/*

 * LZMA support routines for PhysicsFS.

 *

 * Please see the file lzma.txt in the lzma/ directory.

 *

 *  This file was written by Dennis Schridde, with some peeking at "7zMain.c"

 *   by Igor Pavlov.

 */

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

#include "lzma/C/7zCrc.h"

#include "lzma/C/Archive/7z/7zIn.h"

#include "lzma/C/Archive/7z/7zExtract.h"

/* 7z internal from 7zIn.c */

extern int TestSignatureCandidate(Byte *testBytes);

#ifdef _LZMA_IN_CB

# define BUFFER_SIZE (1 << 12)

#endif /* _LZMA_IN_CB */

/*

 * Carries filestream metadata through 7z

 */

typedef struct _FileInputStream

{

    ISzAlloc allocImp; /* Allocation implementation, used by 7z */

    ISzAlloc allocTempImp; /* Temporary allocation implementation, used by 7z */

    ISzInStream inStream; /* Input stream with read callbacks, used by 7z */

    PHYSFS_Io *io;  /* Filehandle, used by read implementation */

#ifdef _LZMA_IN_CB

    Byte buffer[BUFFER_SIZE]; /* Buffer, used by read implementation */

#endif /* _LZMA_IN_CB */

} FileInputStream;

/*

 * In the 7z format archives are splited into blocks, those are called folders

 * Set by LZMA_read()

*/

typedef struct _LZMAfolder

{

    PHYSFS_uint32 index; /* Index of folder in archive */

    PHYSFS_uint32 references; /* Number of files using this block */

    PHYSFS_uint8 *cache; /* Cached folder */

    size_t size; /* Size of folder */

} LZMAfolder;

/*

 * Set by LZMA_openArchive(), except folder which gets it's values

 *  in LZMA_read()

 */

typedef struct _LZMAarchive

{

    struct _LZMAfile *files; /* Array of files, size == archive->db.Database.NumFiles */

    LZMAfolder *folders; /* Array of folders, size == archive->db.Database.NumFolders */

    CArchiveDatabaseEx db; /* For 7z: Database */

    FileInputStream stream; /* For 7z: Input file incl. read and seek callbacks */

} LZMAarchive;

/* Set by LZMA_openArchive(), except offset which is set by LZMA_read() */

typedef struct _LZMAfile

{

    PHYSFS_uint32 index; /* Index of file in archive */

    LZMAarchive *archive; /* Link to corresponding archive */

    LZMAfolder *folder; /* Link to corresponding folder */

    CFileItem *item; /* For 7z: File info, eg. name, size */

    size_t offset; /* Offset in folder */

    size_t position; /* Current "virtual" position in file */

} LZMAfile;

/* Memory management implementations to be passed to 7z */

static void *SzAllocPhysicsFS(size_t size)

{

    return ((size == 0) ? NULL : allocator.Malloc(size));

} /* SzAllocPhysicsFS */

static void SzFreePhysicsFS(void *address)

{

    if (address != NULL)

        allocator.Free(address);

} /* SzFreePhysicsFS */

/* Filesystem implementations to be passed to 7z */

#ifdef _LZMA_IN_CB

/*

 * Read implementation, to be passed to 7z

 * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!

 */

SZ_RESULT SzFileReadImp(void *object, void **buffer, size_t maxReqSize,

                        size_t *processedSize)

{

    FileInputStream *s = (FileInputStream *)(object - offsetof(FileInputStream, inStream)); /* HACK! */

    PHYSFS_sint64 processedSizeLoc = 0;

    if (maxReqSize > BUFFER_SIZE)

        maxReqSize = BUFFER_SIZE;

    processedSizeLoc = s->io->read(s->io, s->buffer, maxReqSize);

    *buffer = s->buffer;

    if (processedSize != NULL)

        *processedSize = (size_t) processedSizeLoc;

    return SZ_OK;

} /* SzFileReadImp */

#else

/*

 * Read implementation, to be passed to 7z

 * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!

 */

SZ_RESULT SzFileReadImp(void *object, void *buffer, size_t size,

                        size_t *processedSize)

{

    FileInputStream *s = (FileInputStream *)((unsigned long)object - offsetof(FileInputStream, inStream)); /* HACK! */

    const size_t processedSizeLoc = s->io->read(s->io, buffer, size);

    if (processedSize != NULL)

        *processedSize = processedSizeLoc;

    return SZ_OK;

} /* SzFileReadImp */

#endif

/*

 * Seek implementation, to be passed to 7z

 * WARNING: If the ISzInStream in 'object' is not contained in a valid FileInputStream this _will_ break horribly!

 */

SZ_RESULT SzFileSeekImp(void *object, CFileSize pos)

{

    FileInputStream *s = (FileInputStream *)((unsigned long)object - offsetof(FileInputStream, inStream)); /* HACK! */

    if (s->io->seek(s->io, (PHYSFS_uint64) pos))

        return SZ_OK;

    return SZE_FAIL;

} /* SzFileSeekImp */

/*

 * Translate Microsoft FILETIME (used by 7zip) into UNIX timestamp

 */

static PHYSFS_sint64 lzma_filetime_to_unix_timestamp(CArchiveFileTime *ft)

{

    /* MS counts in nanoseconds ... */

    const PHYSFS_uint64 FILETIME_NANOTICKS_PER_SECOND = __PHYSFS_UI64(10000000);

    /* MS likes to count seconds since 01.01.1601 ... */

    const PHYSFS_uint64 FILETIME_UNIX_DIFF = __PHYSFS_UI64(11644473600);

    PHYSFS_uint64 filetime = ft->Low | ((PHYSFS_uint64)ft->High << 32);

    return filetime/FILETIME_NANOTICKS_PER_SECOND - FILETIME_UNIX_DIFF;

} /* lzma_filetime_to_unix_timestamp */

/*

 * Compare a file with a given name, C89 stdlib variant

 * Used for sorting

 */

static int lzma_file_cmp_stdlib(const void *key, const void *object)

{

    const char *name = (const char *) key;

    LZMAfile *file = (LZMAfile *) object;

    return strcmp(name, file->item->Name);

} /* lzma_file_cmp_posix */

/*

 * Compare two files with each other based on the name

 * Used for sorting

 */

static int lzma_file_cmp(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 two)

{

    LZMAfile *files = (LZMAfile *) _a;

    return strcmp(files[one].item->Name, files[two].item->Name);

} /* lzma_file_cmp */

/*

 * Swap two entries in the file array

 */

static void lzma_file_swap(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 two)

{

    LZMAfile tmp;

    LZMAfile *first = &(((LZMAfile *) _a)[one]);

    LZMAfile *second = &(((LZMAfile *) _a)[two]);

    memcpy(&tmp, first, sizeof (LZMAfile));

    memcpy(first, second, sizeof (LZMAfile));

    memcpy(second, &tmp, sizeof (LZMAfile));

} /* lzma_file_swap */

/*

 * Find entry 'name' in 'archive'

 */

static LZMAfile * lzma_find_file(const LZMAarchive *archive, const char *name)

{

    LZMAfile *file = bsearch(name, archive->files, archive->db.Database.NumFiles, sizeof(*archive->files), lzma_file_cmp_stdlib); /* FIXME: Should become __PHYSFS_search!!! */

    BAIL_IF_MACRO(file == NULL, PHYSFS_ERR_NO_SUCH_PATH, NULL);

    return file;

} /* lzma_find_file */

/*

 * Load metadata for the file at given index

 */

static int lzma_file_init(LZMAarchive *archive, PHYSFS_uint32 fileIndex)

{

    LZMAfile *file = &archive->files[fileIndex];

    PHYSFS_uint32 folderIndex = archive->db.FileIndexToFolderIndexMap[fileIndex];

    file->index = fileIndex; /* Store index into 7z array, since we sort our own. */

    file->archive = archive;

    file->folder = (folderIndex != (PHYSFS_uint32)-1 ? &archive->folders[folderIndex] : NULL); /* Directories don't have a folder (they contain no own data...) */

    file->item = &archive->db.Database.Files[fileIndex]; /* Holds crucial data and is often referenced -> Store link */

    file->position = 0;

    file->offset = 0; /* Offset will be set by LZMA_read() */

    return 1;

} /* lzma_load_file */

/*

 * Load metadata for all files

 */

static int lzma_files_init(LZMAarchive *archive)

{

    PHYSFS_uint32 fileIndex = 0, numFiles = archive->db.Database.NumFiles;

    for (fileIndex = 0; fileIndex < numFiles; fileIndex++ )

    {

        if (!lzma_file_init(archive, fileIndex))

        {

            return 0; /* FALSE on failure */

        }

    } /* for */

   __PHYSFS_sort(archive->files, numFiles, lzma_file_cmp, lzma_file_swap);

    return 1;

} /* lzma_load_files */

/*

 * Initialise specified archive

 */

static void lzma_archive_init(LZMAarchive *archive)

{

    memset(archive, 0, sizeof(*archive));

    /* Prepare callbacks for 7z */

    archive->stream.inStream.Read = SzFileReadImp;

    archive->stream.inStream.Seek = SzFileSeekImp;

    archive->stream.allocImp.Alloc = SzAllocPhysicsFS;

    archive->stream.allocImp.Free = SzFreePhysicsFS;

    archive->stream.allocTempImp.Alloc = SzAllocPhysicsFS;

    archive->stream.allocTempImp.Free = SzFreePhysicsFS;

}

/*

 * Deinitialise archive

 */

static void lzma_archive_exit(LZMAarchive *archive)

{

    /* Free arrays */

    allocator.Free(archive->folders);

    allocator.Free(archive->files);

    allocator.Free(archive);

}

/*

 * Wrap all 7z calls in this, so the physfs error state is set appropriately.

 */

static int lzma_err(SZ_RESULT rc)

{

    switch (rc)

    {

        case SZ_OK: /* Same as LZMA_RESULT_OK */

            break;

        case SZE_DATA_ERROR: /* Same as LZMA_RESULT_DATA_ERROR */

            __PHYSFS_setError(PHYSFS_ERR_CORRUPT); /*!!!FIXME: was "PHYSFS_ERR_DATA_ERROR" */

            break;

        case SZE_OUTOFMEMORY:

            __PHYSFS_setError(PHYSFS_ERR_OUT_OF_MEMORY);

            break;

        case SZE_CRC_ERROR:

            __PHYSFS_setError(PHYSFS_ERR_CORRUPT);

            break;

        case SZE_NOTIMPL:

            __PHYSFS_setError(PHYSFS_ERR_UNSUPPORTED);

            break;

        case SZE_FAIL:

            __PHYSFS_setError(PHYSFS_ERR_OTHER_ERROR);  /* !!! FIXME: right? */

            break;

        case SZE_ARCHIVE_ERROR:

            __PHYSFS_setError(PHYSFS_ERR_CORRUPT);  /* !!! FIXME: right? */

            break;

        default:

            __PHYSFS_setError(PHYSFS_ERR_OTHER_ERROR);

    } /* switch */

    return rc;

} /* lzma_err */

static PHYSFS_sint64 LZMA_read(PHYSFS_Io *io, void *outBuf, PHYSFS_uint64 len)

{

    LZMAfile *file = (LZMAfile *) io->opaque;

    size_t wantedSize = (size_t) len;

    const size_t remainingSize = file->item->Size - file->position;

    size_t fileSize = 0;

    BAIL_IF_MACRO(wantedSize == 0, ERRPASS, 0); /* quick rejection. */

    BAIL_IF_MACRO(remainingSize == 0, PHYSFS_ERR_PAST_EOF, 0);

    if (wantedSize > remainingSize)

        wantedSize = remainingSize;

    /* Only decompress the folder if it is not already cached */

    if (file->folder->cache == NULL)

    {

        const int rc = lzma_err(SzExtract(

            &file->archive->stream.inStream, /* compressed data */

            &file->archive->db, /* 7z's database, containing everything */

            file->index, /* Index into database arrays */

            /* Index of cached folder, will be changed by SzExtract */

            &file->folder->index,

            /* Cache for decompressed folder, allocated/freed by SzExtract */

            &file->folder->cache,

            /* Size of cache, will be changed by SzExtract */

            &file->folder->size,

            /* Offset of this file inside the cache, set by SzExtract */

            &file->offset,

            &fileSize, /* Size of this file */

            &file->archive->stream.allocImp,

            &file->archive->stream.allocTempImp));

        if (rc != SZ_OK)

            return -1;

    } /* if */

    /* Copy wanted bytes over from cache to outBuf */

    memcpy(outBuf, (file->folder->cache + file->offset + file->position),

            wantedSize);

    file->position += wantedSize; /* Increase virtual position */

    return wantedSize;

} /* LZMA_read */

static PHYSFS_sint64 LZMA_write(PHYSFS_Io *io, const void *b, PHYSFS_uint64 len)

{

    BAIL_MACRO(PHYSFS_ERR_READ_ONLY, -1);

} /* LZMA_write */

static PHYSFS_sint64 LZMA_tell(PHYSFS_Io *io)

{

    LZMAfile *file = (LZMAfile *) io->opaque;

    return file->position;

} /* LZMA_tell */

static int LZMA_seek(PHYSFS_Io *io, PHYSFS_uint64 offset)

{

    LZMAfile *file = (LZMAfile *) io->opaque;

    BAIL_IF_MACRO(offset > file->item->Size, PHYSFS_ERR_PAST_EOF, 0);

    file->position = offset; /* We only use a virtual position... */

    return 1;

} /* LZMA_seek */

static PHYSFS_sint64 LZMA_length(PHYSFS_Io *io)

{

    const LZMAfile *file = (LZMAfile *) io->opaque;

    return (file->item->Size);

} /* LZMA_length */

static PHYSFS_Io *LZMA_duplicate(PHYSFS_Io *_io)

{

    /* !!! FIXME: this archiver needs to be reworked to allow multiple

     * !!! FIXME:  opens before we worry about duplication. */

    BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);

} /* LZMA_duplicate */

static int LZMA_flush(PHYSFS_Io *io) { return 1;  /* no write support. */ }

static void LZMA_destroy(PHYSFS_Io *io)

{

    LZMAfile *file = (LZMAfile *) io->opaque;

    if (file->folder != NULL)

    {

        /* Only decrease refcount if someone actually requested this file... Prevents from overflows and close-on-open... */

        if (file->folder->references > 0)

            file->folder->references--;

        if (file->folder->references == 0)

        {

            /* Free the cache which might have been allocated by LZMA_read() */

            allocator.Free(file->folder->cache);

            file->folder->cache = NULL;

        }

        /* !!! FIXME: we don't free (file) or (file->folder)?! */

    } /* if */

} /* LZMA_destroy */

static const PHYSFS_Io LZMA_Io =

{

    LZMA_read,

    LZMA_write,

    LZMA_seek,

    LZMA_tell,

    LZMA_length,

    LZMA_duplicate,

    LZMA_flush,

    LZMA_destroy,

    NULL

};

static void *LZMA_openArchive(PHYSFS_Io *io, const char *name, int forWriting)

{

    PHYSFS_uint8 sig[k7zSignatureSize];

    size_t len = 0;

    LZMAarchive *archive = NULL;

    assert(io != NULL);  /* shouldn't ever happen. */

    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);

    if (io->read(io, sig, k7zSignatureSize) != k7zSignatureSize)

        return 0;

    BAIL_IF_MACRO(!TestSignatureCandidate(sig), PHYSFS_ERR_UNSUPPORTED, NULL);

    BAIL_IF_MACRO(!io->seek(io, 0), ERRPASS, NULL);

    archive = (LZMAarchive *) allocator.Malloc(sizeof (LZMAarchive));

    BAIL_IF_MACRO(archive == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    lzma_archive_init(archive);

    archive->stream.io = io;

    CrcGenerateTable();

    SzArDbExInit(&archive->db);

    if (lzma_err(SzArchiveOpen(&archive->stream.inStream,

                               &archive->db,

                               &archive->stream.allocImp,

                               &archive->stream.allocTempImp)) != SZ_OK)

    {

        SzArDbExFree(&archive->db, SzFreePhysicsFS);

        lzma_archive_exit(archive);

        return NULL; /* Error is set by lzma_err! */

    } /* if */

    len = archive->db.Database.NumFiles * sizeof (LZMAfile);

    archive->files = (LZMAfile *) allocator.Malloc(len);

    if (archive->files == NULL)

    {

        SzArDbExFree(&archive->db, SzFreePhysicsFS);

        lzma_archive_exit(archive);

        BAIL_MACRO(PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    }

    /*

     * Init with 0 so we know when a folder is already cached

     * Values will be set by LZMA_openRead()

     */

    memset(archive->files, 0, len);