From d8786f39c6d2f3752c676efeb2f6e027ec326a0b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcin=20Zieli=C5=84ski?= <marcin.zielinski@mudita.com>
Date: Wed, 30 Nov 2022 14:26:51 +0100
Subject: [PATCH] [MOS-839] Fix crashes after a few VoLTE toggles

Those were occuring after calls which were preceded by
a few VoLTE on/off toggles.
---
 .../service-cellular/call/CellularCall.cpp    |  2 +-
 .../call/api/ModemCallApi.cpp                 | 58 ++++++++-----------
 .../call/api/ModemCallApi.hpp                 | 10 +++-
 3 files changed, 34 insertions(+), 36 deletions(-)

diff --git a/module-services/service-cellular/call/CellularCall.cpp b/module-services/service-cellular/call/CellularCall.cpp
index b827ba99b1b35519078a5722571243cd422d3b86..758c056cb354af776377b5f28ed4e61578ffee01 100644
--- a/module-services/service-cellular/call/CellularCall.cpp
+++ b/module-services/service-cellular/call/CellularCall.cpp
@@ -28,7 +28,7 @@ namespace call
                                                               std::make_unique<CallDB>(owner),
                                                               std::make_unique<CallTimer>(std::move(timer)),
                                                               std::make_unique<TimerRing>(std::move(timerRing)),
-                                                              std::make_unique<cellular::Api>(owner, cmux),
+                                                              std::make_unique<cellular::Api>(owner),
                                                               std::move(sentinel)});
     }
 
diff --git a/module-services/service-cellular/call/api/ModemCallApi.cpp b/module-services/service-cellular/call/api/ModemCallApi.cpp
index bfc02bf3cc9d7afa2c497dc6b671e623fe614723..eba48934ff4304a8d4f79e0911ef82dcc996a698 100644
--- a/module-services/service-cellular/call/api/ModemCallApi.cpp
+++ b/module-services/service-cellular/call/api/ModemCallApi.cpp
@@ -3,58 +3,50 @@
 
 #include "ModemCallApi.hpp"
 #include <modem/mux/CellularMux.h>
+#include <module-cellular/at/Commands.hpp>
 #include <stdexcept>
 #include <service-cellular/ServiceCellular.hpp>
 #include <service-db/agents/settings/SystemSettings.hpp>
 
 namespace cellular
 {
-    Api::Api(ServiceCellular *cellular, CellularMux *cmux) : cellular(cellular), cmux(cmux)
+    Api::Api(ServiceCellular *cellular) : cellular{cellular}
     {}
 
-    bool Api::answerIncomingCall()
+    bool Api::handleEvent(at::AT modemCommand)
     {
-        if (cmux == nullptr) {
-            throw std::runtime_error("call api not initialized");
+        if (!cellular->cmux) {
+            LOG_INFO("no cmux at this time - ignoring request");
+            return false;
+        }
+
+        auto channel = cellular->cmux->get(CellularMux::Channel::Commands);
+        if (!channel) {
+            LOG_INFO("no cmux command channel at this time - ignoring request");
+            return false;
         }
-        auto channel = cmux->get(CellularMux::Channel::Commands);
-        if (channel != nullptr) {
-            auto response = channel->cmd(at::AT::ATA);
-            if (response) {
-                return true;
-            }
+
+        if (!channel->cmd(modemCommand)) {
+            LOG_WARN("AT+%s command failed - ignoring request", magic_enum::enum_name(modemCommand).data());
+            return false;
         }
-        return false;
+
+        return true;
+    }
+
+    bool Api::answerIncomingCall()
+    {
+        return handleEvent(at::AT::ATA);
     }
 
     bool Api::hangupCall()
     {
-        if (cmux == nullptr) {
-            return false;
-        }
-        auto channel = cmux->get(CellularMux::Channel::Commands);
-        if (channel != nullptr) {
-            auto response = channel->cmd(at::AT::ATH);
-            if (response) {
-                return true;
-            }
-        }
-        return false;
+        return handleEvent(at::AT::ATH);
     }
 
     bool Api::rejectCall()
     {
-        if (cmux == nullptr) {
-            return false;
-        }
-        auto channel = cmux->get(CellularMux::Channel::Commands);
-        if (channel != nullptr) {
-            auto response = channel->cmd(at::AT::CHUP);
-            if (response) {
-                return true;
-            }
-        }
-        return false;
+        return handleEvent(at::AT::CHUP);
     }
 
     bool Api::areCallsFromFavouritesEnabled()
diff --git a/module-services/service-cellular/call/api/ModemCallApi.hpp b/module-services/service-cellular/call/api/ModemCallApi.hpp
index 185dc5ed768dcf5886ffadc6624e8bee395c4954..79d1de0627e9e92a6f1d07038ffa2ab227e831e5 100644
--- a/module-services/service-cellular/call/api/ModemCallApi.hpp
+++ b/module-services/service-cellular/call/api/ModemCallApi.hpp
@@ -6,6 +6,11 @@
 #include "PhoneModes/PhoneMode.hpp"
 #include "PhoneModes/Tethering.hpp"
 
+namespace at
+{
+    enum class AT;
+}
+
 class CellularMux;
 class ServiceCellular;
 
@@ -30,11 +35,12 @@ namespace cellular
     {
       private:
         ServiceCellular *cellular = nullptr;
-        CellularMux *cmux         = nullptr;
+
+        bool handleEvent(at::AT modemCommand);
 
       public:
         Api() = default;
-        Api(ServiceCellular *cellular, CellularMux *);
+        Api(ServiceCellular *cellular);
 
         bool answerIncomingCall() override;
         bool hangupCall() override;