/*

 * 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 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_QPAK)

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "physfs.h"

#define __PHYSICSFS_INTERNAL__

#include "physfs_internal.h"

#if 1  /* Make this case insensitive? */

#define QPAK_strcmp(x, y) __PHYSFS_platformStricmp(x, y)

#define QPAK_strncmp(x, y, z) __PHYSFS_platformStrnicmp(x, y, z)

#else

#define QPAK_strcmp(x, y) strcmp(x, y)

#define QPAK_strncmp(x, y, z) strncmp(x, y, z)

#endif

typedef struct

{

    char name[56];

    PHYSFS_uint32 startPos;

    PHYSFS_uint32 size;

} QPAKentry;

typedef struct

{

    char *filename;

    PHYSFS_sint64 last_mod_time;

    PHYSFS_uint32 entryCount;

    QPAKentry *entries;

} QPAKinfo;

typedef struct

{

    void *handle;

    QPAKentry *entry;

    PHYSFS_uint32 curPos;

} QPAKfileinfo;

/* Magic numbers... */

#define QPAK_SIGNATURE 0x4b434150   /* "PACK" in ASCII. */

static void QPAK_dirClose(dvoid *opaque)

{

    QPAKinfo *info = ((QPAKinfo *) opaque);

    free(info->filename);

    free(info->entries);

    free(info);

} /* QPAK_dirClose */

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

                              PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) opaque;

    QPAKentry *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);

} /* QPAK_read */

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

                               PHYSFS_uint32 objSize, PHYSFS_uint32 objCount)

{

    BAIL_MACRO(ERR_NOT_SUPPORTED, -1);

} /* QPAK_write */

static int QPAK_eof(fvoid *opaque)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) opaque;

    QPAKentry *entry = finfo->entry;

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

} /* QPAK_eof */

static PHYSFS_sint64 QPAK_tell(fvoid *opaque)

{

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

} /* QPAK_tell */

static int QPAK_seek(fvoid *opaque, PHYSFS_uint64 offset)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) opaque;

    QPAKentry *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);

} /* QPAK_seek */

static PHYSFS_sint64 QPAK_fileLength(fvoid *opaque)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) opaque;

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

} /* QPAK_fileLength */

static int QPAK_fileClose(fvoid *opaque)

{

    QPAKfileinfo *finfo = (QPAKfileinfo *) opaque;

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

    free(finfo);

    return(1);

} /* QPAK_fileClose */

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

                    void **fh, PHYSFS_uint32 *count)

{

    PHYSFS_uint32 buf;

    *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, sizeof (PHYSFS_uint32), 1) != 1)

        goto openQpak_failed;

    buf = PHYSFS_swapULE32(buf);

    if (buf != QPAK_SIGNATURE)

    {

        __PHYSFS_setError(ERR_UNSUPPORTED_ARCHIVE);

        goto openQpak_failed;

    } /* if */

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

        goto openQpak_failed;

    buf = PHYSFS_swapULE32(buf);  /* directory table offset. */

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

        goto openQpak_failed;

    *count = PHYSFS_swapULE32(*count);

    if ((*count % 64) != 0)  /* corrupted archive? */

    {

        __PHYSFS_setError(ERR_CORRUPTED);

        goto openQpak_failed;

    } /* if */

    if (!__PHYSFS_platformSeek(*fh, buf))

        goto openQpak_failed;

    *count /= 64;

    return(1);

openQpak_failed:

    if (*fh != NULL)

        __PHYSFS_platformClose(*fh);

    *count = -1;

    *fh = NULL;

    return(0);

} /* qpak_open */

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

{

    void *fh;

    PHYSFS_uint32 fileCount;

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

    if (fh != NULL)

        __PHYSFS_platformClose(fh);

    return(retval);

} /* QPAK_isArchive */

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

{

    QPAKentry *a = (QPAKentry *) _a;

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

} /* qpak_entry_cmp */

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

{

    QPAKentry tmp;

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

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

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

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

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

} /* qpak_entry_swap */

static int qpak_load_entries(const char *name, int forWriting, QPAKinfo *info)

{

    void *fh = NULL;

    PHYSFS_uint32 fileCount;

    QPAKentry *entry;

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

    info->entryCount = fileCount;

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

    if (info->entries == NULL)

    {

        __PHYSFS_platformClose(fh);

        BAIL_MACRO(ERR_OUT_OF_MEMORY, 0);

    } /* if */

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

    {

        PHYSFS_uint32 loc;

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

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

        if (__PHYSFS_platformRead(fh,&loc,sizeof(loc),1) != 1)

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

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

        {

            __PHYSFS_platformClose(fh);

            return(0);

        } /* if */

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

        entry->startPos = PHYSFS_swapULE32(loc);

    } /* for */

    __PHYSFS_platformClose(fh);

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

                  qpak_entry_cmp, qpak_entry_swap);

    return(1);

} /* qpak_load_entries */

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

{

    QPAKinfo *info = malloc(sizeof (QPAKinfo));

    PHYSFS_sint64 modtime = __PHYSFS_platformGetLastModTime(name);

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

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

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

    if (info->filename == NULL)

    {

        __PHYSFS_setError(ERR_OUT_OF_MEMORY);

        goto QPAK_openArchive_failed;

    } /* if */

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

        goto QPAK_openArchive_failed;

    strcpy(info->filename, name);

    info->last_mod_time = modtime;

    return(info);

QPAK_openArchive_failed:

    if (info != NULL)

    {

        if (info->filename != NULL)

            free(info->filename);

        if (info->entries != NULL)

            free(info->entries);

        free(info);

    } /* if */

    return(NULL);

} /* QPAK_openArchive */

static PHYSFS_sint32 qpak_find_start_of_dir(QPAKinfo *info, const char *path,

                                            int stop_on_first_find)

{

    PHYSFS_sint32 lo = 0;

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

    PHYSFS_sint32 middle;

    PHYSFS_uint32 dlen = strlen(path);

    PHYSFS_sint32 retval = -1;

    const char *name;

    int rc;

    if (*path == '\0')  /* root dir? */

        return(0);

    if ((dlen > 0) && (path[dlen - 1] == '/')) /* ignore trailing slash. */

        dlen--;

    while (lo <= hi)

    {

        middle = lo + ((hi - lo) / 2);

        name = info->entries[middle].name;

        rc = QPAK_strncmp(path, name, dlen);

        if (rc == 0)

        {

            char ch = name[dlen];

            if (ch < '/') /* make sure this isn't just a substr match. */

                rc = -1;

            else if (ch > '/')

                rc = 1;

            else 

            {

                if (stop_on_first_find) /* Just checking dir's existance? */

                    return(middle);

                if (name[dlen + 1] == '\0') /* Skip initial dir entry. */

                    return(middle + 1);

                /* there might be more entries earlier in the list. */

                retval = middle;

                hi = middle - 1;

            } /* else */

        } /* if */

        if (rc > 0)

            lo = middle + 1;

        else

            hi = middle - 1;

    } /* while */

    return(retval);

} /* qpak_find_start_of_dir */

/*

 * Moved to seperate function so we can use alloca then immediately throw

 *  away the allocated stack space...

 */

static void doEnumCallback(PHYSFS_StringCallback cb, void *callbackdata,

                           const char *str, PHYSFS_sint32 ln)

{

    char *newstr = alloca(ln + 1);

    if (newstr == NULL)

        return;

    memcpy(newstr, str, ln);

    newstr[ln] = '\0';

    cb(callbackdata, newstr);

} /* doEnumCallback */

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

                                int omitSymLinks, PHYSFS_StringCallback cb,

                                void *callbackdata)

{

    QPAKinfo *info = ((QPAKinfo *) opaque);

    PHYSFS_sint32 dlen, dlen_inc, max, i;

    i = qpak_find_start_of_dir(info, dname, 0);

    if (i == -1)  /* no such directory. */

        return;

    dlen = strlen(dname);

    if ((dlen > 0) && (dname[dlen - 1] == '/')) /* ignore trailing slash. */

        dlen--;

    dlen_inc = ((dlen > 0) ? 1 : 0) + dlen;

    max = (PHYSFS_sint32) info->entryCount;

    while (i < max)

    {

        char *add;

        char *ptr;

        PHYSFS_sint32 ln;

        char *e = info->entries[i].name;

        if ((dlen) && ((QPAK_strncmp(e, dname, dlen)) || (e[dlen] != '/')))

            break;  /* past end of this dir; we're done. */

        add = e + dlen_inc;

        ptr = strchr(add, '/');

        ln = (PHYSFS_sint32) ((ptr) ? ptr-add : strlen(add));

        doEnumCallback(cb, callbackdata, add, ln);

        ln += dlen_inc;  /* point past entry to children... */

        /* increment counter and skip children of subdirs... */

        while ((++i < max) && (ptr != NULL))

        {

            char *e_new = info->entries[i].name;

            if ((QPAK_strncmp(e, e_new, ln) != 0) || (e_new[ln] != '/'))

                break;

        } /* while */

    } /* while */

} /* QPAK_enumerateFiles */

/*

 * This will find the QPAKentry associated with a path in platform-independent

 *  notation. Directories don't have QPAKentries associated with them, but 

 *  (*isDir) will be set to non-zero if a dir was hit.

 */

static QPAKentry *qpak_find_entry(QPAKinfo *info, const char *path, int *isDir)

{

    QPAKentry *a = info->entries;

    PHYSFS_sint32 pathlen = strlen(path);

    PHYSFS_sint32 lo = 0;

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

    PHYSFS_sint32 middle;

    const char *thispath = NULL;

    int rc;

    while (lo <= hi)

    {

        middle = lo + ((hi - lo) / 2);

        thispath = a[middle].name;

        rc = QPAK_strncmp(path, thispath, pathlen);

        if (rc > 0)

            lo = middle + 1;

        else if (rc < 0)

            hi = middle - 1;

        else /* substring match...might be dir or entry or nothing. */

        {

            if (isDir != NULL)

            {

                *isDir = (thispath[pathlen] == '/');

                if (*isDir)

                    return(NULL);

            } /* if */

            if (thispath[pathlen] == '\0') /* found entry? */

                return(&a[middle]);

            else

                hi = middle - 1;  /* adjust search params, try again. */

        } /* if */

    } /* while */

    if (isDir != NULL)

        *isDir = 0;

    BAIL_MACRO(ERR_NO_SUCH_FILE, NULL);

} /* qpak_find_entry */

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

{

    int isDir;    

    QPAKinfo *info = (QPAKinfo *) opaque;

    QPAKentry *entry = qpak_find_entry(info, name, &isDir);

    return((entry != NULL) || (isDir));

} /* QPAK_exists */

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

{

    QPAKinfo *info = (QPAKinfo *) opaque;

    int isDir;

    QPAKentry *entry = qpak_find_entry(info, name, &isDir);

    *fileExists = ((isDir) || (entry != NULL));

    if (isDir)

        return(1); /* definitely a dir. */

    BAIL_MACRO(ERR_NO_SUCH_FILE, 0);

} /* QPAK_isDirectory */

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

{