[api] enable DIAG_GET reset command into commissioner

the DIAG_GET reset command is used to notify the peer device to clear
the value of the diagnostic TLV such as `MAC counters TLV` which
contains several stats of network transmission.

include/commissioner/commissioner.hpp

@@ -1145,6 +1145,33 @@ class Commissioner
      *         The GIT_REVISION is included only when the commissioner is built in a
      *         git repository.
      */
+
+    /**
+     * @brief Asynchronously reset a set of available diagnostic TLV(s) value.
+     *
+     * This method notifies a Thread device to reset a set of diagnostic value by sending DIAG_GET.rst message.
+     * It always returns immediately without waiting for the completion. //TBC by real test
+     *
+     * @param[in, out] aHandler       A handler of all response and errors; Guaranteed to be called.
+     * @param[in]      aRloc          The RLOC of dest Thread device.
+     * @param[in]      aDiagTlvFlags  Diagnostic TLVs flags indicate which TLVs are wanted.
+     */
+
+    virtual void CommandDiagRest(ErrorHandler aHandler, uint16_t aRloc, uint64_t aaDiagTlvFlags) = 0;
+
+    /**
+     * @brief Synchronously reset a set of available diagnostic TLV(s) value.
+     *
+     * This method notifies a Thread device to reset a set of diagnostic value by sending DIAG_GET.rst message.
+     * It will not return until errors happened, timeouted or succeed.
+     * @param[out] aRawTlvData    A diagnostic TLVs data returned by the leader or other Thread Device.
+     * @param[in]  aRloc          The RLOC of dest Thread device.
+     * @param[in]  aDiagTlvFlags  Diagnostic TLVs flags indicate which TLVs are wanted.
+     *
+     */
+
+    virtual Error CommandDiagRest(uint16_t aRloc, uint64_t aDiagTlvFlags) = 0;
+
     static std::string GetVersion(void);
 };
 

src/library/commissioner_impl.cpp

@@ -653,6 +653,41 @@ void CommissionerImpl::SetPendingDataset(ErrorHandler aHandler, const PendingOpe
     }
 }
 
+void CommissionerImpl::CommandDiagReset(ErrorHandler aHandler, uint16_t aRloc, uint64_t aDiagTlvFlags)
+{
+    Error         error;
+    coap::Request request{coap::Type::kConfirmable, coap::Code::kPost};
+    auto          onResponse = [aHandler](const coap::Response *aResponse, Error aError) {
+        aHandler(HandleStateResponse(aResponse, aError));
+    };
+
+    VerifyOrExit(IsActive(), error = ERROR_INVALID_STATE("commissioner is not active"));
+    SuccessOrExit(error = request.SetUriPath(uri::kDiagRst));
+    SuccessOrExit(error = AppendTlv(request, {tlv::Type::kNetworkDiagTypeList, GetDiagTypeListTlvs(aDiagTlvFlags),
+                                              tlv::Scope::kNetworkDiag}));
+
+#if OT_COMM_CONFIG_CCM_ENABLE
+    if (IsCcmMode())
+    {
+        SuccessOrExit(error = SignRequest(request));
+    }
+#endif
+    if (aRloc == 0)
+    {
+        aRloc = kLeaderAloc16;
+    }
+
+    LOG_DEBUG(LOG_REGION_DIAG, "sending DIAG_GET.rst");
+    mProxyClient.SendRequest(request, onResponse, aRloc, kDefaultMmPort);
+    LOG_DEBUG(LOG_REGION_DIAG, "sent DIAG_GET.rst");
+
+exit:
+    if (error != ErrorCode::kNone)
+    {
+        aHandler(error);
+    }
+}
+
 #if OT_COMM_CONFIG_CCM_ENABLE
 void CommissionerImpl::SetBbrDataset(ErrorHandler aHandler, const BbrDataset &aDataset)
 {

src/library/commissioner_impl.hpp

@@ -196,6 +196,9 @@ class CommissionerImpl : public Commissioner
 
     struct event_base *GetEventBase() { return mEventBase; }
 
+    void  CommandDiagReset(ErrorHandler aHandler, uint16_t aRloc, uint64_t aaDiagTlvFlags) override;
+    Error CommandDiagReset(uint16_t, uint64_t) override { return ERROR_UNIMPLEMENTED(""); }
+
 private:
     using AsyncRequest = std::function<void()>;
 

src/library/commissioner_safe.cpp

@@ -561,6 +561,26 @@ void CommissionerSafe::Invoke(evutil_socket_t, short, void *aContext)
     }
 }
 
+void CommissionerSafe::CommandDiagReset(ErrorHandler aHandler, uint16_t aRloc, uint64_t aDiagTlvFlags)
+{
+    PushAsyncRequest([=]() { mImpl->CommandDiagReset(aHandler, aRloc, aDiagTlvFlags); });
+}
+
+Error CommissionerSafe::CommandDiagReset(uint16_t aRloc, uint64_t aDiagTlvFlags)
+{
+    std::promise<Error> pro;
+    auto                wait = [&pro](Error error) { pro.set_value(error); };
+
+    CommandDiagReset(wait, aRloc, aDiagTlvFlags);
+    std::future<Error> fut = pro.get_future();
+
+    if (fut.wait_for(std::chrono::seconds(10)) == std::future_status::timeout)
+    {
+        return ERROR_TIMEOUT("request to 10 timeout");
+    }
+    return fut.get();
+}
+
 void CommissionerSafe::PushAsyncRequest(AsyncRequest &&aAsyncRequest)
 {
     std::lock_guard<std::mutex> _(mInvokeMutex);

src/library/commissioner_safe.hpp

@@ -183,6 +183,9 @@ class CommissionerSafe : public Commissioner
 
     Error SetToken(const ByteArray &aSignedToken) override;
 
+    void  CommandDiagReset(ErrorHandler aHandler, uint16_t aRloc, uint64_t aaDiagTlvFlags) override;
+    Error CommandDiagReset(uint16_t aRloc, uint64_t aDiagTlvFlags) override;
+
 private:
     using AsyncRequest = std::function<void()>;