/*

 *  Copyright (c) 2017, The OpenThread Authors.

 *  All rights reserved.

 *

 *  Redistribution and use in source and binary forms, with or without

 *  modification, are permitted provided that the following conditions are met:

 *  1. Redistributions of source code must retain the above copyright

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

 *  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

 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 *  POSSIBILITY OF SUCH DAMAGE.

 */

/**

 * @file

 *   This file implements a simple CLI for the CoAP service.

 */

#include "cli_coap.hpp"

#if OPENTHREAD_CONFIG_COAP_API_ENABLE

#include <openthread/random_noncrypto.h>

#include <ctype.h>

#include "cli/cli.hpp"

namespace ot {

namespace Cli {

Coap::Coap(otInstance *aInstance, OutputImplementer &aOutputImplementer)

    : Utils(aInstance, aOutputImplementer)

    , mUseDefaultRequestTxParameters(true)

    , mUseDefaultResponseTxParameters(true)

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    , mObserveSerial(0)

    , mRequestTokenLength(0)

    , mSubscriberTokenLength(0)

    , mSubscriberConfirmableNotifications(false)

#endif

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    , mBlockCount(1)

#endif

{

    ClearAllBytes(mResource);

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    ClearAllBytes(mRequestAddr);

    ClearAllBytes(mSubscriberSock);

    ClearAllBytes(mRequestToken);

    ClearAllBytes(mSubscriberToken);

    ClearAllBytes(mRequestUri);

#endif

    ClearAllBytes(mUriPath);

    strncpy(mResourceContent, "0", sizeof(mResourceContent));

    mResourceContent[sizeof(mResourceContent) - 1] = '\0';

}

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

otError Coap::CancelResourceSubscription(void)

{

    otError       error   = OT_ERROR_NONE;

    otMessage    *message = nullptr;

    otMessageInfo messageInfo;

    ClearAllBytes(messageInfo);

    messageInfo.mPeerAddr = mRequestAddr;

    messageInfo.mPeerPort = OT_DEFAULT_COAP_PORT;

    VerifyOrExit(mRequestTokenLength != 0, error = OT_ERROR_INVALID_STATE);

    message = otCoapNewMessage(GetInstancePtr(), nullptr);

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

    otCoapMessageInit(message, OT_COAP_TYPE_CONFIRMABLE, OT_COAP_CODE_GET);

    SuccessOrExit(error = otCoapMessageSetToken(message, mRequestToken, mRequestTokenLength));

    SuccessOrExit(error = otCoapMessageAppendObserveOption(message, 1));

    SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, mRequestUri));

    SuccessOrExit(error = otCoapSendRequest(GetInstancePtr(), message, &messageInfo, &Coap::HandleResponse, this));

    ClearAllBytes(mRequestAddr);

    ClearAllBytes(mRequestUri);

    mRequestTokenLength = 0;

exit:

    if ((error != OT_ERROR_NONE) && (message != nullptr))

    {

        otMessageFree(message);

    }

    return error;

}

void Coap::CancelSubscriber(void)

{

    ClearAllBytes(mSubscriberSock);

    mSubscriberTokenLength = 0;

}

#endif // OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

void Coap::PrintPayload(otMessage *aMessage)

{

    uint8_t  buf[kMaxBufferSize];

    uint16_t bytesToPrint;

    uint16_t bytesPrinted = 0;

    uint16_t length       = otMessageGetLength(aMessage) - otMessageGetOffset(aMessage);

    if (length > 0)

    {

        OutputFormat(" with payload: ");

        while (length > 0)

        {

            bytesToPrint = Min(length, static_cast<uint16_t>(sizeof(buf)));

            otMessageRead(aMessage, otMessageGetOffset(aMessage) + bytesPrinted, buf, bytesToPrint);

            OutputBytes(buf, static_cast<uint8_t>(bytesToPrint));

            length -= bytesToPrint;

            bytesPrinted += bytesToPrint;

        }

    }

    OutputNewLine();

}

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

/**

 * @cli coap cancel

 * @code

 * coap cancel

 * Done

 * @endcode

 * @par

 * Cancels an existing observation subscription to a remote resource on the CoAP server.

 * @note This command is available only when `OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE` is set.

 * @csa{coap observe}

 */

template <> otError Coap::Process<Cmd("cancel")>(Arg aArgs[])

{

    OT_UNUSED_VARIABLE(aArgs);

    return CancelResourceSubscription();

}

#endif

/**

 * @cli coap resource (get,set)

 * @code

 * coap resource test-resource

 * Done

 * @endcode

 * @code

 * coap resource

 * test-resource

 * Done

 * @endcode

 * @cparam coap resource [@ca{uri-path}]

 * @par

 * Gets or sets the URI path of the CoAP server resource.

 * @sa otCoapAddResource

 * @sa otCoapAddBlockWiseResource

 */

template <> otError Coap::Process<Cmd("resource")>(Arg aArgs[])

{

    otError error = OT_ERROR_NONE;

    if (!aArgs[0].IsEmpty())

    {

        VerifyOrExit(aArgs[0].GetLength() < kMaxUriLength, error = OT_ERROR_INVALID_ARGS);

        mResource.mUriPath = mUriPath;

        mResource.mContext = this;

        mResource.mHandler = &Coap::HandleRequest;

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        mResource.mReceiveHook  = &Coap::BlockwiseReceiveHook;

        mResource.mTransmitHook = &Coap::BlockwiseTransmitHook;

        if (!aArgs[1].IsEmpty())

        {

            SuccessOrExit(error = aArgs[1].ParseAsUint32(mBlockCount));

        }

#endif

        strncpy(mUriPath, aArgs[0].GetCString(), sizeof(mUriPath) - 1);

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        otCoapAddBlockWiseResource(GetInstancePtr(), &mResource);

#else

        otCoapAddResource(GetInstancePtr(), &mResource);

#endif

    }

    else

    {

        OutputLine("%s", mResource.mUriPath != nullptr ? mResource.mUriPath : "");

    }

exit:

    return error;

}

/**

 * @cli coap set

 * @code

 * coap set Testing123

 * Done

 * @endcode

 * @cparam coap set @ca{new-content}

 * @par

 * Sets the content sent by the resource on the CoAP server.

 * If a CoAP client is observing the resource, a notification is sent to that client.

 * @csa{coap observe}

 * @sa otCoapMessageInit

 * @sa otCoapNewMessage

 */

template <> otError Coap::Process<Cmd("set")>(Arg aArgs[])

{

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    otMessage    *notificationMessage = nullptr;

    otMessageInfo messageInfo;

#endif

    otError error = OT_ERROR_NONE;

    if (!aArgs[0].IsEmpty())

    {

        VerifyOrExit(aArgs[0].GetLength() < sizeof(mResourceContent), error = OT_ERROR_INVALID_ARGS);

        strncpy(mResourceContent, aArgs[0].GetCString(), sizeof(mResourceContent));

        mResourceContent[sizeof(mResourceContent) - 1] = '\0';

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        if (mSubscriberTokenLength > 0)

        {

            // Notify the subscriber

            ClearAllBytes(messageInfo);

            messageInfo.mPeerAddr = mSubscriberSock.mAddress;

            messageInfo.mPeerPort = mSubscriberSock.mPort;

            OutputFormat("sending coap notification to ");

            OutputIp6AddressLine(mSubscriberSock.mAddress);

            notificationMessage = otCoapNewMessage(GetInstancePtr(), nullptr);

            VerifyOrExit(notificationMessage != nullptr, error = OT_ERROR_NO_BUFS);

            otCoapMessageInit(

                notificationMessage,

                ((mSubscriberConfirmableNotifications) ? OT_COAP_TYPE_CONFIRMABLE : OT_COAP_TYPE_NON_CONFIRMABLE),

                OT_COAP_CODE_CONTENT);

            SuccessOrExit(error = otCoapMessageSetToken(notificationMessage, mSubscriberToken, mSubscriberTokenLength));

            SuccessOrExit(error = otCoapMessageAppendObserveOption(notificationMessage, mObserveSerial++));

            SuccessOrExit(error = otCoapMessageSetPayloadMarker(notificationMessage));

            SuccessOrExit(error = otMessageAppend(notificationMessage, mResourceContent,

                                                  static_cast<uint16_t>(strlen(mResourceContent))));

            SuccessOrExit(error = otCoapSendRequest(GetInstancePtr(), notificationMessage, &messageInfo,

                                                    &Coap::HandleNotificationResponse, this));

        }

#endif // OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    }

    else

    {

        OutputLine("%s", mResourceContent);

    }

exit:

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    if ((error != OT_ERROR_NONE) && (notificationMessage != nullptr))

    {

        otMessageFree(notificationMessage);

    }

#endif

    return error;

}

/**

 * @cli coap start

 * @code

 * coap start

 * Done

 * @endcode

 * @par

 * Starts the CoAP server. @moreinfo{@coap}.

 * @sa otCoapStart

 */

template <> otError Coap::Process<Cmd("start")>(Arg aArgs[])

{

    OT_UNUSED_VARIABLE(aArgs);

    return otCoapStart(GetInstancePtr(), OT_DEFAULT_COAP_PORT);

}

/**

 * @cli coap stop

 * @code

 * coap stop

 * Done

 * @endcode

 * @par api_copy

 * #otCoapStop

 */

template <> otError Coap::Process<Cmd("stop")>(Arg aArgs[])

{

    OT_UNUSED_VARIABLE(aArgs);

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    otCoapRemoveBlockWiseResource(GetInstancePtr(), &mResource);

#else

    otCoapRemoveResource(GetInstancePtr(), &mResource);

#endif

    return otCoapStop(GetInstancePtr());

}

/**

 * @cli coap parameters(get,set)

 * @code

 * coap parameters request

 * Transmission parameters for request:

 * ACK_TIMEOUT=1000 ms, ACK_RANDOM_FACTOR=255/254, MAX_RETRANSMIT=2

 * Done

 * @endcode

 * @code

 * coap parameters request default

 * Transmission parameters for request:

 * default

 * Done

 * @endcode

 * @code

 * coap parameters request 1000 255 254 2

 * Transmission parameters for request:

 * ACK_TIMEOUT=1000 ms, ACK_RANDOM_FACTOR=255/254, MAX_RETRANSMIT=2

 * Done

 * @endcode

 * @cparam coap parameters @ca{type} [@ca{default} | <!--

 * -->@ca{ack_timeout ack_random_factor_numerator <!--

 * -->ack_random_factor_denominator max_retransmit}]

 *   * `type`: `request` for CoAP requests, or `response` for CoAP responses.

        If no more parameters are given, the command prints the current configuration.

 *   * `default`: Sets the transmission parameters to

        the following default values:

 *       * `ack_timeout`: 2000 milliseconds

 *       * `ack_random_factor_numerator`: 3

 *       * `ack_random_factor_denominator`: 2

 *       * `max_retransmit`: 4

 *   * `ack_timeout`: The `ACK_TIMEOUT` (0-UINT32_MAX) in milliseconds.

       Refer to RFC7252.

 *   * `ack_random_factor_numerator`:

       The `ACK_RANDOM_FACTOR` numerator, with possible values

       of 0-255. Refer to RFC7252.

 *   * `ack_random_factor_denominator`:

 *     The `ACK_RANDOM_FACTOR` denominator, with possible values

 *     of 0-255. Refer to RFC7252.

 *   * `max_retransmit`: The `MAX_RETRANSMIT` (0-255). Refer to RFC7252.

 * @par

 * Gets current CoAP parameter values if the command is run with no optional

 * parameters.

 * @par

 * Sets the CoAP parameters either to their default values or to the values

 * you specify, depending on the syntax chosen.

 */

template <> otError Coap::Process<Cmd("parameters")>(Arg aArgs[])

{

    otError             error = OT_ERROR_NONE;

    bool               *defaultTxParameters;

    otCoapTxParameters *txParameters;

    if (aArgs[0] == "request")

    {

        txParameters        = &mRequestTxParameters;

        defaultTxParameters = &mUseDefaultRequestTxParameters;

    }

    else if (aArgs[0] == "response")

    {

        txParameters        = &mResponseTxParameters;

        defaultTxParameters = &mUseDefaultResponseTxParameters;

    }

    else

    {

        ExitNow(error = OT_ERROR_INVALID_ARGS);

    }

    if (!aArgs[1].IsEmpty())

    {

        if (aArgs[1] == "default")

        {

            *defaultTxParameters = true;

        }

        else

        {

            SuccessOrExit(error = aArgs[1].ParseAsUint32(txParameters->mAckTimeout));

            SuccessOrExit(error = aArgs[2].ParseAsUint8(txParameters->mAckRandomFactorNumerator));

            SuccessOrExit(error = aArgs[3].ParseAsUint8(txParameters->mAckRandomFactorDenominator));

            SuccessOrExit(error = aArgs[4].ParseAsUint8(txParameters->mMaxRetransmit));

            VerifyOrExit(txParameters->mAckRandomFactorNumerator > txParameters->mAckRandomFactorDenominator,

                         error = OT_ERROR_INVALID_ARGS);

            *defaultTxParameters = false;

        }

    }

    OutputLine("Transmission parameters for %s:", aArgs[0].GetCString());

    if (*defaultTxParameters)

    {

        OutputLine("default");

    }

    else

    {

        OutputLine("ACK_TIMEOUT=%lu ms, ACK_RANDOM_FACTOR=%u/%u, MAX_RETRANSMIT=%u", ToUlong(txParameters->mAckTimeout),

                   txParameters->mAckRandomFactorNumerator, txParameters->mAckRandomFactorDenominator,

                   txParameters->mMaxRetransmit);

    }

exit:

    return error;

}

/**

 * @cli coap get

 * @code

 * coap get fdde:ad00:beef:0:2780:9423:166c:1aac test-resource

 * Done

 * @endcode

 * @code

 * coap get fdde:ad00:beef:0:2780:9423:166c:1aac test-resource block-1024

 * Done

 * @endcode

 * @cparam coap get @ca{address} @ca{uri-path} [@ca{type}]

 *   * `address`: IPv6 address of the CoAP server.

 *   * `uri-path`: URI path of the resource.

 *   * `type`:

 *       * `con`: Confirmable

 *       * `non-con`: Non-confirmable (default)

 *       * `block-`: Use this option, followed by the block-wise value,

 *          if the response should be transferred block-wise. Valid

 *          values are: `block-16`, `block-32`, `block-64`, `block-128`,

 *          `block-256`, `block-512`, or `block-1024`.

 * @par

 * Gets information about the specified CoAP resource on the CoAP server.

 */

template <> otError Coap::Process<Cmd("get")>(Arg aArgs[]) { return ProcessRequest(aArgs, OT_COAP_CODE_GET); }

/**

 * @cli coap post

 * @code

 * coap post fdde:ad00:beef:0:2780:9423:166c:1aac test-resource con hellothere

 * Done

 * @endcode

 * @code

 * coap post fdde:ad00:beef:0:2780:9423:166c:1aac test-resource block-1024 10

 * Done

 * @endcode

 * @cparam coap post @ca{address} @ca{uri-path} [@ca{type}] [@ca{payload}]

 *   * `address`: IPv6 address of the CoAP server.

 *   * `uri-path`: URI path of the resource.

 *   * `type`:

 *         * `con`: Confirmable

 *         * `non-con`: Non-confirmable (default)

 *         * `block-`: Use this option, followed by the block-wise value,

 *            to send blocks with a randomly generated number of bytes

 *            for the payload. Valid values are:

 *            `block-16`, `block-32`, `block-64`, `block-128`,

 *            `block-256`, `block-512`, or `block-1024`.

 *   * `payload`: CoAP payload request, which if used is either a string or an

 *     integer, depending on the `type`. If the `type` is `con` or `non-con`,

 *     the `payload` parameter is optional. If you leave out the

 *     `payload` parameter, an empty payload is sent. However, If you use the

 *     `payload` parameter, its value must be a string, such as

 *     `hellothere`.  If the `type` is `block-`,

 *     the value of the`payload` parameter must be an integer that specifies

 *     the number of blocks to send. The `block-` type requires

 *     `OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE` to be set.

 * @par

 * Creates the specified CoAP resource. @moreinfo{@coap}.

 */

template <> otError Coap::Process<Cmd("post")>(Arg aArgs[]) { return ProcessRequest(aArgs, OT_COAP_CODE_POST); }

/**

 * @cli coap put

 * @code

 * coap put fdde:ad00:beef:0:2780:9423:166c:1aac test-resource con hellothere

 * Done

 * @endcode

 * @code

 * coap put fdde:ad00:beef:0:2780:9423:166c:1aac test-resource block-1024 10

 * Done

 * @endcode

 * @cparam coap put @ca{address} @ca{uri-path} [@ca{type}] [@ca{payload}]

 *   * `address`: IPv6 address of the CoAP server.

 *   * `uri-path`: URI path of the resource.

 *   * `type`:

 *         * `con`: Confirmable

 *         * `non-con`: Non-confirmable (default)

 *         * `block-`: Use this option, followed by the block-wise value,

 *            to send blocks with a randomly generated number of bytes

 *            for the payload. Valid values are:

 *            `block-16`, `block-32`, `block-64`, `block-128`,

 *            `block-256`, `block-512`, or `block-1024`.

 *   * `payload`: CoAP payload request, which if used is either a string or an

 *     integer, depending on the `type`. If the `type` is `con` or `non-con`,

 *     the `payload` parameter is optional. If you leave out the

 *     `payload` parameter, an empty payload is sent. However, If you use the

 *     `payload` parameter, its value must be a string, such as

 *     `hellothere`. If the `type` is `block-`,

 *     the value of the`payload` parameter must be an integer that specifies

 *     the number of blocks to send. The `block-` type requires

 *     `OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE` to be set.

 * @par

 * Modifies the specified CoAP resource. @moreinfo{@coap}.

 */

template <> otError Coap::Process<Cmd("put")>(Arg aArgs[]) { return ProcessRequest(aArgs, OT_COAP_CODE_PUT); }

/**

 * @cli coap delete

 * @code

 * coap delete fdde:ad00:beef:0:2780:9423:166c:1aac test-resource con hellothere

 * Done

 * @endcode

 * @cparam coap delete @ca{address} @ca{uri-path} [@ca{type}] [@ca{payload}]

 *   * `address`: IPv6 address of the CoAP server.

 *   * `uri-path`: URI path of the resource.

 *   * `type`:

 *       * `con`: Confirmable

 *       * `non-con`: Non-confirmable (default)

 *   * `payload`: The CoAP payload string. For example, `hellothere`.

 *  @par

 *  Deletes the specified CoAP resource.

 */

template <> otError Coap::Process<Cmd("delete")>(Arg aArgs[]) { return ProcessRequest(aArgs, OT_COAP_CODE_DELETE); }

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

/**

 * @cli coap observe

 * @code

 * coap observe fdde:ad00:beef:0:2780:9423:166c:1aac test-resource

 * Done

 * @endcode

 * @cparam coap observe @ca{address} @ca{uri-path} [@ca{type}]

 *   * `address`: IPv6 address of the CoAP server.

 *   * `uri-path`: URI path of the resource.

 *   * `type`:

 *       * `con`: Confirmable

 *       * `non-con`: Non-confirmable (default).

 * @par

 * Triggers a subscription request which allows the CoAP client to

 * observe the specified resource on the CoAP server for possible changes

 * in its state.

 * @note This command is available only when `OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE` is set.

 */

template <> otError Coap::Process<Cmd("observe")>(Arg aArgs[])

{

    return ProcessRequest(aArgs, OT_COAP_CODE_GET, /* aCoapObserve */ true);

}

#endif

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

otError Coap::ProcessRequest(Arg aArgs[], otCoapCode aCoapCode, bool aCoapObserve)

#else

otError Coap::ProcessRequest(Arg aArgs[], otCoapCode aCoapCode)

#endif

{

    otError       error   = OT_ERROR_NONE;

    otMessage    *message = nullptr;

    otMessageInfo messageInfo;

    uint16_t      payloadLength    = 0;

    char         *uriQueryStartPtr = nullptr;

    // Default parameters

    char         coapUri[kMaxUriLength] = "test";

    otCoapType   coapType               = OT_COAP_TYPE_NON_CONFIRMABLE;

    otIp6Address coapDestinationIp;

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    bool           coapBlock     = false;

    otCoapBlockSzx coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_16;

    BlockType      coapBlockType = (aCoapCode == OT_COAP_CODE_GET) ? kBlockType2 : kBlockType1;

#endif

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE && OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    if (aCoapObserve)

    {

        coapBlockType = kBlockType1;

    }

#endif

    SuccessOrExit(error = aArgs[0].ParseAsIp6Address(coapDestinationIp));

    VerifyOrExit(!aArgs[1].IsEmpty(), error = OT_ERROR_INVALID_ARGS);

    VerifyOrExit(aArgs[1].GetLength() < sizeof(coapUri), error = OT_ERROR_INVALID_ARGS);

    strcpy(coapUri, aArgs[1].GetCString());

    // CoAP-Type

    if (!aArgs[2].IsEmpty())

    {

        if (aArgs[2] == "con")

        {

            coapType = OT_COAP_TYPE_CONFIRMABLE;

        }

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        else if (aArgs[2] == "block-16")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_16;

        }

        else if (aArgs[2] == "block-32")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_32;

        }

        else if (aArgs[2] == "block-64")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_64;

        }

        else if (aArgs[2] == "block-128")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_128;

        }

        else if (aArgs[2] == "block-256")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_256;

        }

        else if (aArgs[2] == "block-512")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_512;

        }

        else if (aArgs[2] == "block-1024")

        {

            coapType      = OT_COAP_TYPE_CONFIRMABLE;

            coapBlock     = true;

            coapBlockSize = OT_COAP_OPTION_BLOCK_SZX_1024;

        }

#endif // OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    }

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    if (aCoapObserve && mRequestTokenLength)

    {

        // New observe request, cancel any existing observation

        SuccessOrExit(error = CancelResourceSubscription());

    }

#endif

    message = otCoapNewMessage(GetInstancePtr(), nullptr);

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

    otCoapMessageInit(message, coapType, aCoapCode);

    otCoapMessageGenerateToken(message, OT_COAP_DEFAULT_TOKEN_LENGTH);

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    if (aCoapObserve)

    {

        SuccessOrExit(error = otCoapMessageAppendObserveOption(message, 0));

    }

#endif

    uriQueryStartPtr = const_cast<char *>(StringFind(coapUri, '?'));

    if (uriQueryStartPtr == nullptr)

    {

        // "?" doesn't present in URI --> contains only URI path parts

        SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, coapUri));

    }

    else

    {

        // "?" presents in URI --> contains URI path AND URI query parts

        *uriQueryStartPtr++ = '\0';

        SuccessOrExit(error = otCoapMessageAppendUriPathOptions(message, coapUri));

        SuccessOrExit(error = otCoapMessageAppendUriQueryOptions(message, uriQueryStartPtr));

    }

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    if (coapBlock)

    {

        if (coapBlockType == kBlockType1)

        {

            SuccessOrExit(error = otCoapMessageAppendBlock1Option(message, 0, true, coapBlockSize));

        }

        else

        {

            SuccessOrExit(error = otCoapMessageAppendBlock2Option(message, 0, false, coapBlockSize));

        }

    }

#endif

    if (!aArgs[3].IsEmpty())

    {

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        if (coapBlock)

        {

            SuccessOrExit(error = aArgs[3].ParseAsUint32(mBlockCount));

        }

        else

        {

#endif

            payloadLength = aArgs[3].GetLength();

            if (payloadLength > 0)

            {

                SuccessOrExit(error = otCoapMessageSetPayloadMarker(message));

            }

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        }

#endif

    }

    // Embed content into message if given

    if (payloadLength > 0)

    {

        SuccessOrExit(error = otMessageAppend(message, aArgs[3].GetCString(), payloadLength));

    }

    ClearAllBytes(messageInfo);

    messageInfo.mPeerAddr = coapDestinationIp;

    messageInfo.mPeerPort = OT_DEFAULT_COAP_PORT;

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    if (aCoapObserve)

    {

        // Make a note of the message details for later so we can cancel it later.

        memcpy(&mRequestAddr, &coapDestinationIp, sizeof(mRequestAddr));

        mRequestTokenLength = otCoapMessageGetTokenLength(message);

        memcpy(mRequestToken, otCoapMessageGetToken(message), mRequestTokenLength);

        // Use `memcpy` instead of `strncpy` here because GCC will give warnings for `strncpy` when the dest's length is

        // not bigger than the src's length.

        memcpy(mRequestUri, coapUri, sizeof(mRequestUri) - 1);

    }

#endif

    if ((coapType == OT_COAP_TYPE_CONFIRMABLE) || (aCoapCode == OT_COAP_CODE_GET))

    {

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        if (coapBlock)

        {

            if (aCoapCode == OT_COAP_CODE_PUT || aCoapCode == OT_COAP_CODE_POST)

            {

                SuccessOrExit(error = otCoapMessageSetPayloadMarker(message));

            }

            error = otCoapSendRequestBlockWiseWithParameters(GetInstancePtr(), message, &messageInfo,

                                                             &Coap::HandleResponse, this, GetRequestTxParameters(),

                                                             Coap::BlockwiseTransmitHook, Coap::BlockwiseReceiveHook);

        }

        else

        {

#endif

            error = otCoapSendRequestWithParameters(GetInstancePtr(), message, &messageInfo, &Coap::HandleResponse,

                                                    this, GetRequestTxParameters());

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        }

#endif

    }

    else

    {

        error = otCoapSendRequestWithParameters(GetInstancePtr(), message, &messageInfo, nullptr, nullptr,

                                                GetResponseTxParameters());

    }

exit:

    if ((error != OT_ERROR_NONE) && (message != nullptr))

    {

        otMessageFree(message);

    }

    return error;

}

otError Coap::Process(Arg aArgs[])

{

#define CmdEntry(aCommandString)                            \

    {                                                       \

        aCommandString, &Coap::Process<Cmd(aCommandString)> \

    }

    static constexpr Command kCommands[] = {

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        CmdEntry("cancel"),

#endif

        CmdEntry("delete"),

        CmdEntry("get"),

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        CmdEntry("observe"),

#endif

        CmdEntry("parameters"),

        CmdEntry("post"),

        CmdEntry("put"),

        CmdEntry("resource"),

        CmdEntry("set"),

        CmdEntry("start"),

        CmdEntry("stop"),

    };

#undef CmdEntry

    static_assert(BinarySearch::IsSorted(kCommands), "kCommands is not sorted");

    otError        error = OT_ERROR_INVALID_COMMAND;

    const Command *command;

    if (aArgs[0].IsEmpty() || (aArgs[0] == "help"))

    {

        OutputCommandTable(kCommands);

        ExitNow(error = aArgs[0].IsEmpty() ? OT_ERROR_INVALID_ARGS : OT_ERROR_NONE);

    }

    command = BinarySearch::Find(aArgs[0].GetCString(), kCommands);

    VerifyOrExit(command != nullptr);

    error = (this->*command->mHandler)(aArgs + 1);

exit:

    return error;

}

void Coap::HandleRequest(void *aContext, otMessage *aMessage, const otMessageInfo *aMessageInfo)

{

    static_cast<Coap *>(aContext)->HandleRequest(aMessage, aMessageInfo);

}

void Coap::HandleRequest(otMessage *aMessage, const otMessageInfo *aMessageInfo)

{

    otError    error           = OT_ERROR_NONE;

    otMessage *responseMessage = nullptr;

    otCoapCode responseCode    = OT_COAP_CODE_EMPTY;

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    uint64_t observe        = 0;

    bool     observePresent = false;

#endif

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

    uint64_t blockValue   = 0;

    bool     blockPresent = false;

#endif

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE || OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

    otCoapOptionIterator iterator;

#endif

    OutputFormat("coap request from ");

    OutputIp6Address(aMessageInfo->mPeerAddr);

    OutputFormat(" ");

    switch (otCoapMessageGetCode(aMessage))

    {

    case OT_COAP_CODE_GET:

        OutputFormat("GET");

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE || OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        SuccessOrExit(error = otCoapOptionIteratorInit(&iterator, aMessage));

#endif

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        if (otCoapOptionIteratorGetFirstOptionMatching(&iterator, OT_COAP_OPTION_OBSERVE) != nullptr)

        {

            SuccessOrExit(error = otCoapOptionIteratorGetOptionUintValue(&iterator, &observe));

            observePresent = true;

            OutputFormat(" OBS=");

            OutputUint64(observe);

        }

#endif

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        if (otCoapOptionIteratorGetFirstOptionMatching(&iterator, OT_COAP_OPTION_BLOCK2) != nullptr)

        {

            SuccessOrExit(error = otCoapOptionIteratorGetOptionUintValue(&iterator, &blockValue));

            blockPresent = true;

        }

#endif

        break;

    case OT_COAP_CODE_DELETE:

        OutputFormat("DELETE");

        break;

    case OT_COAP_CODE_PUT:

        OutputFormat("PUT");

        break;

    case OT_COAP_CODE_POST:

        OutputFormat("POST");

        break;

    default:

        OutputLine("Undefined");

        ExitNow(error = OT_ERROR_PARSE);

    }

    PrintPayload(aMessage);

    if (otCoapMessageGetType(aMessage) == OT_COAP_TYPE_CONFIRMABLE ||

        otCoapMessageGetCode(aMessage) == OT_COAP_CODE_GET)

    {

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        if (observePresent && (mSubscriberTokenLength > 0) && (observe == 0))

        {

            // There is already a subscriber

            responseCode = OT_COAP_CODE_SERVICE_UNAVAILABLE;

        }

        else

#endif

            if (otCoapMessageGetCode(aMessage) == OT_COAP_CODE_GET)

        {

            responseCode = OT_COAP_CODE_CONTENT;

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

            if (observePresent)

            {

                if (observe == 0)

                {

                    // New subscriber

                    OutputLine("Subscribing client");

                    mSubscriberSock.mAddress = aMessageInfo->mPeerAddr;

                    mSubscriberSock.mPort    = aMessageInfo->mPeerPort;

                    mSubscriberTokenLength   = otCoapMessageGetTokenLength(aMessage);

                    memcpy(mSubscriberToken, otCoapMessageGetToken(aMessage), mSubscriberTokenLength);

                    /*

                     * Implementer note.

                     *

                     * Here, we try to match a confirmable GET request with confirmable

                     * notifications, however this is not a requirement of RFC7641:

                     * the server can send notifications of either type regardless of

                     * what the client used to subscribe initially.

                     */

                    mSubscriberConfirmableNotifications = (otCoapMessageGetType(aMessage) == OT_COAP_TYPE_CONFIRMABLE);

                }

                else if (observe == 1)

                {

                    // See if it matches our subscriber token

                    if ((otCoapMessageGetTokenLength(aMessage) == mSubscriberTokenLength) &&

                        (memcmp(otCoapMessageGetToken(aMessage), mSubscriberToken, mSubscriberTokenLength) == 0))

                    {

                        // Unsubscribe request

                        CancelSubscriber();

                    }

                }

            }

#endif // OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

        }

        else

        {

            responseCode = OT_COAP_CODE_CHANGED;

        }

        responseMessage = otCoapNewMessage(GetInstancePtr(), nullptr);

        VerifyOrExit(responseMessage != nullptr, error = OT_ERROR_NO_BUFS);

        SuccessOrExit(

            error = otCoapMessageInitResponse(responseMessage, aMessage, OT_COAP_TYPE_ACKNOWLEDGMENT, responseCode));

        if (responseCode == OT_COAP_CODE_CONTENT)

        {

#if OPENTHREAD_CONFIG_COAP_OBSERVE_API_ENABLE

            if (observePresent && (observe == 0))

            {

                SuccessOrExit(error = otCoapMessageAppendObserveOption(responseMessage, mObserveSerial++));

            }

#endif

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

            if (blockPresent)

            {

                SuccessOrExit(error = otCoapMessageAppendBlock2Option(responseMessage,

                                                                      static_cast<uint32_t>(blockValue >> 4), true,

                                                                      static_cast<otCoapBlockSzx>(blockValue & 0x7)));

                SuccessOrExit(error = otCoapMessageSetPayloadMarker(responseMessage));

            }

            else

            {

#endif

                SuccessOrExit(error = otCoapMessageSetPayloadMarker(responseMessage));

                SuccessOrExit(error = otMessageAppend(responseMessage, mResourceContent,

                                                      static_cast<uint16_t>(strlen(mResourceContent))));

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

            }

#endif

        }

#if OPENTHREAD_CONFIG_COAP_BLOCKWISE_TRANSFER_ENABLE

        if (blockPresent)

        {

            SuccessOrExit(error = otCoapSendResponseBlockWiseWithParameters(GetInstancePtr(), responseMessage,

                                                                            aMessageInfo, GetResponseTxParameters(),

                                                                            this, mResource.mTransmitHook));

        }

        else