From 3c4045e6206d8927c07fc0cae5c61ab35cbb0afd Mon Sep 17 00:00:00 2001
From: "Timur A. Fatkhullin" <timur@sao.ru>
Date: Tue, 10 Jun 2025 18:19:11 +0300
Subject: [PATCH] ...

---
 cxx/mcc_mount_events_states.h | 333 +++++++++++++++++++++++++++++++++-
 cxx/mount.h                   |  31 +++-
 2 files changed, 348 insertions(+), 16 deletions(-)

diff --git a/cxx/mcc_mount_events_states.h b/cxx/mcc_mount_events_states.h
index ddab3a6..60f7375 100644
--- a/cxx/mcc_mount_events_states.h
+++ b/cxx/mcc_mount_events_states.h
@@ -3,7 +3,8 @@
 /*  MOUNT CONTROL COMPONENTS LIBRARY  */
 
 /*
- *  BASIC EVENTS AND MOUNT STATES DEFINITIONS
+ *  BASIC EVENTS AND MOUNT STATES DEFINITIONS (REFERENCE IMPLEMENTATION)
+ *
  */
 
 
@@ -12,18 +13,332 @@
 namespace mcc
 {
 
-template <MccMountType MOUNT_TYPE,
-          std::derived_from<MccMountConfig> CONFIG_TYPE,
-          std::derived_from<MccMount<MOUNT_TYPE, CONFIG_TYPE>> MountT>
-struct MccMountInitEvent {
+namespace traits
+{
+
+template <typename T>
+concept mcc_mount_c = requires {
+    requires std::same_as<const MccMountType, decltype(T::mountType)>;
+
+    typename T::mount_config_t;
+
+    requires std::derived_from<T, MccMount<T::mountType, typename T::mount_config_t>>;
+};
+
+}  // namespace traits
+
+
+
+/*  MOUNT STATE MACHINE STATES  */
+
+
+// a base class for mount state machine events
+
+template <traits::mcc_mount_c MountT>
+class MccMountEventBase
+{
+protected:
+    typedef MountT mount_t;
+
+    MccMountEventBase(mount_t& mount) : _mount(mount) {}
+
+    virtual ~MccMountEventBase() = default;
+
+    mount_t& mount() const
+    {
+        return _mount;
+    }
+
+    mount_t& _mount;
+};
+
+
+// transit to IDLE state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventIDLE : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-IDLE-EVENT";
+
+    // CTAD does not work for clang++ (at least till v. 20 and -std=c++23)!
+    // so, one must explicitly define constructor here
+    MccMountEventIDLE(MountT& mount) : base_t(mount) {}
+};
+
+
+// transit to initialization state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventInit : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
     static constexpr std::string_view ID = "MCC-MOUNT-INIT-EVENT";
 
-    MccMountInitEvent(MountT& mount) : _mount(mount) {}
+    // CTAD does not work for clang++ (at least till v. 20 and -std=c++23)!
+    // so, one must explicitly define constructor here
+    MccMountEventInit(MountT& mount) : base_t(mount) {}
+};
 
-    MountT mount() const { return _mount; }
 
-private:
-    MountT& _mount;
+// transit to error state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventError : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-ERROR-EVENT";
+
+    using event_data_t = std::error_code;
+
+    event_data_t eventData() const
+    {
+        return _error;
+    }
+
+    MccMountEventError(MountT& mount, const event_data_t& error) : base_t(mount), _error(error) {}
+
+protected:
+    event_data_t _error;
+};
+
+
+// transit to slew state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventSlew : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-SLEW-EVENT";
+
+    struct event_data_t {
+        MccCoordPairKind kind{MccCoordPairKind::COORDS_KIND_RADEC_IRCS};
+        MccAngle x{0.0}, y{0.0};
+
+        bool stop{false};  // stop after slewing: if false - start guiding
+    };
+
+    event_data_t eventData() const
+    {
+        return _eventData;
+    }
+
+    MccMountEventSlew(MountT& mount, const event_data_t& ev_data) : base_t(mount), _eventData(ev_data) {}
+
+protected:
+    event_data_t _eventData;
+};
+
+
+// transit to guiding state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventGuiding : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-GUIDING-EVENT";
+
+    // CTAD does not work for clang++ (at least till v. 20 and -std=c++23)!
+    // so, one must explicitly define constructor here
+    MccMountEventGuiding(MountT& mount) : base_t(mount) {}
+};
+
+
+// transit to stop state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventStop : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-STOP-EVENT";
+
+    enum event_data_t {
+        EVENT_STOP_CLIENT,  // software stop (mount client)
+        EVENT_STOP_BUTTON   // hardware button
+    };
+
+    event_data_t eventData() const
+    {
+        return _reason;
+    }
+
+    MccMountEventStop(MountT& mount, event_data_t reason) : base_t(mount), _reason(reason) {}
+
+protected:
+    event_data_t _reason;
+};
+
+
+// transit to shutdown state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountEventShutdown : public MccMountEventBase<MountT> {
+    typedef MccMountEventBase<MountT> base_t;
+
+    static constexpr std::string_view ID = "MCC-MOUNT-SHUTDOWN-EVENT";
+
+    // CTAD does not work for clang++ (at least till v. 20 and -std=c++23)!
+    // so, one must explicitly define constructor here
+    MccMountEventShutdown(MountT& mount) : base_t(mount) {}
+};
+
+
+/*  MOUNT STATE MACHINE STATES  */
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateBase {
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void exit(this auto&& self, EvT& event)
+    {
+        using self_t = std::remove_cvref_t<decltype(self)>;
+
+        std::forward<decltype(self)>(self).exitImpl(event);
+
+        event.mount().logDebug("Exit from '{}' state due to '{}' event ...", self_t::ID, EvT::ID);
+    }
+
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void enter(this auto&& self, EvT& event)
+    {
+        using self_t = std::remove_cvref_t<decltype(self)>;
+
+        event.mount().logDebug("Enter to '{}' state due to '{}' event ...", self_t::ID, EvT::ID);
+
+        std::forward<decltype(self)>(self).enterImpl(event);
+    }
+
+protected:
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void exitImpl(EvT& event)
+    {
+        event.mount().logWarning("Call an empty MccMountStateBase::exitImpl method!!! Event type is '{}'", EvT::ID);
+    }
+
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void enterImpl(EvT& event)
+    {
+        event.mount().logWarning("Call an empty MccMountStateBase::enterImpl method!!! Event type is '{}'", EvT::ID);
+    }
+};
+
+
+
+// just forward declarations
+template <traits::mcc_mount_c MountT>
+struct MccMountStateIDLE;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateInit;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateError;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateSlew;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateStop;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateGuiding;
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateShutdown;
+
+
+// initialization state
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateInit : MccMountStateBase<MountT> {
+    static constexpr std::string_view ID = "MCC-MOUNT-INIT-STATE";
+
+    using transition_t = fsm::fsm_transition_table_t<std::pair<MccMountEventIDLE<MountT>, MccMountStateIDLE<MountT>>>;
+
+protected:
+    void exitImpl(MccMountEventIDLE<MountT>& event)
+    {
+        // normal exit from the state
+    }
+
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void enterImpl(EvT& event)
+    {
+        event.mount().initMount();
+
+        // switch to IDLE state
+        event.mount().template dispatchEvent<MccMountEventIDLE<MountT>>();
+    }
+};
+
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateError : MccMountStateBase<MountT> {
+    static constexpr std::string_view ID = "MCC-MOUNT-ERROR-STATE";
+
+    using transition_t = fsm::fsm_transition_table_t<
+        std::pair<MccMountEventIDLE<MountT>, MccMountStateIDLE<MountT>>,  // ???? after error correction?
+        std::pair<MccMountEventInit<MountT>, MccMountStateInit<MountT>>,
+        std::pair<MccMountEventError<MountT>, MccMountStateError<MountT>>,
+        std::pair<MccMountEventSlew<MountT>, MccMountStateError<MountT>>,
+        std::pair<MccMountEventGuiding<MountT>, MccMountStateError<MountT>>,
+        std::pair<MccMountEventStop<MountT>, MccMountStateError<MountT>>,
+        std::pair<MccMountEventShutdown<MountT>, MccMountStateShutdown<MountT>>>;
+
+protected:
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void exitImpl(EvT& event)
+    {
+        event.mount().logWarning(
+            "The mount is in the error state!!! One must correct it before transit to any states! Event type is '{}'",
+            EvT::ID);
+    }
+
+    void exitImpl(MccMountEventIDLE<MountT>& event)
+    {
+        event.mount().logWarning("Suppose the error was corrected!");
+    }
+
+    void exitImpl(MccMountEventInit<MountT>& event)
+    {
+        // normal exit from the state
+    }
+
+    template <std::derived_from<MccMountEventBase<MountT>> EvT>
+    void enterImpl(EvT& event)
+    {
+        auto err = event.eventData();
+
+        event.mount().logError("The mount is in the error state: code = {}, category = {}, message = '{}'", err.value(),
+                               err.category().name(), err.message());
+    }
+};
+
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateIDLE : MccMountStateBase<MountT> {
+    static constexpr std::string_view ID = "MCC-MOUNT-IDLE-STATE";
+
+    using transition_t =
+        fsm::fsm_transition_table_t<std::pair<MccMountEventInit<MountT>, MccMountStateInit<MountT>>,
+                                    std::pair<MccMountEventError<MountT>, MccMountStateError<MountT>>,
+                                    std::pair<MccMountEventSlew<MountT>, MccMountStateSlew<MountT>>,
+                                    std::pair<MccMountEventGuiding<MountT>, MccMountStateGuiding<MountT>>,
+                                    std::pair<MccMountEventStop<MountT>, MccMountStateIDLE<MountT>>,
+                                    std::pair<MccMountEventShutdown<MountT>, MccMountStateShutdown<MountT>>>;
+};
+
+
+template <traits::mcc_mount_c MountT>
+struct MccMountStateShutdown : MccMountStateBase<MountT> {
+    static constexpr std::string_view ID = "MCC-MOUNT-SHUTDOWN-STATE";
+
+    using transition_t =
+        fsm::fsm_transition_table_t<std::pair<MccMountEventInit<MountT>, MccMountStateInit<MountT>>,
+                                    std::pair<MccMountEventError<MountT>, MccMountStateError<MountT>>,
+                                    std::pair<MccMountEventSlew<MountT>, MccMountStateSlew<MountT>>,
+                                    std::pair<MccMountEventGuiding<MountT>, MccMountStateGuiding<MountT>>,
+                                    std::pair<MccMountEventStop<MountT>, MccMountStateIDLE<MountT>>,
+                                    std::pair<MccMountEventShutdown<MountT>, MccMountStateShutdown<MountT>>>;
 };
 
 }  // namespace mcc
diff --git a/cxx/mount.h b/cxx/mount.h
index 2f000aa..082eda4 100644
--- a/cxx/mount.h
+++ b/cxx/mount.h
@@ -222,7 +222,6 @@ public:
     };
 
 
-
     /*  Constructors and destructor  */
 
     template <fsm::traits::fsm_state_c InitStateT>
@@ -244,17 +243,26 @@ public:
         updateIERSDatabase(IERS_DB_EARTH_ORIENT);
     }
 
-    virtual ~MccMount() { logDebug("Delete MccMount class instance: thread = {}", getThreadId()); }
+    virtual ~MccMount()
+    {
+        logDebug("Delete MccMount class instance: thread = {}", getThreadId());
+    }
 
 
     /*  Public methods  */
 
-    MccMountPosition getMountData() const noexcept { return _currentMountOrient.load(); }
+    MccMountPosition getMountData() const noexcept
+    {
+        return _currentMountOrient.load();
+    }
 
 
     // geo location setters/getters
 
-    void setGeoLocation(const MccMountSiteInfo& geoloc) { _geoLocation.store(geoloc); }
+    void setGeoLocation(const MccMountSiteInfo& geoloc)
+    {
+        _geoLocation.store(geoloc);
+    }
 
     void setSiteLatitude(const MccAngle& lat)
     {
@@ -282,14 +290,23 @@ public:
     }
 
 
-    MccMountSiteInfo getGeoLocation() const { return _geoLocation.load(); }
+    MccMountSiteInfo getGeoLocation() const
+    {
+        return _geoLocation.load();
+    }
 
 
     // current meteo setters/getters
 
-    void setMeteo(const MccMountMeteo& meteo) { _currentMeteo.store(meteo); }
+    void setMeteo(const MccMountMeteo& meteo)
+    {
+        _currentMeteo.store(meteo);
+    }
 
-    MccMountMeteo getMeteo() const { return _currentMeteo.load(); }
+    MccMountMeteo getMeteo() const
+    {
+        return _currentMeteo.load();
+    }
 
 
     /* prohibited zone related methods */