/*

 * QPAK support routines for PhysicsFS.

 *

 *  This archiver handles the archive format utilized by Quake 1 and 2.

 *  Quake3-based games use the PkZip/Info-Zip format (which our zip.c

 *  archiver handles).

 *

 *  ========================================================================

 *

 *  This format info (in more detail) comes from:

 *     http://debian.fmi.uni-sofia.bg/~sergei/cgsr/docs/pak.txt

 *

 *  Quake PAK Format

 *

 *  Header

 *   (4 bytes)  signature = 'PACK'

 *   (4 bytes)  directory offset

 *   (4 bytes)  directory length

 *

 *  Directory

 *   (56 bytes) file name

 *   (4 bytes)  file position

 *   (4 bytes)  file length

 *

 *  ========================================================================

 *

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

 *

 *  This file written by Ryan C. Gordon.

 */

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

#if PHYSFS_SUPPORTS_QPAK

#define QPAK_SIG 0x4B434150   /* "PACK" in ASCII. */

static UNPKentry *qpakLoadEntries(PHYSFS_Io *io, PHYSFS_uint32 fileCount)

{

    UNPKentry *entries = NULL;

    UNPKentry *entry = NULL;

    entries = (UNPKentry *) allocator.Malloc(sizeof (UNPKentry) * fileCount);

    BAIL_IF_MACRO(entries == NULL, PHYSFS_ERR_OUT_OF_MEMORY, NULL);

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

    {

        if (!__PHYSFS_readAll(io, &entry->name, 56)) goto failed;

        if (!__PHYSFS_readAll(io, &entry->startPos, 4)) goto failed;

        if (!__PHYSFS_readAll(io, &entry->size, 4)) goto failed;

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

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

    } /* for */

    return entries;

failed:

    allocator.Free(entries);

    return NULL;

} /* qpakLoadEntries */

static void *QPAK_openArchive(PHYSFS_Io *io, const char *name, int forWriting)

{

    UNPKentry *entries = NULL;

    PHYSFS_uint32 val = 0;

    PHYSFS_uint32 pos = 0;

    PHYSFS_uint32 count = 0;

    assert(io != NULL);  /* shouldn't ever happen. */

    BAIL_IF_MACRO(forWriting, PHYSFS_ERR_READ_ONLY, NULL);

    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &val, 4), ERRPASS, NULL);

    if (PHYSFS_swapULE32(val) != QPAK_SIG)

        BAIL_MACRO(PHYSFS_ERR_UNSUPPORTED, NULL);

    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &val, 4), ERRPASS, NULL);

    pos = PHYSFS_swapULE32(val);  /* directory table offset. */

    BAIL_IF_MACRO(!__PHYSFS_readAll(io, &val, 4), ERRPASS, NULL);

    count = PHYSFS_swapULE32(val);

    /* corrupted archive? */

    BAIL_IF_MACRO((count % 64) != 0, PHYSFS_ERR_CORRUPT, NULL);

    count /= 64;

    BAIL_IF_MACRO(!io->seek(io, pos), ERRPASS, NULL);

    entries = qpakLoadEntries(io, count);

    BAIL_IF_MACRO(!entries, ERRPASS, NULL);

    return UNPK_openArchive(io, entries, count);

} /* QPAK_openArchive */

const PHYSFS_Archiver __PHYSFS_Archiver_QPAK =

{

    {

        "PAK",

        "Quake I/II format",

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

    },

};

#endif  /* defined PHYSFS_SUPPORTS_QPAK */