#pragma once

#include "tl/ptr.h"

#include "fs/IMapSource.h"
#include "fs/AbsPath.h"
#include "fs/Api.h"

namespace fs
{

class NativeFilesystem;

class FS_API FileMapSource final : public IMapSource
{
	friend class NativeFilesystem;
public:
	explicit FileMapSource(AbsPathView filepath);
	FileMapSource(AbsPathView filepath, uint64_t start, size_t size);

	~FileMapSource() override;

	bool isValid() const;
	tl::optional<Error> getLastError() const override;

	size_t read(tl::span<uint8_t> data) override;

	void seekBeg(uint64_t offset) override;
	void seekRel(int64_t offset) override;

	uint64_t tell() const override;
	uint64_t getSize() const override;

	tl::span<const uint8_t> map(size_t size) override;

	bool isEOS() const override;

	size_t getPreferredBufferSize() const override;

private:
	uint64_t m_offset = 0;
	mutable tl::optional<Error> m_optLastError;

	struct Impl;
	tl::unique_ptr<Impl> m_impl;
};

}