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/*

 * 7zip support routines for PhysicsFS.

 *

 * Please see the file LICENSE.txt in the source's root directory.

 *

 *  This file was written by Ryan C. Gordon.

 */

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

#if PHYSFS_SUPPORTS_7Z

#include "physfs_lzmasdk.h"

typedef struct

{

    ISeekInStream seekStream; /* lzma sdk i/o interface (lower level).  */

    PHYSFS_Io *io;            /* physfs i/o interface for this archive. */

    CLookToRead lookStream;   /* lzma sdk i/o interface (higher level). */

} SZIPLookToRead;

/* One SZIPentry is kept for each file in an open 7zip archive. */

typedef struct

{

    __PHYSFS_DirTreeEntry tree;   /* manages directory tree         */

    PHYSFS_uint32 dbidx;          /* index into lzma sdk database   */

} SZIPentry;

/* One SZIPinfo is kept for each open 7zip archive. */

typedef struct

{

    __PHYSFS_DirTree tree;    /* manages directory tree.           */

    PHYSFS_Io *io;            /* physfs i/o interface for this archive. */

    CSzArEx db;               /* lzma sdk archive database object. */

} SZIPinfo;

static PHYSFS_ErrorCode szipErrorCode(const SRes rc)

{

    switch (rc)

    {

        case SZ_OK: return PHYSFS_ERR_OK;

        case SZ_ERROR_DATA: return PHYSFS_ERR_CORRUPT;

        case SZ_ERROR_MEM: return PHYSFS_ERR_OUT_OF_MEMORY;

        case SZ_ERROR_CRC: return PHYSFS_ERR_CORRUPT;

        case SZ_ERROR_UNSUPPORTED: return PHYSFS_ERR_UNSUPPORTED;

        case SZ_ERROR_INPUT_EOF: return PHYSFS_ERR_CORRUPT;

        case SZ_ERROR_OUTPUT_EOF: return PHYSFS_ERR_IO;

        case SZ_ERROR_READ: return PHYSFS_ERR_IO;

        case SZ_ERROR_WRITE: return PHYSFS_ERR_IO;

        case SZ_ERROR_ARCHIVE: return PHYSFS_ERR_CORRUPT;

        case SZ_ERROR_NO_ARCHIVE: return PHYSFS_ERR_UNSUPPORTED;

        default: break;

    } /* switch */

    return PHYSFS_ERR_OTHER_ERROR;

} /* szipErrorCode */

/* LZMA SDK's ISzAlloc interface ... */

static void *SZIP_ISzAlloc_Alloc(void *p, size_t size)

{

    return allocator.Malloc(size ? size : 1);

} /* SZIP_ISzAlloc_Alloc */

static void SZIP_ISzAlloc_Free(void *p, void *address)

{

    if (address)

        allocator.Free(address);

} /* SZIP_ISzAlloc_Free */

static ISzAlloc SZIP_SzAlloc = {

    SZIP_ISzAlloc_Alloc, SZIP_ISzAlloc_Free

};

/* we implement ISeekInStream, and then wrap that in LZMA SDK's CLookToRead,

   which implements the higher-level ILookInStream on top of that, handling

   buffering and such for us. */

/* LZMA SDK's ISeekInStream interface ... */

static SRes SZIP_ISeekInStream_Read(void *p, void *buf, size_t *size)

{

    SZIPLookToRead *stream = (SZIPLookToRead *) p;

    PHYSFS_Io *io = stream->io;

    const PHYSFS_uint64 len = (PHYSFS_uint64) *size;

    const PHYSFS_sint64 rc = (len == 0) ? 0 : io->read(io, buf, len);

    if (rc < 0)

    {

        *size = 0;

        return SZ_ERROR_READ;

    } /* if */

    *size = (size_t) rc;

    return SZ_OK;

} /* SZIP_ISeekInStream_Read */

static SRes SZIP_ISeekInStream_Seek(void *p, Int64 *pos, ESzSeek origin)

{

    SZIPLookToRead *stream = (SZIPLookToRead *) p;

    PHYSFS_Io *io = stream->io;

    PHYSFS_sint64 base;

    PHYSFS_uint64 newpos;

    switch (origin)

    {

        case SZ_SEEK_SET:

            base = 0;

            break;

        case SZ_SEEK_CUR:

            base = io->tell(io);

            break;

        case SZ_SEEK_END:

            base = io->length(io);

            break;

        default:

            return SZ_ERROR_FAIL;

    } /* switch */

    if (base < 0)

        return SZ_ERROR_FAIL;

    else if ((*pos < 0) && (((Int64) base) < -*pos))

        return SZ_ERROR_FAIL;

    newpos = (PHYSFS_uint64) (((Int64) base) + *pos);

    if (!io->seek(io, newpos))

        return SZ_ERROR_FAIL;

    *pos = (Int64) newpos;

    return SZ_OK;

} /* SZIP_ISeekInStream_Seek */

static void szipInitStream(SZIPLookToRead *stream, PHYSFS_Io *io)

{

    stream->seekStream.Read = SZIP_ISeekInStream_Read;

    stream->seekStream.Seek = SZIP_ISeekInStream_Seek;

    stream->io = io;

    /* !!! FIXME: can we use lookahead? Is there value to it? */

    LookToRead_Init(&stream->lookStream);

    LookToRead_CreateVTable(&stream->lookStream, False);

    stream->lookStream.realStream = &stream->seekStream;

} /* szipInitStream */

/* Do this in a separate function so we can smallAlloc without looping. */

static int szipLoadEntry(SZIPinfo *info, const PHYSFS_uint32 idx)

{

    const size_t utf16len = SzArEx_GetFileNameUtf16(&info->db, idx, NULL);

    const size_t utf16buflen = utf16len * 2;

    PHYSFS_uint16 *utf16 = (PHYSFS_uint16 *) __PHYSFS_smallAlloc(utf16buflen);

    const size_t utf8buflen = utf16len * 4;

    char *utf8 = (char *) __PHYSFS_smallAlloc(utf8buflen);

    int retval = 0;

    if (utf16 && utf8)

    {

        const int isdir = SzArEx_IsDir(&info->db, idx) != 0;

        SZIPentry *entry;

        SzArEx_GetFileNameUtf16(&info->db, idx, (UInt16 *) utf16);

        PHYSFS_utf8FromUtf16(utf16, utf8, utf8buflen);

        entry = (SZIPentry*) __PHYSFS_DirTreeAdd(&info->tree, utf8, isdir);

        retval = (entry != NULL);

        if (retval)

            entry->dbidx = idx;

    } /* if */

    __PHYSFS_smallFree(utf8);

    __PHYSFS_smallFree(utf16);

    return retval;

} /* szipLoadEntry */

static int szipLoadEntries(SZIPinfo *info)

{

    int retval = 0;

    if (__PHYSFS_DirTreeInit(&info->tree, sizeof (SZIPentry)))

    {

        const PHYSFS_uint32 count = info->db.NumFiles;

        PHYSFS_uint32 i;

        for (i = 0; i < count; i++)

            BAIL_IF_ERRPASS(!szipLoadEntry(info, i), 0);

        retval = 1;

    } /* if */

    return retval;

} /* szipLoadEntries */

static void SZIP_closeArchive(void *opaque)

{

    SZIPinfo *info = (SZIPinfo *) opaque;

    if (info)

    {

        if (info->io)

            info->io->destroy(info->io);

        SzArEx_Free(&info->db, &SZIP_SzAlloc);

        __PHYSFS_DirTreeDeinit(&info->tree);

        allocator.Free(info);

    } /* if */

} /* SZIP_closeArchive */

static void *SZIP_openArchive(PHYSFS_Io *io, const char *name,

                              int forWriting, int *claimed)

{

    static const PHYSFS_uint8 wantedsig[] = { '7','z',0xBC,0xAF,0x27,0x1C };

    SZIPLookToRead stream;

    ISzAlloc *alloc = &SZIP_SzAlloc;

    SZIPinfo *info = NULL;

    SRes rc;

    PHYSFS_uint8 sig[6];

    PHYSFS_sint64 pos;

    BAIL_IF(forWriting, PHYSFS_ERR_READ_ONLY, NULL);

    pos = io->tell(io);

    BAIL_IF_ERRPASS(pos == -1, NULL);

    BAIL_IF_ERRPASS(io->read(io, sig, 6) != 6, NULL);

    *claimed = (memcmp(sig, wantedsig, 6) == 0);

    BAIL_IF_ERRPASS(!io->seek(io, pos), NULL);

    info = (SZIPinfo *) allocator.Malloc(sizeof (SZIPinfo));

    BAIL_IF(!info, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

    memset(info, '\0', sizeof (*info));

    SzArEx_Init(&info->db);

    info->io = io;

    szipInitStream(&stream, io);

    rc = SzArEx_Open(&info->db, &stream.lookStream.s, alloc, alloc);

    GOTO_IF(rc != SZ_OK, szipErrorCode(rc), failed);

    GOTO_IF_ERRPASS(!szipLoadEntries(info), failed);

    return info;

failed:

    info->io = NULL;  /* don't let cleanup destroy the PHYSFS_Io. */

    SZIP_closeArchive(info);

    return NULL;

} /* SZIP_openArchive */

static PHYSFS_Io *SZIP_openRead(void *opaque, const char *path)

{

    /* !!! FIXME: the current lzma sdk C API only allows you to decompress

       !!! FIXME:  the entire file at once, which isn't ideal. Fix this in the

       !!! FIXME:  SDK and then convert this all to a streaming interface. */

    SZIPinfo *info = (SZIPinfo *) opaque;

    SZIPentry *entry = (SZIPentry *) __PHYSFS_DirTreeFind(&info->tree, path);

    ISzAlloc *alloc = &SZIP_SzAlloc;

    SZIPLookToRead stream;

    PHYSFS_Io *retval = NULL;

    PHYSFS_Io *io = NULL;

    UInt32 blockIndex = 0xFFFFFFFF;

    Byte *outBuffer = NULL;

    size_t outBufferSize = 0;

    size_t offset = 0;

    size_t outSizeProcessed = 0;

    void *buf = NULL;

    SRes rc;

    BAIL_IF_ERRPASS(!entry, NULL);

    BAIL_IF(entry->tree.isdir, PHYSFS_ERR_NOT_A_FILE, NULL);

    io = info->io->duplicate(info->io);

    GOTO_IF_ERRPASS(!io, SZIP_openRead_failed);

    szipInitStream(&stream, io);

    rc = SzArEx_Extract(&info->db, &stream.lookStream.s, entry->dbidx,

                        &blockIndex, &outBuffer, &outBufferSize, &offset,

                        &outSizeProcessed, alloc, alloc);

    GOTO_IF(rc != SZ_OK, szipErrorCode(rc), SZIP_openRead_failed);

    io->destroy(io);

    io = NULL;

    buf = allocator.Malloc(outSizeProcessed);

    GOTO_IF(rc != SZ_OK, PHYSFS_ERR_OUT_OF_MEMORY, SZIP_openRead_failed);

    memcpy(buf, outBuffer + offset, outSizeProcessed);

    alloc->Free(alloc, outBuffer);

    outBuffer = NULL;

    retval = __PHYSFS_createMemoryIo(buf, outSizeProcessed, allocator.Free);

    GOTO_IF_ERRPASS(!retval, SZIP_openRead_failed);

    return retval;

SZIP_openRead_failed:

    if (io != NULL)

        io->destroy(io);

    if (buf)

        allocator.Free(buf);

    if (outBuffer)

        alloc->Free(alloc, outBuffer);

    return NULL;

} /* SZIP_openRead */

static PHYSFS_Io *SZIP_openWrite(void *opaque, const char *filename)

{

    BAIL(PHYSFS_ERR_READ_ONLY, NULL);

} /* SZIP_openWrite */

static PHYSFS_Io *SZIP_openAppend(void *opaque, const char *filename)

{

    BAIL(PHYSFS_ERR_READ_ONLY, NULL);

} /* SZIP_openAppend */

static int SZIP_remove(void *opaque, const char *name)

{

    BAIL(PHYSFS_ERR_READ_ONLY, 0);

} /* SZIP_remove */

static int SZIP_mkdir(void *opaque, const char *name)

{

    BAIL(PHYSFS_ERR_READ_ONLY, 0);

} /* SZIP_mkdir */

static inline PHYSFS_uint64 lzmasdkTimeToPhysfsTime(const CNtfsFileTime *t)

{

    const PHYSFS_uint64 winEpochToUnixEpoch = __PHYSFS_UI64(0x019DB1DED53E8000);

    const PHYSFS_uint64 nanosecToMillisec = __PHYSFS_UI64(10000000);

    const PHYSFS_uint64 quad = (((PHYSFS_uint64) t->High) << 32) | t->Low;

    return (quad - winEpochToUnixEpoch) / nanosecToMillisec;

} /* lzmasdkTimeToPhysfsTime */

static int SZIP_stat(void *opaque, const char *path, PHYSFS_Stat *stat)

{

    SZIPinfo *info = (SZIPinfo *) opaque;

    SZIPentry *entry;

    PHYSFS_uint32 idx;

    entry = (SZIPentry *) __PHYSFS_DirTreeFind(&info->tree, path);

    BAIL_IF_ERRPASS(!entry, 0);

    idx = entry->dbidx;

    if (entry->tree.isdir)

    {

        stat->filesize = -1;

            stat->filetype = PHYSFS_FILETYPE_DIRECTORY;

    } /* if */

    else

    {

        stat->filesize = (PHYSFS_sint64) SzArEx_GetFileSize(&info->db, idx);

            stat->filetype = PHYSFS_FILETYPE_REGULAR;

    } /* else */

    if (info->db.MTime.Vals != NULL)

            stat->modtime = lzmasdkTimeToPhysfsTime(&info->db.MTime.Vals[idx]);

    else if (info->db.CTime.Vals != NULL)

            stat->modtime = lzmasdkTimeToPhysfsTime(&info->db.CTime.Vals[idx]);

    else

            stat->modtime = -1;

    if (info->db.CTime.Vals != NULL)

            stat->createtime = lzmasdkTimeToPhysfsTime(&info->db.CTime.Vals[idx]);

    else if (info->db.MTime.Vals != NULL)

            stat->createtime = lzmasdkTimeToPhysfsTime(&info->db.MTime.Vals[idx]);

    else

            stat->createtime = -1;

        stat->accesstime = -1;

        stat->readonly = 1;

    return 1;

} /* SZIP_stat */

void SZIP_global_init(void)

{

    /* this just needs to calculate some things, so it only ever

       has to run once, even after a deinit. */

    static int generatedTable = 0;

    if (!generatedTable)

    {

        generatedTable = 1;

        CrcGenerateTable();

    } /* if */

} /* SZIP_global_init */

const PHYSFS_Archiver __PHYSFS_Archiver_7Z =

{

    CURRENT_PHYSFS_ARCHIVER_API_VERSION,

    {

        "7Z",

        "7zip archives",

        "Ryan C. Gordon <icculus@icculus.org>",

        "https://icculus.org/physfs/",

        0,  /* supportsSymlinks */

    },

    SZIP_openArchive,

    __PHYSFS_DirTreeEnumerate,

    SZIP_openRead,

    SZIP_openWrite,

    SZIP_openAppend,

    SZIP_remove,

    SZIP_mkdir,

    SZIP_stat,

    SZIP_closeArchive

};

#endif  /* defined PHYSFS_SUPPORTS_7Z */

/* end of physfs_archiver_7z.c ... */