/*

 * 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 in the source's root directory.

 *

 *  This file written by Ryan C. Gordon.

 */

#if HAVE_CONFIG_H

#  include <config.h>

#endif

#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

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    GRPentry *entries;

} GRPinfo;

typedef struct

{

    void *handle;

    GRPentry *entry;

    PHYSFS_uint32 curPos;

} GRPfileinfo;

static void GRP_dirClose(dvoid *opaque)

{

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

} /* GRP_dirClose */

static PHYSFS_sint64 GRP_read(fvoid *opaque, void *buffer,

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    GRPfileinfo *finfo = (GRPfileinfo *) opaque;

    GRPentry *entry = finfo->entry;

    PHYSFS_uint32 bytesLeft = entry->size - finfo->curPos;

    PHYSFS_uint32 objsLeft = (bytesLeft / objSize);

    PHYSFS_sint64 rc;

    if (objsLeft < objCount)

        objCount = objsLeft;

    rc = __PHYSFS_platformRead(finfo->handle, buffer, objSize, objCount);

    if (rc > 0)

        finfo->curPos += (PHYSFS_uint32) (rc * objSize);

    return(rc);

} /* GRP_read */

static PHYSFS_sint64 GRP_write(fvoid *opaque, const void *buffer,

                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* GRP_write */

static int GRP_eof(fvoid *opaque)

{

    GRPfileinfo *finfo = (GRPfileinfo *) opaque;

    GRPentry *entry = finfo->entry;

    return(finfo->curPos >= entry->size);

} /* GRP_eof */

static PHYSFS_sint64 GRP_tell(fvoid *opaque)

{

    return(((GRPfileinfo *) opaque)->curPos);

} /* GRP_tell */

static int GRP_seek(fvoid *opaque, PHYSFS_uint64 offset)

{

    GRPfileinfo *finfo = (GRPfileinfo *) opaque;

    GRPentry *entry = finfo->entry;

    int rc;

    BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);

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

    rc = __PHYSFS_platformSeek(finfo->handle, entry->startPos + offset);

    if (rc)

        finfo->curPos = (PHYSFS_uint32) offset;

    return(rc);

} /* GRP_seek */

static PHYSFS_sint64 GRP_fileLength(fvoid *opaque)

{

    GRPfileinfo *finfo = (GRPfileinfo *) opaque;

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

} /* GRP_fileLength */

static int GRP_fileClose(fvoid *opaque)

{

    GRPfileinfo *finfo = (GRPfileinfo *) opaque;

    BAIL_IF_MACRO(!__PHYSFS_platformClose(finfo->handle), NULL, 0);

    return(1);

} /* GRP_fileClose */

static int grp_open(const char *filename, int forWriting,

                    void **fh, PHYSFS_uint32 *count)

{

    PHYSFS_uint8 buf[12];

    *fh = NULL;

    BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);

    *fh = __PHYSFS_platformOpenRead(filename);

    BAIL_IF_MACRO(*fh == NULL, NULL, 0);

    if (__PHYSFS_platformRead(*fh, buf, 12, 1) != 1)

        goto openGrp_failed;

    if (memcmp(buf, "KenSilverman", 12) != 0)

    {

        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);

        goto openGrp_failed;

    } /* if */

    if (__PHYSFS_platformRead(*fh, count, sizeof (PHYSFS_uint32), 1) != 1)

        goto openGrp_failed;

    *count = PHYSFS_swapULE32(*count);

    return(1);

openGrp_failed:

    if (*fh != NULL)

        __PHYSFS_platformClose(*fh);

    *count = -1;

    *fh = NULL;

    return(0);

} /* grp_open */

static int GRP_isArchive(const char *filename, int forWriting)

{

    void *fh;

    PHYSFS_uint32 fileCount;

    int retval = grp_open(filename, forWriting, &fh, &fileCount);

    if (fh != NULL)

        __PHYSFS_platformClose(fh);

    return(retval);

} /* GRP_isArchive */

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

{

    GRPentry *a = (GRPentry *) _a;

    return(strcmp(a[one].name, a[two].name));

} /* grp_entry_cmp */

static void grp_entry_swap(void *_a, PHYSFS_uint32 one, PHYSFS_uint32 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));

} /* grp_entry_swap */

static int grp_load_entries(const char *name, int forWriting, GRPinfo *info)

{

    void *fh = NULL;

    PHYSFS_uint32 fileCount;

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

    GRPentry *entry;

    char *ptr;

    BAIL_IF_MACRO(!grp_open(name, forWriting, &fh, &fileCount), NULL, 0);

    info->entryCount = fileCount;

    if (info->entries == NULL)

    {

        __PHYSFS_platformClose(fh);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, 0);

    } /* if */

    location += (16 * fileCount);

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

    {

        if (__PHYSFS_platformRead(fh, &entry->name, 12, 1) != 1)

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

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

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

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

        if (__PHYSFS_platformRead(fh, &entry->size, 4, 1) != 1)

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

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

        entry->startPos = location;

        location += entry->size;

    } /* for */

    __PHYSFS_platformClose(fh);

    __PHYSFS_sort(info->entries, info->entryCount,

                  grp_entry_cmp, grp_entry_swap);

    return(1);

} /* grp_load_entries */

static void *GRP_openArchive(const char *name, int forWriting)

{

    PHYSFS_sint64 modtime = __PHYSFS_platformGetLastModTime(name);

    BAIL_IF_MACRO(info == NULL, ERR_OUT_OF_MEMORY, 0);

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

    GOTO_IF_MACRO(!info->filename, ERR_OUT_OF_MEMORY, GRP_openArchive_failed);

    if (!grp_load_entries(name, forWriting, info))

        goto GRP_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    return(info);

GRP_openArchive_failed:

    if (info != NULL)

    {

        if (info->filename != NULL)

        if (info->entries != NULL)

    } /* if */

    return(NULL);

} /* GRP_openArchive */

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

                               int omitSymLinks, PHYSFS_StringCallback cb,

                               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, entry->name);

    } /* if */

} /* GRP_enumerateFiles */

static GRPentry *grp_find_entry(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);

        rc = strcmp(name, a[middle].name);

        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 */

static PHYSFS_sint64 GRP_getLastModTime(dvoid *opaque,

                                        const char *name,

                                        int *fileExists)

{

    GRPinfo *info = (GRPinfo *) opaque;

    PHYSFS_sint64 retval = -1;

    *fileExists = (grp_find_entry(info, name) != NULL);

    if (*fileExists)  /* use time of GRP itself in the physical filesystem. */

        retval = info->last_mod_time;

    return(retval);

} /* GRP_getLastModTime */

static fvoid *GRP_openRead(dvoid *opaque, const char *fnm, int *fileExists)

{

    GRPinfo *info = (GRPinfo *) opaque;

    GRPfileinfo *finfo;

    GRPentry *entry;

    entry = grp_find_entry(info, fnm);

    *fileExists = (entry != NULL);

    BAIL_IF_MACRO(entry == NULL, NULL, NULL);

    BAIL_IF_MACRO(finfo == NULL, ERR_OUT_OF_MEMORY, NULL);

    finfo->handle = __PHYSFS_platformOpenRead(info->filename);

    if ( (finfo->handle == NULL) ||

         (!__PHYSFS_platformSeek(finfo->handle, entry->startPos)) )

    {

        return(NULL);

    } /* if */

    finfo->curPos = 0;

    finfo->entry = entry;

    return(finfo);

} /* GRP_openRead */

static fvoid *GRP_openWrite(dvoid *opaque, const char *name)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* GRP_openWrite */

static fvoid *GRP_openAppend(dvoid *opaque, const char *name)

{

    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 */

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =

{

    "GRP",

    GRP_ARCHIVE_DESCRIPTION,

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

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

};

const PHYSFS_Archiver __PHYSFS_Archiver_GRP =

{

    &__PHYSFS_ArchiveInfo_GRP,

    GRP_isArchive,          /* isArchive() method      */

    GRP_openArchive,        /* openArchive() method    */

    GRP_enumerateFiles,     /* enumerateFiles() method */

    GRP_exists,             /* exists() method         */

    GRP_isDirectory,        /* isDirectory() method    */

    GRP_isSymLink,          /* isSymLink() method      */

    GRP_getLastModTime,     /* getLastModTime() 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       */

    GRP_read,               /* read() method           */

    GRP_write,              /* write() method          */

    GRP_eof,                /* eof() method            */

    GRP_tell,               /* tell() method           */

    GRP_seek,               /* seek() method           */

    GRP_fileLength,         /* fileLength() method     */

    GRP_fileClose           /* fileClose() method      */

};

#endif  /* defined PHYSFS_SUPPORTS_GRP */

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