv>(aMessage, panId));

    mChannelMask  = mask;

    mCommissioner = aMessageInfo.GetPeerAddr();

    mPanId        = panId;

    mTimer.Start(kScanDelay);

    if (aMessage.IsConfirmable() && !aMessageInfo.GetSockAddr().IsMulticast())

    {

        SuccessOrExit(Get<Tmf::Agent>().SendEmptyAck(aMessage, responseInfo));

        LogInfo("sent panid query response");

    }

exit:

    return;

}

void PanIdQueryServer::HandleScanResult(Mac::ActiveScanResult *aScanResult, void *aContext)

{

    static_cast<PanIdQueryServer *>(aContext)->HandleScanResult(aScanResult);

}

void PanIdQueryServer::HandleScanResult(Mac::ActiveScanResult *aScanResult)

{

    if (aScanResult != nullptr)

    {

        if (aScanResult->mPanId == mPanId)

        {

            mChannelMask |= 1 << aScanResult->mChannel;

        }

    }

    else if (mChannelMask != 0)

    {

        SendConflict();

    }

}

void PanIdQueryServer::SendConflict(void)

{

    Error                   error = kErrorNone;

    MeshCoP::ChannelMaskTlv channelMask;

    Tmf::MessageInfo        messageInfo(GetInstance());

    Coap::Message          *message;

    message = Get<Tmf::Agent>().NewPriorityConfirmablePostMessage(kUriPanIdConflict);

    VerifyOrExit(message != nullptr, error = kErrorNoBufs);

    channelMask.Init();

    channelMask.SetChannelMask(mChannelMask);

    SuccessOrExit(error = channelMask.AppendTo(*message));

    SuccessOrExit(error = Tlv::Append<MeshCoP::PanIdTlv>(*message, mPanId));

    messageInfo.SetSockAddrToRlocPeerAddrTo(mCommissioner);

    SuccessOrExit(error = Get<Tmf::Agent>().SendMessage(*message, messageInfo));

    LogInfo("sent panid conflict");

exit:

    FreeMessageOnError(message, error);

    MeshCoP::LogError("send panid conflict", error);

}

void PanIdQueryServer::HandleTimer(void)

{

    IgnoreError(Get<Mac::Mac>().ActiveScan(mChannelMask, 0, HandleScanResult, this));

    mChannelMask = 0;

}

} // namespace ot