#ifndef STAGINGBUFFER_H
#define STAGINGBUFFER_H

#include <memory>
#include <cstdint>
#include <functional>
#include <atomic>

namespace smo {
namespace stim_buff {

/**
 * StagingBuffer manages a large buffer to guide io_uring in assembling some
 * number of Livox Avia pcloud UDP dgrams into a single stim frame.
 *
 * The buffer operates in a cycle:
 * 1. io_uring assembles UDP dgrams into the buffer until it's full
 * 2. Buffer is handed off to the stimbuff layer to be appended to the stimbuff.
 * 3. When the stimbuff layer has appended the current assembled frame, the
 *		assembly buffer is reset and cycle repeats.
 */
class StagingBuffer
{
public:
	class InputEngineConstraints
	{
	public:
		InputEngineConstraints();
		~InputEngineConstraints();
	};

	class OutputEngineConstraints
	{
	public:
		OutputEngineConstraints();
		~OutputEngineConstraints();
	};

public:
	/**	EXPLANATION:
	 * We use the input and output engine constraints to determine the total
	 * amount of memory required internally to assemble a single frame with
	 * the given number of points per frame.
	 */
	explicit StagingBuffer(
		const InputEngineConstraints& inputEngineConstraints,
		const OutputEngineConstraints& outputEngineConstraints,
		size_t nPointsPerFrame);
	~StagingBuffer();

	// Non-copyable, movable
	StagingBuffer(const StagingBuffer&) = delete;
	StagingBuffer& operator=(const StagingBuffer&) = delete;
	StagingBuffer(StagingBuffer&&) = default;
	StagingBuffer& operator=(StagingBuffer&&) = default;

public:
	// operator IoUringQueueDescriptor() const;
	// operator OpenClSharedBufferDescriptor() const;

	bool isAssembling() const { return isAssembling_; }
	void startAssembly();
	void stopAssembly();

private:
	// Buffer data
	std::unique_ptr<uint8_t[]> buffer_;
	size_t bufferSize_;

	// Current state
	std::atomic<size_t> currentSize_;
	std::atomic<bool> isAssembling_;
};

class IoUringConstraints
:	public StagingBuffer::InputEngineConstraints
{
public:
	IoUringConstraints()
	:	StagingBuffer::InputEngineConstraints()
	{}
	~IoUringConstraints() = default;
};

class OpenClConstraints
:	public StagingBuffer::OutputEngineConstraints
{
public:
	OpenClConstraints()
	:	StagingBuffer::OutputEngineConstraints()
	{}
	~OpenClConstraints() = default;
};

} // namespace stim_buff
} // namespace smo

#endif // STAGINGBUFFER_H