/*

 * GRP support routines for PhysicsFS.

 *

 * This driver handles BUILD engine archives ("groupfiles"). This format

 *  (but not this driver) was put together by Ken Silverman.

 *

 * The format is simple enough. In Ken's words:

 *

 *    What's the .GRP file format?

 *

 *     The ".grp" file format is just a collection of a lot of files stored

 *     into 1 big one. I tried to make the format as simple as possible: The

 *     first 12 bytes contains my name, "KenSilverman". The next 4 bytes is

 *     the number of files that were compacted into the group file. Then for

 *     each file, there is a 16 byte structure, where the first 12 bytes are

 *     the filename, and the last 4 bytes are the file's size. The rest of

 *     the group file is just the raw data packed one after the other in the

 *     same order as the list of files.

 *

 * (That info is from http://www.advsys.net/ken/build.htm ...)

 *

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

 *

 *  This file written by Ryan C. Gordon.

 */

#if (defined PHYSFS_SUPPORTS_GRP)

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "physfs.h"

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

typedef struct

{

    char name[13];

    PHYSFS_uint32 startPos;

    PHYSFS_uint32 size;

} GRPentry;

typedef struct

{

    PHYSFS_uint32 entryCount;

    GRPentry *entries;

} GRPinfo;

typedef struct

{

    GRPentry *entry;

    PHYSFS_uint32 curPos;

} GRPfileinfo;

{

} /* readAll */

static void GRP_dirClose(dvoid *opaque)

{

    GRPinfo *info = ((GRPinfo *) opaque);

    allocator.Free(info->entries);

    allocator.Free(info);

} /* GRP_dirClose */

{

    const GRPentry *entry = finfo->entry;

    const PHYSFS_uint64 bytesLeft = (PHYSFS_uint64)(entry->size-finfo->curPos);

    PHYSFS_sint64 rc;

    if (bytesLeft < len)

        len = bytesLeft;

    if (rc > 0)

        finfo->curPos += (PHYSFS_uint32) rc;

    return rc;

} /* GRP_read */

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* GRP_write */

{

} /* GRP_tell */

{

    int rc;

    BAIL_IF_MACRO(offset >= entry->size, ERR_PAST_EOF, 0);

    if (rc)

        finfo->curPos = (PHYSFS_uint32) offset;

    return rc;

} /* GRP_seek */

{

    return ((PHYSFS_sint64) finfo->entry->size);

{

{

    if (one != two)

    {

        const GRPentry *a = (const GRPentry *) _a;

    } /* if */

    return 0;

{

    if (one != two)

    {

        GRPentry tmp;

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

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

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

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

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

    } /* if */

{

    PHYSFS_uint32 location = 16;  /* sizeof sig. */

    GRPentry *entry;

    char *ptr;

    info->entries = (GRPentry *) allocator.Malloc(sizeof(GRPentry)*fileCount);

    location += (16 * fileCount);

    for (entry = info->entries; fileCount > 0; fileCount--, entry++)

    {

        entry->name[12] = '\0';  /* name isn't null-terminated in file. */

        if ((ptr = strchr(entry->name, ' ')) != NULL)

            *ptr = '\0';  /* trim extra spaces. */

        entry->size = PHYSFS_swapULE32(entry->size);

        entry->startPos = location;

        location += entry->size;

    } /* for */

    return 1;

} /* grp_load_entries */

{

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

    return info;

GRP_openArchive_failed:

    if (info != NULL)

    {

        if (info->entries != NULL)

            allocator.Free(info->entries);

        allocator.Free(info);

    } /* if */

    return NULL;

} /* GRP_openArchive */

static void GRP_enumerateFiles(dvoid *opaque, const char *dname,

                               int omitSymLinks, PHYSFS_EnumFilesCallback cb,

                               const char *origdir, void *callbackdata)

{

    /* no directories in GRP files. */

    if (*dname == '\0')

    {

        GRPinfo *info = (GRPinfo *) opaque;

        GRPentry *entry = info->entries;

        PHYSFS_uint32 max = info->entryCount;

        PHYSFS_uint32 i;

        for (i = 0; i < max; i++, entry++)

            cb(callbackdata, origdir, entry->name);

    } /* if */

} /* GRP_enumerateFiles */

static GRPentry *grp_find_entry(const GRPinfo *info, const char *name)

{

    char *ptr = strchr(name, '.');

    GRPentry *a = info->entries;

    PHYSFS_sint32 lo = 0;

    PHYSFS_sint32 hi = (PHYSFS_sint32) (info->entryCount - 1);

    PHYSFS_sint32 middle;

    int rc;

    /*

     * Rule out filenames to avoid unneeded processing...no dirs,

     *   big filenames, or extensions > 3 chars.

     */

    BAIL_IF_MACRO((ptr) && (strlen(ptr) > 4), ERR_NO_SUCH_FILE, NULL);

    BAIL_IF_MACRO(strlen(name) > 12, ERR_NO_SUCH_FILE, NULL);

    BAIL_IF_MACRO(strchr(name, '/') != NULL, ERR_NO_SUCH_FILE, NULL);

    while (lo <= hi)

    {

        middle = lo + ((hi - lo) / 2);

        if (rc == 0)  /* found it! */

            return &a[middle];

        else if (rc > 0)

            lo = middle + 1;

        else

            hi = middle - 1;

    } /* while */

    BAIL_MACRO(ERR_NO_SUCH_FILE, NULL);

} /* grp_find_entry */

static int GRP_exists(dvoid *opaque, const char *name)

{

    return (grp_find_entry((GRPinfo *) opaque, name) != NULL);

} /* GRP_exists */

static int GRP_isDirectory(dvoid *opaque, const char *name, int *fileExists)

{

    *fileExists = GRP_exists(opaque, name);

    return 0;  /* never directories in a groupfile. */

} /* GRP_isDirectory */

static int GRP_isSymLink(dvoid *opaque, const char *name, int *fileExists)

{

    *fileExists = GRP_exists(opaque, name);

    return 0;  /* never symlinks in a groupfile. */

} /* GRP_isSymLink */

{

    GRPinfo *info = (GRPinfo *) opaque;

    GRPfileinfo *finfo;

    GRPentry *entry;

    entry = grp_find_entry(info, fnm);

    *fileExists = (entry != NULL);

    finfo = (GRPfileinfo *) allocator.Malloc(sizeof (GRPfileinfo));

    finfo->curPos = 0;

    finfo->entry = entry;

} /* GRP_openRead */

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* GRP_openWrite */

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* GRP_openAppend */

static int GRP_remove(dvoid *opaque, const char *name)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* GRP_remove */

static int GRP_mkdir(dvoid *opaque, const char *name)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* GRP_mkdir */

static int GRP_stat(dvoid *opaque, const char *filename, int *exists,

                    PHYSFS_Stat *stat)

{

    const GRPinfo *info = (const GRPinfo *) opaque;

    const GRPentry *entry = grp_find_entry(info, filename);

    *exists = (entry != 0);

    if (!entry)

        return 0;

    stat->filesize = entry->size;

    stat->filetype = PHYSFS_FILETYPE_REGULAR;

    stat->modtime = -1;

    stat->createtime = -1;

    stat->accesstime = -1;

    stat->readonly = 1;

    return 1;

} /* GRP_stat */

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =

{

    "GRP",

    GRP_ARCHIVE_DESCRIPTION,

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

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

};

const PHYSFS_Archiver __PHYSFS_Archiver_GRP =

{

    &__PHYSFS_ArchiveInfo_GRP,

    GRP_openArchive,        /* openArchive() method    */

    GRP_enumerateFiles,     /* enumerateFiles() method */

    GRP_exists,             /* exists() method         */

    GRP_isDirectory,        /* isDirectory() method    */

    GRP_isSymLink,          /* isSymLink() method      */

    GRP_openRead,           /* openRead() method       */

    GRP_openWrite,          /* openWrite() method      */

    GRP_openAppend,         /* openAppend() method     */

    GRP_remove,             /* remove() method         */

    GRP_mkdir,              /* mkdir() method          */

    GRP_dirClose,           /* dirClose() method       */

};

#endif  /* defined PHYSFS_SUPPORTS_GRP */

/* end of grp.c ... */