integration/Source/Integration/LockedWrapper.h

#pragma once

#include "CoreMinimal.h"
#include "lpx-enginewrapper.hpp"
#include "CommonTypes.h"

// Class FLockableWrapper
// 
// Contains the EngineWrapper and a Mutex to lock it.
// This class has no methods.  To access the EngineWrapper,
// construct a FLockedWrapper, and then dereference it
// using operator right arrow.
//
class FLockableWrapper {
private:
	FCriticalSection Mutex;
	EngineWrapper Wrapper;

	// Temporary buffers. These are only used
	// inside wrapper methods.  There's nothing
	// persistent in these.
	//
	TArray<uint32> AQLenBuffer;
	TArray<const char*> AQStrBuffer;
	
public:
	friend class FLockedWrapper;
};

class FLockedWrapper {
private:
	FLockableWrapper& Lockable;

public:
		// Import these types into our Namespace.
		using IdArray       = CommonTypes::IdArray;
		using IdView        = CommonTypes::IdView;
		using StringViewVec = CommonTypes::StringViewVec;

public:
	// The constructor of the FLockedWrapper claims the mutex.
	FLockedWrapper(FLockableWrapper& w) : Lockable(w) {
		Lockable.Mutex.Lock();
	}

	// The destructor of the FLockedWrapper releases the mutex.
	~FLockedWrapper() {
		Lockable.Mutex.Unlock();
	}

	// Operator right arrow accesses the EngineWrapper.
	EngineWrapper* operator ->() {
		return &Lockable.Wrapper;
	}

	// Get a pointer to the enginewrapper.  This is not
	// very safe because you could keep the pointer after
	// the LockedWrapper is destroyed.  Don't do that.
	EngineWrapper* Get() {
		return &Lockable.Wrapper;
	}

	// Initialize the engine wrapper if it's not already.
	//
	// All this does is open the DLL and hook up all
	// the function pointers in the wrapper to point into
	// the DLL.
	//
	void InitWrapper();

	// Fetch Stdout as a string.
	//
	FString FetchStdout();

	// Get the current Actor ID.
	//
	int64 GetActor();

	// Get the list of tangibles near the actor.
	//
	// This function is fast but not free.  You should fetch this
	// once per frame and then store the IdView somewhere (like
	// in the TangibleManager, for example).
	//
	IdView GetNear(int64 id, double rx, double ry, double rz);

	// Get animation queues.
	//
	// The array returned by this is valid until the
	// next time you call this.
	//
	StringViewVec GetAnimationQueues(IdView ids);
};