/******************************************************************************

 *

 * Project:  VSI Virtual File System

 * Purpose:  Declarations for classes related to the virtual filesystem.

 *           These would only be normally required by applications implementing

 *           their own virtual file system classes which should be rare.

 *           The class interface may be fragile through versions.

 * Author:   Frank Warmerdam, warmerdam@pobox.com

 *

 ******************************************************************************

 * Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>

 * Copyright (c) 2010-2014, Even Rouault <even dot rouault at spatialys.com>

 *

 * SPDX-License-Identifier: MIT

 ****************************************************************************/

#ifndef CPL_VSI_VIRTUAL_H_INCLUDED

#define CPL_VSI_VIRTUAL_H_INCLUDED

#include "cpl_progress.h"

#include "cpl_vsi.h"

#include "cpl_vsi_error.h"

#include "cpl_string.h"

#include <cstdint>

#include <map>

#include <memory>

#include <mutex>

#include <vector>

#include <string>

// To avoid aliasing to GetDiskFreeSpace to GetDiskFreeSpaceA on Windows

#ifdef GetDiskFreeSpace

#undef GetDiskFreeSpace

#endif

// To avoid aliasing to CopyFile to CopyFileA on Windows

#ifdef CopyFile

#undef CopyFile

#endif

/************************************************************************/

/*                           VSIVirtualHandle                           */

/************************************************************************/

/** Virtual file handle */

struct CPL_DLL VSIVirtualHandle

{

  public:

    virtual int Seek(vsi_l_offset nOffset, int nWhence) = 0;

    virtual vsi_l_offset Tell() = 0;

    virtual size_t Read(void *pBuffer, size_t nSize, size_t nCount) = 0;

    virtual int ReadMultiRange(int nRanges, void **ppData,

                               const vsi_l_offset *panOffsets,

                               const size_t *panSizes);

    /** This method is called when code plans to access soon one or several

     * ranges in a file. Some file systems may be able to use this hint to

     * for example asynchronously start such requests.

     *

     * Offsets may be given in a non-increasing order, and may potentially

     * overlap.

     *

     * @param nRanges Size of the panOffsets and panSizes arrays.

     * @param panOffsets Array containing the start offset of each range.

     * @param panSizes Array containing the size (in bytes) of each range.

     * @since GDAL 3.7

     */

    virtual void AdviseRead(CPL_UNUSED int nRanges,

                            CPL_UNUSED const vsi_l_offset *panOffsets,

                            CPL_UNUSED const size_t *panSizes)

    {

    }

    /** Return the total maximum number of bytes that AdviseRead() can handle

     * at once.

     *

     * Some AdviseRead() implementations may give up if the sum of the values

     * in the panSizes[] array provided to AdviseRead() exceeds a limit.

     *

     * Callers might use that threshold to optimize the efficiency of

     * AdviseRead().

     *

     * A returned value of 0 indicates a unknown limit.

     * @since GDAL 3.9

     */

    virtual size_t GetAdviseReadTotalBytesLimit() const

    {

        return 0;

    }

    virtual size_t Write(const void *pBuffer, size_t nSize, size_t nCount) = 0;

    int Printf(CPL_FORMAT_STRING(const char *pszFormat), ...)

        CPL_PRINT_FUNC_FORMAT(2, 3);

    virtual void ClearErr() = 0;

    virtual int Eof() = 0;

    virtual int Error() = 0;

    virtual int Flush()

    {

        return 0;

    }

    virtual int Close() = 0;

    // Base implementation that only supports file extension.

    virtual int Truncate(vsi_l_offset nNewSize);

    virtual void *GetNativeFileDescriptor()

    {

        return nullptr;

    }

    virtual VSIRangeStatus GetRangeStatus(CPL_UNUSED vsi_l_offset nOffset,

                                          CPL_UNUSED vsi_l_offset nLength)

    {

        return VSI_RANGE_STATUS_UNKNOWN;

    }

    virtual bool HasPRead() const;

    virtual size_t PRead(void *pBuffer, size_t nSize,

                         vsi_l_offset nOffset) const;

    /** Ask current operations to be interrupted.

     * Implementations must be thread-safe, as this will typically be called

     * from another thread than the active one for this file.

     */

    virtual void Interrupt()

    {

    }

    /** For a file created with CreateOnlyVisibleAtCloseTime(), ask for the

     * file to not be created at all (if possible)

     */

    virtual void CancelCreation()

    {

    }

    // NOTE: when adding new methods, besides the "actual" implementations,

    // also consider the VSICachedFile and VSIVirtualHandleOnlyVisibleAtCloseTime one.

    virtual ~VSIVirtualHandle()

    {

    }

};

/************************************************************************/

/*                        VSIVirtualHandleCloser                        */

/************************************************************************/

/** Helper close to use with a std:unique_ptr<VSIVirtualHandle>,

 *  such as VSIVirtualHandleUniquePtr. */

struct VSIVirtualHandleCloser

{

    /** Operator () that closes and deletes the file handle. */

    void operator()(VSIVirtualHandle *poHandle)

    {

        if (poHandle)

        {

            poHandle->Close();

            delete poHandle;

        }

    }

};

/** Unique pointer of VSIVirtualHandle that calls the Close() method */

typedef std::unique_ptr<VSIVirtualHandle, VSIVirtualHandleCloser>

    VSIVirtualHandleUniquePtr;

/************************************************************************/

/*                        VSIProxyFileHandle                            */

/************************************************************************/

#ifndef DOXYGEN_SKIP

class VSIProxyFileHandle /* non final */ : public VSIVirtualHandle

{

  protected:

    VSIVirtualHandleUniquePtr m_nativeHandle{};

  public:

    explicit VSIProxyFileHandle(VSIVirtualHandleUniquePtr &&nativeHandle)

        : m_nativeHandle(std::move(nativeHandle))

    {

    }

    int Seek(vsi_l_offset nOffset, int nWhence) override

    {

        return m_nativeHandle->Seek(nOffset, nWhence);

    }

    vsi_l_offset Tell() override

    {

        return m_nativeHandle->Tell();

    }

    size_t Read(void *pBuffer, size_t nSize, size_t nCount) override

    {

        return m_nativeHandle->Read(pBuffer, nSize, nCount);

    }

    int ReadMultiRange(int nRanges, void **ppData,

                       const vsi_l_offset *panOffsets,

                       const size_t *panSizes) override

    {

        return m_nativeHandle->ReadMultiRange(nRanges, ppData, panOffsets,

                                              panSizes);

    }

    void AdviseRead(int nRanges, const vsi_l_offset *panOffsets,

                    const size_t *panSizes) override

    {

        return m_nativeHandle->AdviseRead(nRanges, panOffsets, panSizes);

    }

    size_t GetAdviseReadTotalBytesLimit() const override

    {

        return m_nativeHandle->GetAdviseReadTotalBytesLimit();

    }

    size_t Write(const void *pBuffer, size_t nSize, size_t nCount) override

    {

        return m_nativeHandle->Write(pBuffer, nSize, nCount);

    }

    void ClearErr() override

    {

        return m_nativeHandle->ClearErr();

    }

    int Eof() override

    {

        return m_nativeHandle->Eof();

    }

    int Error() override

    {

        return m_nativeHandle->Error();

    }

    int Flush() override

    {

        return m_nativeHandle->Flush();

    }

    int Close() override

    {

        return m_nativeHandle->Close();

    }

    int Truncate(vsi_l_offset nNewSize) override

    {

        return m_nativeHandle->Truncate(nNewSize);

    }

    void *GetNativeFileDescriptor() override

    {

        return m_nativeHandle->GetNativeFileDescriptor();

    }

    VSIRangeStatus GetRangeStatus(vsi_l_offset nOffset,

                                  vsi_l_offset nLength) override

    {

        return m_nativeHandle->GetRangeStatus(nOffset, nLength);

    }

    bool HasPRead() const override

    {

        return m_nativeHandle->HasPRead();

    }

    size_t PRead(void *pBuffer, size_t nSize,

                 vsi_l_offset nOffset) const override

    {

        return m_nativeHandle->PRead(pBuffer, nSize, nOffset);

    }

    void Interrupt() override

    {

        m_nativeHandle->Interrupt();

    }

    void CancelCreation() override;

};

#endif

/************************************************************************/

/*                         VSIFilesystemHandler                         */

/************************************************************************/

#ifndef DOXYGEN_SKIP

class CPL_DLL VSIFilesystemHandler

{

  public:

    virtual ~VSIFilesystemHandler() = default;

    static VSIVirtualHandleUniquePtr

    OpenStatic(const char *pszFilename, const char *pszAccess,

               bool bSetError = false, CSLConstList papszOptions = nullptr);

    virtual VSIVirtualHandleUniquePtr

    Open(const char *pszFilename, const char *pszAccess, bool bSetError = false,

         CSLConstList papszOptions = nullptr) = 0;

    virtual VSIVirtualHandleUniquePtr

    CreateOnlyVisibleAtCloseTime(const char *pszFilename,

                                 bool bEmulationAllowed,

                                 CSLConstList papszOptions);

    virtual int Stat(const char *pszFilename, VSIStatBufL *pStatBuf,

                     int nFlags) = 0;

    virtual int Unlink(const char *pszFilename)

    {

        (void)pszFilename;

        errno = ENOENT;

        return -1;

    }

    virtual int *UnlinkBatch(CSLConstList papszFiles);

    virtual int Mkdir(const char *pszDirname, long nMode)

    {

        (void)pszDirname;

        (void)nMode;

        errno = ENOENT;

        return -1;

    }

    virtual int Rmdir(const char *pszDirname)

    {

        (void)pszDirname;

        errno = ENOENT;

        return -1;

    }

    virtual int RmdirRecursive(const char *pszDirname);

    char **ReadDir(const char *pszDirname)

    {

        return ReadDirEx(pszDirname, 0);

    }

    virtual char **ReadDirEx(const char * /*pszDirname*/, int /* nMaxFiles */)

    {

        return nullptr;

    }

    virtual char **SiblingFiles(const char * /*pszFilename*/)

    {

        return nullptr;

    }

    virtual int Rename(const char *oldpath, const char *newpath,

                       GDALProgressFunc pProgressFunc, void *pProgressData)

    {

        (void)oldpath;

        (void)newpath;

        (void)pProgressFunc;

        (void)pProgressData;

        errno = ENOENT;

        return -1;

    }

    virtual int IsCaseSensitive(const char *pszFilename)

    {

        (void)pszFilename;

        return TRUE;

    }

    virtual GIntBig GetDiskFreeSpace(const char * /* pszDirname */)

    {

        return -1;

    }

    virtual int SupportsSparseFiles(const char * /* pszPath */)

    {

        return FALSE;

    }

    virtual int HasOptimizedReadMultiRange(const char * /* pszPath */)

    {

        return FALSE;

    }

    virtual const char *GetActualURL(const char * /*pszFilename*/)

    {

        return nullptr;

    }

    virtual const char *GetOptions()

    {

        return nullptr;

    }

    virtual char *GetSignedURL(const char * /*pszFilename*/,

                               CSLConstList /* papszOptions */)

    {

        return nullptr;

    }

    virtual bool Sync(const char *pszSource, const char *pszTarget,

                      const char *const *papszOptions,

                      GDALProgressFunc pProgressFunc, void *pProgressData,

                      char ***ppapszOutputs);

    virtual int CopyFile(const char *pszSource, const char *pszTarget,

                         VSILFILE *fpSource, vsi_l_offset nSourceSize,

                         const char *const *papszOptions,

                         GDALProgressFunc pProgressFunc, void *pProgressData);

    virtual int

    CopyFileRestartable(const char *pszSource, const char *pszTarget,

                        const char *pszInputPayload, char **ppszOutputPayload,

                        CSLConstList papszOptions,

                        GDALProgressFunc pProgressFunc, void *pProgressData);

    virtual VSIDIR *OpenDir(const char *pszPath, int nRecurseDepth,

                            const char *const *papszOptions);

    virtual char **GetFileMetadata(const char *pszFilename,

                                   const char *pszDomain,

                                   CSLConstList papszOptions);

    virtual bool SetFileMetadata(const char *pszFilename,

                                 CSLConstList papszMetadata,

                                 const char *pszDomain,

                                 CSLConstList papszOptions);

    virtual bool

    MultipartUploadGetCapabilities(int *pbNonSequentialUploadSupported,

                                   int *pbParallelUploadSupported,

                                   int *pbAbortSupported, size_t *pnMinPartSize,

                                   size_t *pnMaxPartSize, int *pnMaxPartCount);

    virtual char *MultipartUploadStart(const char *pszFilename,

                                       CSLConstList papszOptions);

    virtual char *MultipartUploadAddPart(const char *pszFilename,

                                         const char *pszUploadId,

                                         int nPartNumber,

                                         vsi_l_offset nFileOffset,

                                         const void *pData, size_t nDataLength,

                                         CSLConstList papszOptions);

    virtual bool

    MultipartUploadEnd(const char *pszFilename, const char *pszUploadId,

                       size_t nPartIdsCount, const char *const *apszPartIds,

                       vsi_l_offset nTotalSize, CSLConstList papszOptions);

    virtual bool MultipartUploadAbort(const char *pszFilename,

                                      const char *pszUploadId,

                                      CSLConstList papszOptions);

    virtual bool AbortPendingUploads(const char * /*pszFilename*/)

    {

        return true;

    }

    virtual std::string

    GetStreamingFilename(const std::string &osFilename) const

    {

        return osFilename;

    }

    virtual std::string

    GetNonStreamingFilename(const std::string &osFilename) const

    {

        return osFilename;

    }

    /** Return the canonical filename.

     *

     * May be implemented by case-insensitive filesystems

     * (currently Win32 and MacOSX)

     * to return the filename with its actual case (i.e. the one that would

     * be used when listing the content of the directory).

     */

    virtual std::string

    GetCanonicalFilename(const std::string &osFilename) const

    {

        return osFilename;

    }

    virtual bool IsLocal(const char * /* pszPath */) const

    {

        return true;

    }

    virtual bool IsArchive(const char * /* pszPath */) const

    {

        return false;

    }

    virtual bool SupportsSequentialWrite(const char * /* pszPath */,

                                         bool /* bAllowLocalTempFile */)

    {

        return true;

    }

    virtual bool SupportsRandomWrite(const char * /* pszPath */,

                                     bool /* bAllowLocalTempFile */)

    {

        return true;

    }

    virtual bool SupportsRead(const char * /* pszPath */)

    {

        return true;

    }

    virtual VSIFilesystemHandler *Duplicate(const char * /* pszPrefix */)

    {

        CPLError(CE_Failure, CPLE_NotSupported,

                 "Duplicate() not supported on this file "

                 "system");

        return nullptr;

    }

    /** Return the directory separator.

     *

     * Default is forward slash. The only exception currently is the Windows

     * file system which returns anti-slash, unless the specified path is of the

     * form "{drive_letter}:/{rest_of_the_path}".

     */

    virtual const char *GetDirectorySeparator(CPL_UNUSED const char *pszPath)

    {

        return "/";

    }

};

#endif /* #ifndef DOXYGEN_SKIP */

/************************************************************************/

/*                            VSIFileManager                            */

/************************************************************************/

#ifndef DOXYGEN_SKIP

class CPL_DLL VSIFileManager

{

  private:

    VSIFilesystemHandler *poDefaultHandler = nullptr;

    std::map<std::string, VSIFilesystemHandler *> oHandlers{};

    VSIFileManager();

    static VSIFileManager *Get();

    CPL_DISALLOW_COPY_ASSIGN(VSIFileManager)

  public:

    ~VSIFileManager();

    static VSIFilesystemHandler *GetHandler(const char *);

    static void InstallHandler(const std::string &osPrefix,

                               VSIFilesystemHandler *);

    static void RemoveHandler(const std::string &osPrefix);

    static char **GetPrefixes();

};

#endif /* #ifndef DOXYGEN_SKIP */

/************************************************************************/

/* ==================================================================== */

/*                       VSIArchiveFilesystemHandler                   */

/* ==================================================================== */

/************************************************************************/

#ifndef DOXYGEN_SKIP

class VSIArchiveEntryFileOffset

{

  public:

    virtual ~VSIArchiveEntryFileOffset();

};

class VSIArchiveEntry

{

  public:

    std::string fileName{};

    vsi_l_offset uncompressed_size = 0;

    std::unique_ptr<VSIArchiveEntryFileOffset> file_pos{};

    bool bIsDir = false;

    GIntBig nModifiedTime = 0;

};

class VSIArchiveContent

{

  public:

    time_t mTime = 0;

    vsi_l_offset nFileSize = 0;

    std::vector<VSIArchiveEntry> entries{};

    // Store list of child indices for each directory

    using DirectoryChildren = std::vector<int>;

    std::map<std::string, DirectoryChildren> dirIndex{};

    VSIArchiveContent() = default;

    ~VSIArchiveContent();

  private:

    CPL_DISALLOW_COPY_ASSIGN(VSIArchiveContent)

};

class VSIArchiveReader

{

  public:

    virtual ~VSIArchiveReader();

    virtual int GotoFirstFile() = 0;

    virtual int GotoNextFile() = 0;

    virtual VSIArchiveEntryFileOffset *GetFileOffset() = 0;

    virtual GUIntBig GetFileSize() = 0;

    virtual CPLString GetFileName() = 0;

    virtual GIntBig GetModifiedTime() = 0;

    virtual int GotoFileOffset(VSIArchiveEntryFileOffset *pOffset) = 0;

};

class VSIArchiveFilesystemHandler /* non final */ : public VSIFilesystemHandler

{

    CPL_DISALLOW_COPY_ASSIGN(VSIArchiveFilesystemHandler)

    bool FindFileInArchive(const char *archiveFilename,

                           const char *fileInArchiveName,

                           const VSIArchiveEntry **archiveEntry);

  protected:

    mutable std::recursive_mutex oMutex{};

    /* We use a cache that contains the list of files contained in a VSIArchive

     * file as */

    /* unarchive.c is quite inefficient in listing them. This speeds up access

     * to VSIArchive files */

    /* containing ~1000 files like a CADRG product */

    std::map<CPLString, std::unique_ptr<VSIArchiveContent>> oFileList{};

    virtual const char *GetPrefix() const = 0;

    virtual std::vector<CPLString> GetExtensions() const = 0;

    virtual std::unique_ptr<VSIArchiveReader>

    CreateReader(const char *pszArchiveFileName) = 0;

  public:

    VSIArchiveFilesystemHandler();

    ~VSIArchiveFilesystemHandler() override;

    int Stat(const char *pszFilename, VSIStatBufL *pStatBuf,

             int nFlags) override;

    char **ReadDirEx(const char *pszDirname, int nMaxFiles) override;

    virtual const VSIArchiveContent *

    GetContentOfArchive(const char *archiveFilename,

                        VSIArchiveReader *poReader = nullptr);

    virtual char *SplitFilename(const char *pszFilename,

                                CPLString &osFileInArchive,

                                bool bCheckMainFileExists,

                                bool bSetError) const;

    virtual std::unique_ptr<VSIArchiveReader>

    OpenArchiveFile(const char *archiveFilename, const char *fileInArchiveName);

    bool IsLocal(const char *pszPath) const override;

    bool IsArchive(const char *pszPath) const override;

    bool SupportsSequentialWrite(const char * /* pszPath */,

                                 bool /* bAllowLocalTempFile */) override

    {

        return false;

    }

    bool SupportsRandomWrite(const char * /* pszPath */,

                             bool /* bAllowLocalTempFile */) override

    {

        return false;

    }

};

/************************************************************************/

/*                              VSIDIR                                  */

/************************************************************************/

struct CPL_DLL VSIDIR

{

    VSIDIR() = default;

    virtual ~VSIDIR();

    virtual const VSIDIREntry *NextDirEntry() = 0;

  private:

    VSIDIR(const VSIDIR &) = delete;

    VSIDIR &operator=(const VSIDIR &) = delete;

};

#endif /* #ifndef DOXYGEN_SKIP */

VSIVirtualHandle CPL_DLL *

VSICreateBufferedReaderHandle(VSIVirtualHandle *poBaseHandle);

VSIVirtualHandle *

VSICreateBufferedReaderHandle(VSIVirtualHandle *poBaseHandle,

                              const GByte *pabyBeginningContent,

                              vsi_l_offset nCheatFileSize);

constexpr int VSI_CACHED_DEFAULT_CHUNK_SIZE = 32768;

VSIVirtualHandle CPL_DLL *

VSICreateCachedFile(VSIVirtualHandle *poBaseHandle,

                    size_t nChunkSize = VSI_CACHED_DEFAULT_CHUNK_SIZE,

                    size_t nCacheSize = 0);

const int CPL_DEFLATE_TYPE_GZIP = 0;

const int CPL_DEFLATE_TYPE_ZLIB = 1;

const int CPL_DEFLATE_TYPE_RAW_DEFLATE = 2;

VSIVirtualHandle CPL_DLL *VSICreateGZipWritable(VSIVirtualHandle *poBaseHandle,

                                                int nDeflateType,

                                                int bAutoCloseBaseHandle);

VSIVirtualHandle *VSICreateGZipWritable(VSIVirtualHandle *poBaseHandle,

                                        int nDeflateType,

                                        bool bAutoCloseBaseHandle, int nThreads,

                                        size_t nChunkSize,

                                        size_t nSOZIPIndexEltSize,

                                        std::vector<uint8_t> *panSOZIPIndex);

VSIVirtualHandle *

VSICreateUploadOnCloseFile(VSIVirtualHandleUniquePtr &&poWritableHandle,

                           VSIVirtualHandleUniquePtr &&poTmpFile,

                           const std::string &osTmpFilename);

#endif /* ndef CPL_VSI_VIRTUAL_H_INCLUDED */