/*

 * WAD support routines for PhysicsFS.

 *

 * This driver handles DOOM engine archives ("wads"). 

 * This format (but not this driver) was designed by id Software for use

 *  with the DOOM engine.

 * The specs of the format are from the unofficial doom specs v1.666

 * found here: http://www.gamers.org/dhs/helpdocs/dmsp1666.html

 * The format of the archive: (from the specs)

 *

 *  A WAD file has three parts:

 *  (1) a twelve-byte header

 *  (2) one or more "lumps"

 *  (3) a directory or "info table" that contains the names, offsets, and

 *      sizes of all the lumps in the WAD

 *

 *  The header consists of three four-byte parts:

 *    (a) an ASCII string which must be either "IWAD" or "PWAD"

 *    (b) a 4-byte (long) integer which is the number of lumps in the wad

 *    (c) a long integer which is the file offset to the start of

 *    the directory

 *

 *  The directory has one 16-byte entry for every lump. Each entry consists

 *  of three parts:

 *

 *    (a) a long integer, the file offset to the start of the lump

 *    (b) a long integer, the size of the lump in bytes

 *    (c) an 8-byte ASCII string, the name of the lump, padded with zeros.

 *        For example, the "DEMO1" entry in hexadecimal would be

 *        (44 45 4D 4F 31 00 00 00)

 * 

 * Note that there is no way to tell if an opened WAD archive is a

 *  IWAD or PWAD with this archiver.

 * I couldn't think of a way to provide that information, without being too

 *  hacky.

 * I don't think it's really that important though.

 *

 *

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

 *

 * This file written by Travis Wells, based on the GRP archiver by

 *  Ryan C. Gordon.

 */

#if HAVE_CONFIG_H

#  include <config.h>

#endif

#if (defined PHYSFS_SUPPORTS_WAD)

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "physfs.h"

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

typedef struct

{

    char name[18];

    PHYSFS_uint32 startPos;

    PHYSFS_uint32 size;

} WADentry;

typedef struct

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    PHYSFS_uint32 entryOffset;

    WADentry *entries;

} WADinfo;

typedef struct

{

    void *handle;

    WADentry *entry;

    PHYSFS_uint32 curPos;

} WADfileinfo;

static void WAD_dirClose(DirHandle *h);

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

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);

static PHYSFS_sint64 WAD_write(FileHandle *handle, const void *buffer,

                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount);

static int WAD_eof(FileHandle *handle);

static PHYSFS_sint64 WAD_tell(FileHandle *handle);

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

static PHYSFS_sint64 WAD_fileLength(FileHandle *handle);

static int WAD_fileClose(FileHandle *handle);

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

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

static LinkedStringList *WAD_enumerateFiles(DirHandle *h,

                                            const char *dirname,

                                            int omitSymLinks);

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

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

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

static PHYSFS_sint64 WAD_getLastModTime(DirHandle *h, const char *n, int *e);

static FileHandle *WAD_openRead(DirHandle *h, const char *name, int *exist);

static FileHandle *WAD_openWrite(DirHandle *h, const char *name);

static FileHandle *WAD_openAppend(DirHandle *h, const char *name);

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

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

const PHYSFS_ArchiveInfo __PHYSFS_ArchiveInfo_WAD =

{

    "WAD",

    /* !!! FIXME WAD_ARCHIVE_DESCRIPTION, */ "DOOM engine format",

    "Travis Wells <traviswells@mchsi.com>",

    "http://www.3dmm2.com/doom/",

};

static const FileFunctions __PHYSFS_FileFunctions_WAD =

{

    WAD_read,       /* read() method       */

    WAD_write,      /* write() method      */

    WAD_eof,        /* eof() method        */

    WAD_tell,       /* tell() method       */

    WAD_seek,       /* seek() method       */

    WAD_fileLength, /* fileLength() method */

    WAD_fileClose   /* fileClose() method  */

};

const DirFunctions __PHYSFS_DirFunctions_WAD =

{

    &__PHYSFS_ArchiveInfo_WAD,

    WAD_isArchive,          /* isArchive() method      */

    WAD_openArchive,        /* openArchive() method    */

    WAD_enumerateFiles,     /* enumerateFiles() method */

    WAD_exists,             /* exists() method         */

    WAD_isDirectory,        /* isDirectory() method    */

    WAD_isSymLink,          /* isSymLink() method      */

    WAD_getLastModTime,     /* getLastModTime() method */

    WAD_openRead,           /* openRead() method       */

    WAD_openWrite,          /* openWrite() method      */

    WAD_openAppend,         /* openAppend() method     */

    WAD_remove,             /* remove() method         */

    WAD_mkdir,              /* mkdir() method          */

    WAD_dirClose            /* dirClose() method       */

};

static void WAD_dirClose(DirHandle *h)

{

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

    free(info->filename);

    free(info->entries);

    free(info);

    free(h);

} /* WAD_dirClose */

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

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

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

    WADentry *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);

} /* WAD_read */

static PHYSFS_sint64 WAD_write(FileHandle *handle, const void *buffer,

                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* WAD_write */

static int WAD_eof(FileHandle *handle)

{

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

    WADentry *entry = finfo->entry;

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

} /* WAD_eof */

static PHYSFS_sint64 WAD_tell(FileHandle *handle)

{

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

} /* WAD_tell */

static int WAD_seek(FileHandle *handle, PHYSFS_uint64 offset)

{

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

    WADentry *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);

} /* WAD_seek */

static PHYSFS_sint64 WAD_fileLength(FileHandle *handle)

{

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

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

} /* WAD_fileLength */

static int WAD_fileClose(FileHandle *handle)

{

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

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

    free(finfo);

    free(handle);

    return(1);

} /* WAD_fileClose */

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

                    void **fh, PHYSFS_uint32 *count,PHYSFS_uint32 *offset)

{

    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 openWad_failed;

    if (memcmp(buf, "IWAD", 4) != 0 && memcmp(buf, "PWAD", 4) != 0)

    {

        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);

        goto openWad_failed;

    } /* if */

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

        goto openWad_failed;

    *count = PHYSFS_swapULE32(*count);

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

        goto openWad_failed;

    *offset = PHYSFS_swapULE32(*offset);

    return(1);

openWad_failed:

    if (*fh != NULL)

        __PHYSFS_platformClose(*fh);

    *count = -1;

    *fh = NULL;

    return(0);

} /* wad_open */

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

{

    void *fh;

    PHYSFS_uint32 fileCount,offset;

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

    if (fh != NULL)

        __PHYSFS_platformClose(fh);

    return(retval);

} /* WAD_isArchive */

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

{

    WADentry *a = (WADentry *) _a;

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

} /* wad_entry_cmp */

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

{

    WADentry tmp;

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

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

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

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

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

} /* wad_entry_swap */

static int wad_load_entries(const char *name, int forWriting, WADinfo *info)

{

    void *fh = NULL;

    PHYSFS_uint32 fileCount;

    PHYSFS_uint32 directoryOffset;

    WADentry *entry;

    char lastDirectory[9];

    lastDirectory[8] = 0; /* Make sure lastDirectory stays null-terminated. */

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

    info->entryCount = fileCount;

    info->entries = (WADentry *) malloc(sizeof (WADentry) * fileCount);

    if (info->entries == NULL)

    {

        __PHYSFS_platformClose(fh);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, 0);

    } /* if */

    __PHYSFS_platformSeek(fh,directoryOffset);

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

    {

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

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

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

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

        if (__PHYSFS_platformRead(fh, &entry->name, 8, 1) != 1)

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

        entry->name[8] = '\0'; /* name might not be null-terminated in file. */

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

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

    } /* for */

    __PHYSFS_platformClose(fh);

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

                  wad_entry_cmp, wad_entry_swap);

    return(1);

} /* wad_load_entries */

static DirHandle *WAD_openArchive(const char *name, int forWriting)

{

    WADinfo *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 (WADinfo));

    if (info == NULL)

    {

        __PHYSFS_setError(ERR_OUT_OF_MEMORY);

        goto WAD_openArchive_failed;

    } /* if */

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

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

    if (info->filename == NULL)

    {

        __PHYSFS_setError(ERR_OUT_OF_MEMORY);

        goto WAD_openArchive_failed;

    } /* if */

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

        goto WAD_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    retval->funcs = &__PHYSFS_DirFunctions_WAD;

    return(retval);

WAD_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);

} /* WAD_openArchive */

static LinkedStringList *WAD_enumerateFiles(DirHandle *h,

                                            const char *dirname,

                                            int omitSymLinks)

{

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

    WADentry *entry = info->entries;

    LinkedStringList *retval = NULL, *p = NULL;

    PHYSFS_uint32 max = info->entryCount;

    PHYSFS_uint32 i;

    char *sep;

    if (dirname[0] == 0)

    {

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

        {

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

            {

                retval = __PHYSFS_addToLinkedStringList(retval, &p,

                                                        entry->name, -1);

            } /* if */

        } /* for */

    } /* if */

    else

    {

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

        {

            sep = strchr(entry->name, '/');

            if (sep != NULL)

            {

                if (strncmp(dirname, entry->name, (sep-entry->name)) == 0)

                {

                    retval = __PHYSFS_addToLinkedStringList(retval, &p,

                                                            sep + 1, -1);

                } /* if */

            } /* if */

        } /* for */

    } /* else */

    return(retval);

} /* WAD_enumerateFiles */

static WADentry *wad_find_entry(WADinfo *info, const char *name)

{

    WADentry *a = info->entries;

    PHYSFS_sint32 lo = 0;

    PHYSFS_sint32 hi = (PHYSFS_sint32) (info->entryCount - 1);

    PHYSFS_sint32 middle;

    int rc;

    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);

} /* wad_find_entry */

static int WAD_exists(DirHandle *h, const char *name)

{

    return(wad_find_entry(((WADinfo *) h->opaque), name) != NULL);

} /* WAD_exists */

static int WAD_isDirectory(DirHandle *h, const char *name, int *fileExists)

{

    WADentry *entry = wad_find_entry(((WADinfo *) h->opaque), name);

    if (entry != NULL)

    {

        char *n;

        *fileExists = 1;

        /* Can't be a directory if it's a subdirectory. */

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

            return(0);

        /* Check if it matches "MAP??" or "E?M?" ... */

        n = entry->name;

        if ((n[0] == 'E' && n[2] == 'M') ||

            (n[0] == 'M' && n[1] == 'A' && n[2] == 'P' && n[6] == 0))

        {

            return(1);

        } /* if */

        return(0);

    } /* if */

    else

    {

        *fileExists = 0;

        return(0);

    } /* else */

} /* WAD_isDirectory */

static int WAD_isSymLink(DirHandle *h, const char *name, int *fileExists)

{

    *fileExists = WAD_exists(h, name);

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

} /* WAD_isSymLink */

static PHYSFS_sint64 WAD_getLastModTime(DirHandle *h,

                                        const char *name,

                                        int *fileExists)

{

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

    PHYSFS_sint64 retval = -1;