/*

 * HOG support routines for PhysicsFS.

 *

 * This driver handles Descent I/II HOG archives.

 *

 * The format is very simple:

 *

 *   The file always starts with the 3-byte signature "DHF" (Descent

 *   HOG file). After that the files of a HOG are just attached after

 *   another, divided by a 17 bytes header, which specifies the name

 *   and length (in bytes) of the forthcoming file! So you just read

 *   the header with its information of how big the following file is,

 *   and then skip exact that number of bytes to get to the next file

 *   in that HOG.

 *

 *    char sig[3] = {'D', 'H', 'F'}; // "DHF"=Descent HOG File

 *

 *    struct {

 *     char file_name[13]; // Filename, padded to 13 bytes with 0s

 *     int file_size; // filesize in bytes

 *     char data[file_size]; // The file data

 *    } FILE_STRUCT; // Repeated until the end of the file.

 *

 * (That info is from http://www.descent2.com/ddn/specs/hog/)

 *

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

 *

 *  This file written by Bradley Bell.

 *  Based on grp.c by Ryan C. Gordon.

 */

#if (defined PHYSFS_SUPPORTS_HOG)

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "physfs.h"

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

/*

 * One HOGentry is kept for each file in an open HOG archive.

 */

typedef struct

{

    char name[13];

    PHYSFS_uint32 startPos;

    PHYSFS_uint32 size;

} HOGentry;

/*

 * One HOGinfo is kept for each open HOG archive.

 */

typedef struct

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    HOGentry *entries;

} HOGinfo;

/*

 * One HOGfileinfo is kept for each open file in a HOG archive.

 */

typedef struct

{

    void *handle;

    HOGentry *entry;

    PHYSFS_uint32 curPos;

} HOGfileinfo;

static inline int readAll(void *fh, void *buf, const PHYSFS_uint64 len)

{

    return (__PHYSFS_platformRead(fh, buf, len) == len);

} /* readAll */

static void HOG_dirClose(dvoid *opaque)

{

    HOGinfo *info = ((HOGinfo *) opaque);

    allocator.Free(info->filename);

    allocator.Free(info->entries);

    allocator.Free(info);

} /* HOG_dirClose */

static PHYSFS_sint64 HOG_read(fvoid *opaque, void *buffer, PHYSFS_uint64 len)

{

    HOGfileinfo *finfo = (HOGfileinfo *) opaque;

    const HOGentry *entry = finfo->entry;

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

    PHYSFS_sint64 rc;

    if (bytesLeft < len)

        len = bytesLeft;

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

    if (rc > 0)

        finfo->curPos += (PHYSFS_uint32) rc;

    return rc;

} /* HOG_read */

static PHYSFS_sint64 HOG_write(fvoid *f, const void *buf, PHYSFS_uint64 len)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* HOG_write */

static int HOG_eof(fvoid *opaque)

{

    HOGfileinfo *finfo = (HOGfileinfo *) opaque;

    HOGentry *entry = finfo->entry;

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

} /* HOG_eof */

static PHYSFS_sint64 HOG_tell(fvoid *opaque)

{

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

} /* HOG_tell */

static int HOG_seek(fvoid *opaque, PHYSFS_uint64 offset)

{

    HOGfileinfo *finfo = (HOGfileinfo *) opaque;

    HOGentry *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;

} /* HOG_seek */

static PHYSFS_sint64 HOG_fileLength(fvoid *opaque)

{

    HOGfileinfo *finfo = (HOGfileinfo *) opaque;

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

} /* HOG_fileLength */

static int HOG_fileClose(fvoid *opaque)

{

    HOGfileinfo *finfo = (HOGfileinfo *) opaque;

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

    allocator.Free(finfo);

    return 1;

} /* HOG_fileClose */

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

                    void **fh, PHYSFS_uint32 *count)

{

    PHYSFS_uint8 buf[13];

    PHYSFS_uint32 size;

    PHYSFS_sint64 pos;

    *count = 0;

    *fh = NULL;

    BAIL_IF_MACRO(forWriting, ERR_ARC_IS_READ_ONLY, 0);

    *fh = __PHYSFS_platformOpenRead(filename);

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

    if (!readAll(*fh, buf, 3))

        goto openHog_failed;

    if (memcmp(buf, "DHF", 3) != 0)

    {

        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);

        goto openHog_failed;

    } /* if */

    while (1)

    {

        if (!readAll(*fh, buf, 13))

            break; /* eof here is ok */

        if (!readAll(*fh, &size, sizeof (PHYSFS_uint32)))

            goto openHog_failed;

        size = PHYSFS_swapULE32(size);

        (*count)++;

        /* Skip over entry... */

        pos = __PHYSFS_platformTell(*fh);

        if (pos == -1)

            goto openHog_failed;

        if (!__PHYSFS_platformSeek(*fh, pos + size))

            goto openHog_failed;

    } /* while */

    /* Rewind to start of entries... */

    if (!__PHYSFS_platformSeek(*fh, 3))

        goto openHog_failed;

    return 1;

openHog_failed:

    if (*fh != NULL)

        __PHYSFS_platformClose(*fh);

    *count = -1;

    *fh = NULL;

    return 0;

} /* hog_open */

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

{

    void *fh;

    PHYSFS_uint32 fileCount;

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

    if (fh != NULL)

        __PHYSFS_platformClose(fh);

    return retval;

} /* HOG_isArchive */

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

{

    if (one != two)

    {

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

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

    } /* if */

    return 0;

} /* hog_entry_cmp */

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

{

    if (one != two)

    {

        HOGentry tmp;

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

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

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

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

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

    } /* if */

} /* hog_entry_swap */

static int hog_load_entries(const char *name, int forWriting, HOGinfo *info)

{

    void *fh = NULL;

    PHYSFS_uint32 fileCount;

    HOGentry *entry;

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

    info->entryCount = fileCount;

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

    if (info->entries == NULL)

    {

        __PHYSFS_platformClose(fh);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, 0);

    } /* if */

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

    {

        if ( (!readAll(fh, &entry->name, 13)) ||

             (!readAll(fh, &entry->size, sizeof (PHYSFS_uint32))) )

        {

            __PHYSFS_platformClose(fh);

            return 0;

        } /* if */

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

        entry->startPos = (unsigned int) __PHYSFS_platformTell(fh);

        /* Skip over entry */

        if ( (entry->startPos == -1) ||

             (!__PHYSFS_platformSeek(fh, entry->startPos + entry->size)) )

        {

            __PHYSFS_platformClose(fh);

            return 0;

        } /* if */

    } /* for */

    __PHYSFS_platformClose(fh);

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

                  hog_entry_cmp, hog_entry_swap);

    return 1;

} /* hog_load_entries */

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

{

    PHYSFS_sint64 modtime = __PHYSFS_platformGetLastModTime(name);

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

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

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

    info->filename = (char *) allocator.Malloc(strlen(name) + 1);

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

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

        goto HOG_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    return info;

HOG_openArchive_failed:

    if (info != NULL)

    {

        if (info->filename != NULL)

            allocator.Free(info->filename);

        if (info->entries != NULL)

            allocator.Free(info->entries);

        allocator.Free(info);

    } /* if */

    return NULL;

} /* HOG_openArchive */

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

                               int omitSymLinks, PHYSFS_EnumFilesCallback cb,

                               const char *origdir, void *callbackdata)

{

    /* no directories in HOG files. */

    if (*dname == '\0')

    {

        HOGinfo *info = (HOGinfo *) opaque;

        HOGentry *entry = info->entries;

        PHYSFS_uint32 max = info->entryCount;

        PHYSFS_uint32 i;

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

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

    } /* if */

} /* HOG_enumerateFiles */

static HOGentry *hog_find_entry(const HOGinfo *info, const char *name)

{

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

    HOGentry *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 = __PHYSFS_stricmpASCII(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);

} /* hog_find_entry */

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

{

    return (hog_find_entry(((HOGinfo *) opaque), name) != NULL);

} /* HOG_exists */

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

{

    *fileExists = HOG_exists(opaque, name);

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

} /* HOG_isDirectory */

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

{

    *fileExists = HOG_exists(opaque, name);

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

} /* HOG_isSymLink */

static PHYSFS_sint64 HOG_getLastModTime(dvoid *opaque,

                                        const char *name,

                                        int *fileExists)

{

    HOGinfo *info = ((HOGinfo *) opaque);

    PHYSFS_sint64 retval = -1;

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

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

        retval = info->last_mod_time;

    return retval;

} /* HOG_getLastModTime */

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

{

    HOGinfo *info = ((HOGinfo *) opaque);

    HOGfileinfo *finfo;

    HOGentry *entry;

    entry = hog_find_entry(info, fnm);

    *fileExists = (entry != NULL);

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

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

    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)) )

    {

        allocator.Free(finfo);

        return NULL;

    } /* if */

    finfo->curPos = 0;

    finfo->entry = entry;

    return finfo;

} /* HOG_openRead */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* HOG_openWrite */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* HOG_openAppend */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* HOG_remove */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* HOG_mkdir */

static int HOG_stat(fvoid *opaque, const char *filename, int *exists,

                    PHYSFS_Stat *stat)

{

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

    const HOGentry *entry = hog_find_entry(info, filename);

    *exists = (entry != 0);

    if (!entry)

        return 0;

    stat->filesize = entry->size;

    stat->filetype = PHYSFS_FILETYPE_REGULAR;

    stat->modtime = info->last_mod_time;

    stat->createtime = info->last_mod_time;

    stat->accesstime = -1;

    stat->readonly = 1;

} /* HOG_stat */

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_HOG =

{

    "HOG",

    HOG_ARCHIVE_DESCRIPTION,

    "Bradley Bell <btb@icculus.org>",

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

};

const PHYSFS_Archiver __PHYSFS_Archiver_HOG =

{

    &__PHYSFS_ArchiveInfo_HOG,

    HOG_isArchive,          /* isArchive() method      */

    HOG_openArchive,        /* openArchive() method    */

    HOG_enumerateFiles,     /* enumerateFiles() method */