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#ifndef StatefulService_h
#define StatefulService_h
#include <Arduino.h>
#include <ArduinoJson.h>
#include <list>
#include <functional>
#ifdef ESP32
#include <freertos/FreeRTOS.h>
#include <freertos/semphr.h>
#endif
#ifndef DEFAULT_BUFFER_SIZE
#define DEFAULT_BUFFER_SIZE 1024
#endif
enum class StateUpdateResult { CHANGED = 0, // The update changed the state and propagation should take place if required
UNCHANGED, // The state was unchanged, propagation should not take place
ERROR // There was a problem updating the state, propagation should not take place
};
template <typename T> using JsonStateUpdater = std::function<StateUpdateResult(JsonObject& root, T& settings)>;
template <typename T> using JsonStateReader = std::function<void(T& settings, JsonObject& root)>;
typedef size_t update_handler_id_t; typedef std::function<void(const String& originId)> StateUpdateCallback;
typedef struct StateUpdateHandlerInfo { static update_handler_id_t currentUpdatedHandlerId; update_handler_id_t _id; StateUpdateCallback _cb; bool _allowRemove; StateUpdateHandlerInfo(StateUpdateCallback cb, bool allowRemove) : _id(++currentUpdatedHandlerId), _cb(cb), _allowRemove(allowRemove){}; } StateUpdateHandlerInfo_t;
template <class T> class StatefulService { public: template <typename... Args> #ifdef ESP32
StatefulService(Args&&... args) : _state(std::forward<Args>(args)...), _accessMutex(xSemaphoreCreateRecursiveMutex()) { } #else
StatefulService(Args&&... args) : _state(std::forward<Args>(args)...) { } #endif
update_handler_id_t addUpdateHandler(StateUpdateCallback cb, bool allowRemove = true) { if (!cb) { return 0; } StateUpdateHandlerInfo_t updateHandler(cb, allowRemove); _updateHandlers.push_back(updateHandler); return updateHandler._id; }
void removeUpdateHandler(update_handler_id_t id) { for (auto i = _updateHandlers.begin(); i != _updateHandlers.end();) { if ((*i)._allowRemove && (*i)._id == id) { i = _updateHandlers.erase(i); } else { ++i; } } }
StateUpdateResult update(std::function<StateUpdateResult(T&)> stateUpdater, const String& originId) { beginTransaction(); StateUpdateResult result = stateUpdater(_state); endTransaction(); if (result == StateUpdateResult::CHANGED) { callUpdateHandlers(originId); } return result; }
StateUpdateResult updateWithoutPropagation(std::function<StateUpdateResult(T&)> stateUpdater) { beginTransaction(); StateUpdateResult result = stateUpdater(_state); endTransaction(); return result; }
StateUpdateResult update(JsonObject& jsonObject, JsonStateUpdater<T> stateUpdater, const String& originId) { beginTransaction(); StateUpdateResult result = stateUpdater(jsonObject, _state); endTransaction(); if (result == StateUpdateResult::CHANGED) { callUpdateHandlers(originId); } return result; }
StateUpdateResult updateWithoutPropagation(JsonObject& jsonObject, JsonStateUpdater<T> stateUpdater) { beginTransaction(); StateUpdateResult result = stateUpdater(jsonObject, _state); endTransaction(); return result; }
void read(std::function<void(T&)> stateReader) { beginTransaction(); stateReader(_state); endTransaction(); }
void read(JsonObject& jsonObject, JsonStateReader<T> stateReader) { beginTransaction(); stateReader(_state, jsonObject); endTransaction(); }
void callUpdateHandlers(const String& originId) { for (const StateUpdateHandlerInfo_t& updateHandler : _updateHandlers) { updateHandler._cb(originId); } }
protected: T _state;
inline void beginTransaction() { #ifdef ESP32
xSemaphoreTakeRecursive(_accessMutex, portMAX_DELAY); #endif
}
inline void endTransaction() { #ifdef ESP32
xSemaphoreGiveRecursive(_accessMutex); #endif
}
private: #ifdef ESP32
SemaphoreHandle_t _accessMutex; #endif
std::list<StateUpdateHandlerInfo_t> _updateHandlers; };
#endif // end StatefulService_h
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