/*

 * MVL support routines for PhysicsFS.

 *

 * This driver handles Descent II Movielib archives.

 *

 * The file format of MVL is quite easy...

 *

 *   //MVL File format - Written by Heiko Herrmann

 *   char sig[4] = {'D','M', 'V', 'L'}; // "DMVL"=Descent MoVie Library

 *

 *   int num_files; // the number of files in this MVL

 *

 *   struct {

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

 *    int file_size; // filesize in bytes

 *   }DIR_STRUCT[num_files];

 *

 *   struct {

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

 *   }FILE_STRUCT[num_files];

 *

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

 *

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

 *

 *  This file written by Bradley Bell.

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

 */

#if HAVE_CONFIG_H

#  include <config.h>

#endif

#if (defined PHYSFS_SUPPORTS_MVL)

#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;

} MVLentry;

typedef struct

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    MVLentry *entries;

} MVLinfo;

typedef struct

{

    void *handle;

    MVLentry *entry;

    PHYSFS_uint32 curPos;

} MVLfileinfo;

static void MVL_dirClose(dvoid *opaque)

{

    MVLinfo *info = ((MVLinfo *) opaque);

    allocator.Free(info->filename);

    allocator.Free(info->entries);

    allocator.Free(info);

} /* MVL_dirClose */

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

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    MVLfileinfo *finfo = (MVLfileinfo *) opaque;

    MVLentry *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);

} /* MVL_read */

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

                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* MVL_write */

static int MVL_eof(fvoid *opaque)

{

    MVLfileinfo *finfo = (MVLfileinfo *) opaque;

    MVLentry *entry = finfo->entry;

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

} /* MVL_eof */

static PHYSFS_sint64 MVL_tell(fvoid *opaque)

{

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

} /* MVL_tell */

static int MVL_seek(fvoid *opaque, PHYSFS_uint64 offset)

{

    MVLfileinfo *finfo = (MVLfileinfo *) opaque;

    MVLentry *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);

} /* MVL_seek */

static PHYSFS_sint64 MVL_fileLength(fvoid *opaque)

{

    MVLfileinfo *finfo = (MVLfileinfo *) opaque;

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

} /* MVL_fileLength */

static int MVL_fileClose(fvoid *opaque)

{

    MVLfileinfo *finfo = (MVLfileinfo *) opaque;

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

    allocator.Free(finfo);

    return(1);

} /* MVL_fileClose */

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

                    void **fh, PHYSFS_uint32 *count)

{

    PHYSFS_uint8 buf[4];

    *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, 4, 1) != 1)

        goto openMvl_failed;

    if (memcmp(buf, "DMVL", 4) != 0)

    {

        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);

        goto openMvl_failed;

    } /* if */

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

        goto openMvl_failed;

    *count = PHYSFS_swapULE32(*count);

    return(1);

openMvl_failed:

    if (*fh != NULL)

        __PHYSFS_platformClose(*fh);

    *count = -1;

    *fh = NULL;

    return(0);

} /* mvl_open */

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

{

    void *fh;

    PHYSFS_uint32 fileCount;

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

    if (fh != NULL)

        __PHYSFS_platformClose(fh);

    return(retval);

} /* MVL_isArchive */

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

{

    MVLentry *a = (MVLentry *) _a;

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

} /* mvl_entry_cmp */

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

{

    MVLentry tmp;

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

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

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

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

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

} /* mvl_entry_swap */

static int mvl_load_entries(const char *name, int forWriting, MVLinfo *info)

{

    void *fh = NULL;

    PHYSFS_uint32 fileCount;

    PHYSFS_uint32 location = 8;  /* sizeof sig. */

    MVLentry *entry;

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

    info->entryCount = fileCount;

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

    if (info->entries == NULL)

    {

        __PHYSFS_platformClose(fh);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, 0);

    } /* if */

    location += (17 * fileCount);

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

    {

        if (__PHYSFS_platformRead(fh, &entry->name, 13, 1) != 1)

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

        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,

                  mvl_entry_cmp, mvl_entry_swap);

    return(1);

} /* mvl_load_entries */

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

{

    PHYSFS_sint64 modtime = __PHYSFS_platformGetLastModTime(name);

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

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

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

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

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

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

        goto MVL_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    return(info);

MVL_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);

} /* MVL_openArchive */

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

                               int omitSymLinks, PHYSFS_StringCallback cb,

                               void *callbackdata)

{

    /* no directories in MVL files. */

    if (*dname != '\0')

    {

        MVLinfo *info = ((MVLinfo *) opaque);

        MVLentry *entry = info->entries;

        PHYSFS_uint32 max = info->entryCount;

        PHYSFS_uint32 i;

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

            cb(callbackdata, entry->name);

    } /* if */

} /* MVL_enumerateFiles */

static MVLentry *mvl_find_entry(MVLinfo *info, const char *name)

{

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

    MVLentry *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_platformStricmp(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);

} /* mvl_find_entry */

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

{

    return(mvl_find_entry(((MVLinfo *) opaque), name) != NULL);

} /* MVL_exists */

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

{

    *fileExists = MVL_exists(opaque, name);

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

} /* MVL_isDirectory */

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

{

    *fileExists = MVL_exists(opaque, name);

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

} /* MVL_isSymLink */

static PHYSFS_sint64 MVL_getLastModTime(dvoid *opaque,

                                        const char *name,

                                        int *fileExists)

{

    MVLinfo *info = ((MVLinfo *) opaque);

    PHYSFS_sint64 retval = -1;

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

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

        retval = info->last_mod_time;

    return(retval);

} /* MVL_getLastModTime */

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

{

    MVLinfo *info = ((MVLinfo *) opaque);

    MVLfileinfo *finfo;

    MVLentry *entry;

    entry = mvl_find_entry(info, fnm);

    *fileExists = (entry != NULL);

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

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

    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);

} /* MVL_openRead */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* MVL_openWrite */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, NULL);

} /* MVL_openAppend */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* MVL_remove */

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

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, 0);

} /* MVL_mkdir */

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_MVL =

{

    "MVL",

    MVL_ARCHIVE_DESCRIPTION,

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

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

};

const PHYSFS_Archiver __PHYSFS_Archiver_MVL =

{

    &__PHYSFS_ArchiveInfo_MVL,

    MVL_isArchive,          /* isArchive() method      */

    MVL_openArchive,        /* openArchive() method    */

    MVL_enumerateFiles,     /* enumerateFiles() method */

    MVL_exists,             /* exists() method         */

    MVL_isDirectory,        /* isDirectory() method    */

    MVL_isSymLink,          /* isSymLink() method      */

    MVL_getLastModTime,     /* getLastModTime() method */

    MVL_openRead,           /* openRead() method       */

    MVL_openWrite,          /* openWrite() method      */

    MVL_openAppend,         /* openAppend() method     */

    MVL_remove,             /* remove() method         */

    MVL_mkdir,              /* mkdir() method          */

    MVL_dirClose,           /* dirClose() method       */

    MVL_read,               /* read() method           */

    MVL_write,              /* write() method          */

    MVL_eof,                /* eof() method            */

    MVL_tell,               /* tell() method           */

    MVL_seek,               /* seek() method           */

    MVL_fileLength,         /* fileLength() method     */

    MVL_fileClose           /* fileClose() method      */

};

#endif  /* defined PHYSFS_SUPPORTS_MVL */

/* end of mvl.c ... */