#pragma once


#include <wfr/common/types/WfsTypes.h>
#include <wfr/common/types/LwdTypes.h>
#include <wfr/common/exceptions/exceptions.h>
#include <atomic>
#include <vector>
#include <memory>

namespace wfr {

// Forward declarations
namespace scheduling { class SchedulingDecision; }
namespace enactment { class WepBuilder; }

namespace wfs {

// Forward declarations
class Activity;


class ActivityInstance {
friend class enactment::WepBuilder;

// Static non-public properties
private:
	/**
	 * Static variable holding the next free activity instanceID.
	 **/
	static std::atomic<wfr_id_t> nextInstanceID;

	/**
	 * Returns the next free activity instanceID.
	 *
	 * @return next free activity instanceID.
	 */
	static wfr_id_t getNextInstanceID();

// Mutable properties that need to be accessed via getter-/setter-functions.
protected:
	/** Activity instance state. **/
	ActivityInstanceStatus status;

	/** Reference to the parent of this activity instance object (structure-wise). **/
	ActivityInstance* parentActivity = nullptr;

	/** Vector of successors. **/
	std::vector<ActivityInstance*> successors;

	/** Vector of predecessors. **/
	std::vector<ActivityInstance*> predecessors;

	/**  Reference to input data struct. **/
	lwd::_wfr_lwd *inputData = nullptr;
	bool inputDataOwnership = false;

	/**  Reference to output data struct. **/
	lwd::_wfr_lwd *outputData = nullptr;
	bool outputDataOwnership = false;

	bool allInputsAvailable = false;

	bool allOutputsAvailable = false;

	std::exception_ptr errorCause;

	wfr::wfr_timestamp_sc_t readyTime;

	wfr::wfr_timestamp_sc_t startTime;

	wfr::wfr_timestamp_sc_t endTime;

	uint64_t visitationCount = 0;

	bool dirtyStateFlag = false;

	std::shared_ptr<void> userData;

	std::shared_ptr<scheduling::SchedulingDecision> schedulingDecision;

// Invariant properties that can be accessed directly.
public:
	/** Unique ID of this activity instance object. **/
	const wfr_id_t instanceID;

	/** Activity this object is an instance of. **/
	const Activity& baseActivity;

	const wfr_id_t iterationID;

// Public functions
public:
	/**
	 * Constructor.
	 *
	 * @param parentActivity activity this object is an instance of.
	 */
	ActivityInstance(Activity& baseActivity, const wfr_id_t& iterationID = 0) noexcept;

	/** Destructor. **/
	virtual ~ActivityInstance() noexcept {
		if (inputData && inputDataOwnership) {
			delete inputData;
			inputData = nullptr;
		}
		if (outputData && outputDataOwnership) {
			delete outputData;
			outputData = nullptr;
		}
	}

	ActivityType activityType() const noexcept;

	bool isCompositeActivity() const noexcept;

	bool isLoop() const noexcept;

	bool isConditional() const noexcept;

	/**
	 * Returns the state of this activity instance.
	 *
	 * @return state of this activity instance.
	 **/
	ActivityInstanceStatus getInstanceStatus() const noexcept { return status; }

	/**
	 * Sets the state of this activity instance.
	 *
	 * @param status new state.
	 **/
	void setInstanceStatus(const ActivityInstanceStatus& status);

	/**
	 *
	 * Returns a reference to this activity instance input data.
	 *
	 * @return input data.
	 **/
	lwd::_wfr_lwd* const getInputData() const noexcept { return inputData; }

	/**
	 * Sets this instants input data.
	 *
	 * @param data input data.
	 */
	void setInputData(lwd::_wfr_lwd* data, bool ownership = true) noexcept {
		inputData = data;
		inputDataOwnership = ownership;
	}

	/**
	 *
	 * Returns a reference to this activity instance output data.
	 *
	 * @return output data.
	 **/
	lwd::_wfr_lwd* const getOutputData() const noexcept { return outputData; }

	/**
	 * Sets this instants output data.
	 *
	 * @param data output data.
	 */
	void setOutputData(lwd::_wfr_lwd* data, bool ownership = true) noexcept {
		outputData = data;
		outputDataOwnership = ownership;
	}

	/**
	 * Returns the number of predecessors.
	 *
	 * @return number of predecessors.
	 **/
	wfr_size_t getPredecessorCount() const noexcept { return predecessors.size(); }

	const std::vector<ActivityInstance*>& getPredecessors() const noexcept { return predecessors; }

	std::vector<ActivityInstance*>& getPredecessors() noexcept { return predecessors; }

	ActivityInstance* const getPredecessor(wfr_size_t index) const noexcept {
		return predecessors.at(index);
	}

	/**
	 * Returns the number of successors.
	 *
	 * @return number of successors.
	 **/
	wfr_size_t getSuccessorCount() const noexcept { return successors.size(); }

	const std::vector<ActivityInstance*>& getSuccessors() const noexcept { return successors; }

	std::vector<ActivityInstance*>& getSuccessors() noexcept { return successors; }

	ActivityInstance* const getSuccessor(int index) const noexcept {
		return successors.at(index);
	}

	/**
	 * Returns the parent of this instance (structure-wise).
	 *
	 * @return parent of this instance.
	 **/
	ActivityInstance* const getParentActivity() const noexcept { return parentActivity; }

	/**
	 * Sets the parent of this instance (structure-wise).
	 *
	 * parent parent of this instance.
	 **/
	void setParentActivity(ActivityInstance* parent) noexcept { this->parentActivity = parent; }


	bool areAllInputsAvailable() const noexcept { return allInputsAvailable; }

	void setAllInputsAvailable(const bool& areAvailable = true) noexcept {
		allInputsAvailable = areAvailable;
		dirtyStateFlag = false;
	}

	bool areAllOutputsAvailable() const noexcept { return allOutputsAvailable; }

	void setAllOutputsAvailable(const bool& areAvailable = true) noexcept { allOutputsAvailable = areAvailable; }


	std::exception_ptr getErrorCause() const noexcept { return errorCause; }

	void setErrorState(std::exception_ptr exception = nullptr)noexcept;


	const wfr::wfr_timestamp_sc_t& getReadyTime() const noexcept { return readyTime; }

	const wfr::wfr_timestamp_sc_t& getStartTime() const noexcept { return startTime; }

	const wfr::wfr_timestamp_sc_t& getEndTime() const noexcept { return endTime; }


	uint64_t getVisitationCount() const noexcept { return visitationCount; }

	void addToVisitationCount(uint64_t val = 1) noexcept { visitationCount += val; }


	void setDirtyState() { dirtyStateFlag = true; }

	bool isDirtyState() const { return dirtyStateFlag; }

	void resetDirtyState() { dirtyStateFlag = false; }


	virtual bool executePreExecutionHooks(bool earlyEvaluation) { return false; }

	virtual bool executeExecutionHook(bool earlyEvaluation) { return false; }

	virtual bool executePostExecutionHooks(bool earlyEvaluation) { return false; }

	std::shared_ptr<void> getUserData() { return userData; }

	void setUserData(std::shared_ptr<void> data) { userData = data; }

	void setSchedulingDecision(std::shared_ptr<scheduling::SchedulingDecision> sd = std::shared_ptr<scheduling::SchedulingDecision>()) noexcept {
		if (sd) {
			this->schedulingDecision = sd;
		} else {
			this->schedulingDecision.reset();
		}
	}

	virtual void executeSimMode() noexcept;



	template<class T>
	T& as() noexcept { return *static_cast<T*>(this); }

	template<class T>
	const T& as() const noexcept { return *static_cast<const T*>(this); }

};

} /* namespace wfs */
} /* namespace wfr */