// Copyright 2024 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CAMERA_HARDWARE_BUFFER_MINIGBM_ALLOCATOR_H_
#define CAMERA_HARDWARE_BUFFER_MINIGBM_ALLOCATOR_H_

#include <array>
#include <gbm.h>
#include <memory>

#include "allocator.h"

namespace crosLibcamera {

// The Minigbm Buffer allocator. The buffers are allocated from the graphics
// drivers through libminigbm.
class MinigbmAllocator : public Allocator
{
public:
	class BufferObject : public Allocator::BufferObject
	{
	public:
		BufferObject(struct gbm_bo *bo, uint32_t gbm_flags);
		BufferObject(const BufferObject &bo) = delete;
		BufferObject &operator=(const BufferObject &bo) = delete;
		BufferObject(BufferObject &&bo);
		BufferObject &operator=(BufferObject &&bo);
		~BufferObject() override;

		// Allocator::BufferObject implementation.
		BufferDescriptor Describe() const override;
		bool BeginCpuAccess(SyncType sync_type, int plane) override;
		bool EndCpuAccess(SyncType sync_type, int plane) override;
		bool Map(int plane) override;
		void Unmap(int plane) override;
		int GetPlaneFd(int plane) const override;
		void *GetPlaneAddr(int plane) const override;
		uint64_t GetId() const override;

	private:
		bool MapInternal(SyncType sync_type, int plane);
		void UnmapInternal(int plane);
		bool IsMapped(int plane) const;
		void Invalidate();

		static constexpr int kMaxPlanes = 4;

		struct PlaneData {
			// The per-plane map data returned by gbm_bo_map().
			void *map_data = nullptr;
			// The mapped virtual address.
			void *addr = nullptr;
		};

		// The gbm_bo associated with the buffer.
		struct gbm_bo *bo_ = nullptr;
		std::array<PlaneData, kMaxPlanes> plane_data_;

		BufferDescriptor desc_;
	};

	explicit MinigbmAllocator(struct gbm_device *gbm_device);
	~MinigbmAllocator() override;

	// Allocator implementation.
	std::unique_ptr<Allocator::BufferObject> CreateBo(
		int width, int height, uint32_t drm_format, uint32_t gbm_flags) override;
	std::unique_ptr<Allocator::BufferObject> ImportBo(
		const ImportData &data) override;
	bool IsFormatSupported(uint32_t drm_format, uint32_t gbm_flags) override;

private:
	struct gbm_device *gbm_device_ = nullptr;
};

std::unique_ptr<Allocator> CreateMinigbmAllocator();

} // namespace crosLibcamera

#endif // CAMERA_HARDWARE_BUFFER_MINIGBM_ALLOCATOR_H_