// This code implements the functionality of my older msxtar program

// that could manipulate files and directories on dsk and ide-hd images

// Integrating it is seen as temporary bypassing of the need for a

// DirAsDisk2 that supports subdirs, partitions etc. since this class will

// of those functionalities although not on a dynamic base

#ifndef MSXTAR_HH

#define MSXTAR_HH

#include "DiskImageUtils.hh"

#include "TclObject.hh"

#include "MemBuffer.hh"

#include "zstring_view.hh"

#include <cstdint>

#include <string_view>

#include <variant>

namespace openmsx {

class SectorAccessibleDisk;

class MsxChar2Unicode;

namespace FAT {

	struct Free {

		[[nodiscard]] auto operator<=>(const Free&) const = default;

	};

	struct EndOfChain {

		[[nodiscard]] auto operator<=>(const EndOfChain&) const = default;

	};

	struct Cluster {

		unsigned index;

		[[nodiscard]] auto operator<=>(const Cluster&) const = default;

	};

	using DirCluster = std::variant<Free, Cluster>;

	using FatCluster = std::variant<Free, EndOfChain, Cluster>;

	using FileName = decltype(MSXDirEntry::filename);

}

class MSXtar

{

public:

	enum class Add : uint8_t {

		PRESERVE,

		OVERWRITE,

	};

public:

	explicit MSXtar(SectorAccessibleDisk& disk, const MsxChar2Unicode& msxChars_);

	MSXtar(MSXtar&& other) noexcept;

	~MSXtar();

	void chdir(std::string_view newRootDir);

	void mkdir(std::string_view newRootDir);

	std::string dir(); // formatted output

	TclObject dirRaw(); // unformatted output

	std::string addItem(const std::string& hostItemName, Add add); // add file or directory

	std::string addFile(const std::string& filename, Add add);

	std::string addDir(std::string_view rootDirName, Add add); // add files from host-dir, but does not create a top-level dir on the msx side

	std::string getItemFromDir(std::string_view rootDirName, std::string_view itemName);

	void getDir(std::string_view rootDirName);

	std::string deleteItem(std::string_view itemName); // delete file or directory (recursive)

	std::string renameItem(std::string_view currentName, std::string_view newName); // rename file or directory

	[[nodiscard]] std::string convertToMsxName(std::string_view name) const; // truncate to 8.3 filename

	struct FreeSpaceResult {

		unsigned numFreeClusters;

		unsigned clusterSize; // in bytes

	};

	[[nodiscard]] FreeSpaceResult getFreeSpace() const;

private:

	struct DirEntry {

		unsigned sector;

		unsigned index;

	};

	void writeLogicalSector(unsigned sector, const SectorBuffer& buf);

	void readLogicalSector (unsigned sector,       SectorBuffer& buf);

	[[nodiscard]] unsigned clusterToSector(FAT::Cluster cluster) const;

	[[nodiscard]] FAT::Cluster sectorToCluster(unsigned sector) const;

	void parseBootSector(const MSXBootSector& boot);

	[[nodiscard]] FAT::FatCluster readFAT(FAT::Cluster cluster) const;

	void writeFAT(FAT::Cluster cluster, FAT::FatCluster value);

	[[nodiscard]] FAT::Cluster findFirstFreeCluster();

	[[nodiscard]] unsigned countFreeClusters() const;

	[[nodiscard]] unsigned findUsableIndexInSector(unsigned sector);

	[[nodiscard]] unsigned getNextSector(unsigned sector) const;

	[[nodiscard]] unsigned appendClusterToSubdir(unsigned sector);

	[[nodiscard]] DirEntry addEntryToDir(unsigned sector);

	[[nodiscard]] unsigned addSubdir(const FAT::FileName& msxName,

	                                 uint16_t t, uint16_t d, unsigned sector);

	void alterFileInDSK(MSXDirEntry& msxDirEntry, const std::string& hostName);

	void deleteItem(std::string_view itemName, unsigned sector);

	std::string deleteEntry(const FAT::FileName& msxName, unsigned rootSector);

	void deleteEntry(MSXDirEntry& msxDirEntry);

	void deleteDirectory(unsigned sector);

	void freeFatChain(FAT::FatCluster cluster);

	[[nodiscard]] unsigned addSubdirToDSK(zstring_view hostName,

	                                      const FAT::FileName& msxName, unsigned sector);

	[[nodiscard]] DirEntry findEntryInDir(const FAT::FileName& msxName, unsigned sector,

	                                      SectorBuffer& sectorBuf);

	std::string addFileToDSK(const std::string& fullHostName, unsigned sector, Add add);

	std::string addOrCreateSubdir(zstring_view hostDirName, unsigned sector, Add add);

	std::string recurseDirFill(std::string_view dirName, unsigned sector, Add add);

	void fileExtract(const std::string& resultFile, const MSXDirEntry& dirEntry);

	void recurseDirExtract(std::string_view dirName, unsigned sector);

	std::string singleItemExtract(std::string_view dirName, std::string_view itemName,

	                              unsigned sector);

	void chroot(std::string_view newRootDir, bool createDir);

private:

	[[nodiscard]] FAT::DirCluster getStartCluster(const MSXDirEntry& entry) const;

	void setStartCluster(MSXDirEntry& entry, FAT::DirCluster cluster) const;

	[[nodiscard]] FAT::FileName hostToMSXFileName(std::string_view hostName) const;

	[[nodiscard]] std::string msxToHostFileName(const FAT::FileName& msxName) const;

	SectorAccessibleDisk& disk;

	MemBuffer<SectorBuffer> fatBuffer;

	const MsxChar2Unicode& msxChars;

	FAT::Cluster findFirstFreeClusterStart{0}; // all clusters before this one are in use

	unsigned clusterCount;

	unsigned fatCount;

	unsigned sectorsPerCluster;

	unsigned sectorsPerFat;

	unsigned fatStart;     // first sector of the first FAT

	unsigned rootDirStart; // first sector of the root directory

	unsigned dataStart;    // first sector of the cluster data

	unsigned chrootSector;

	bool fat16;

	bool fatCacheDirty;

};

} // namespace openmsx

#endif