/*

 * 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 <errno.h>

#include <fcntl.h>

#include <assert.h>

#include "physfs.h"

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

typedef struct

{

    char name[13];

    PHYSFS_uint64 startPos;

    PHYSFS_uint64 size;

} GRPentry;

typedef struct

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    GRPentry *entries;

} GRPinfo;

typedef struct

{

    void *handle;

    GRPentry *entry;

    PHYSFS_sint64 curPos;

} GRPfileinfo;

static void GRP_dirClose(DirHandle *h);

static PHYSFS_sint64 GRP_read(FileHandle *handle, void *buffer,

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);

static int GRP_eof(FileHandle *handle);

static PHYSFS_sint64 GRP_tell(FileHandle *handle);

static int GRP_seek(FileHandle *handle, PHYSFS_uint64 offset);

static PHYSFS_sint64 GRP_fileLength(FileHandle *handle);

static int GRP_fileClose(FileHandle *handle);

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

static DirHandle *GRP_openArchive(const char *name, int forWriting);

static LinkedStringList *GRP_enumerateFiles(DirHandle *h,

                                            const char *dirname,

                                            int omitSymLinks);

static int GRP_exists(DirHandle *h, const char *name);

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_GRP =

{

    "GRP",

    GRP_ARCHIVE_DESCRIPTION,

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

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

};

static const FileFunctions __PHYSFS_FileFunctions_GRP =

{

    GRP_read,       /* read() method       */

    GRP_eof,        /* eof() method        */

    GRP_tell,       /* tell() method       */

    GRP_seek,       /* seek() method       */

    GRP_fileLength, /* fileLength() method */

    GRP_fileClose   /* fileClose() method  */

};

const DirFunctions __PHYSFS_DirFunctions_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_dirClose            /* dirClose() method       */

};

static void GRP_dirClose(DirHandle *h)

{

    GRPinfo *info = ((GRPinfo *) h->opaque);

    free(info->filename);

    free(info->entries);

    free(info);

    free(h);

} /* GRP_dirClose */

static PHYSFS_sint64 GRP_read(FileHandle *handle, void *buffer,

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);

    GRPentry *entry = finfo->entry;

    PHYSFS_uint64 bytesLeft = entry->size - finfo->curPos;

    PHYSFS_uint64 objsLeft = (bytesLeft / objSize);

    PHYSFS_sint64 rc;

    if (objsLeft < objCount)

        objCount = (PHYSFS_uint32) objsLeft;

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

    if (rc > 0)

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

    return(rc);

} /* GRP_read */

static int GRP_eof(FileHandle *handle)

{

    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);

    GRPentry *entry = finfo->entry;

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

} /* GRP_eof */

static PHYSFS_sint64 GRP_tell(FileHandle *handle)

{

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

} /* GRP_tell */

static int GRP_seek(FileHandle *handle, PHYSFS_uint64 offset)

{

    GRPfileinfo *finfo = (GRPfileinfo *) (handle->opaque);

    GRPentry *entry = finfo->entry;

    PHYSFS_uint64 newPos = (entry->startPos + offset);

    int rc;

    BAIL_IF_MACRO(offset < 0, ERR_INVALID_ARGUMENT, 0);

    BAIL_IF_MACRO(newPos > entry->startPos + entry->size, ERR_PAST_EOF, 0);

    rc = __PHYSFS_platformSeek(finfo->handle, newPos);

    if (rc)

        finfo->curPos = offset;

    return(rc);

} /* GRP_seek */

static PHYSFS_sint64 GRP_fileLength(FileHandle *handle)

{

    return(((GRPfileinfo *) handle->opaque)->entry->size);

} /* GRP_fileLength */

static int GRP_fileClose(FileHandle *handle)

{

    GRPfileinfo *finfo = ((GRPfileinfo *) handle->opaque);

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

    free(finfo);

    free(handle);

    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;

    info->entries = (GRPentry *) malloc(sizeof (GRPentry) * 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 DirHandle *GRP_openArchive(const char *name, int forWriting)

{

    GRPinfo *info;

    DirHandle *retval = malloc(sizeof (DirHandle));

    PHYSFS_sint64 modtime = __PHYSFS_platformGetLastModTime(name);

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

    info = retval->opaque = malloc(sizeof (GRPinfo));

    if (info == NULL)

    {

        __PHYSFS_setError(ERR_OUT_OF_MEMORY);

        goto GRP_openArchive_failed;

    } /* if */

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

    info->filename = (char *) malloc(strlen(name) + 1);

    if (info->filename == NULL)

    {

        __PHYSFS_setError(ERR_OUT_OF_MEMORY);

        goto GRP_openArchive_failed;

    } /* if */

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

        goto GRP_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    retval->funcs = &__PHYSFS_DirFunctions_GRP;

    return(retval);

GRP_openArchive_failed:

    if (retval != NULL)

    {

        if (retval->opaque != NULL)

        {

            if (info->filename != NULL)

                free(info->filename);

            if (info->entries != NULL)

                free(info->entries);

            free(info);

        } /* if */

        free(retval);

    } /* if */

    return(NULL);

} /* GRP_openArchive */

static LinkedStringList *GRP_enumerateFiles(DirHandle *h,

                                            const char *dirname,

                                            int omitSymLinks)

{

    GRPinfo *info = ((GRPinfo *) h->opaque);

    GRPentry *entry = info->entries;

    LinkedStringList *retval = NULL, *p = NULL;

    PHYSFS_uint32 max = info->entryCount;

    PHYSFS_uint32 i;

    /* no directories in GRP files. */

    BAIL_IF_MACRO(*dirname != '\0', ERR_NOT_A_DIR, NULL);

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

        retval = __PHYSFS_addToLinkedStringList(retval, &p, entry->name, -1);

    return(retval);

} /* 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(DirHandle *h, const char *name)

{

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

} /* GRP_exists */

{

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

} /* GRP_isDirectory */

{

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

} /* GRP_isSymLink */

{

    GRPinfo *info = ((GRPinfo *) h->opaque);

} /* GRP_getLastModTime */

{

    GRPinfo *info = ((GRPinfo *) h->opaque);

    FileHandle *retval;

    GRPfileinfo *finfo;

    GRPentry *entry;

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

    retval = (FileHandle *) malloc(sizeof (FileHandle));

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

    finfo = (GRPfileinfo *) malloc(sizeof (GRPfileinfo));

    if (finfo == NULL)

    {

        free(retval);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, NULL);

    } /* if */

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

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

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