/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

/* This file provides a general interface for SDL to read and write

   data sources.  It can easily be extended to files, memory, etc.

*/

#include "SDL_endian.h"

#include "SDL_rwops.h"

#ifdef __APPLE__

#include "cocoa/SDL_rwopsbundlesupport.h"

#endif /* __APPLE__ */

#ifdef __NDS__

/* include libfat headers for fatInitDefault(). */

#include <fat.h>

#endif /* __NDS__ */

/* Functions to read/write Win32 API file pointers */

/* Will not use it on WinCE because stdio is buffered, it means

   faster, and all stdio functions anyway are embedded in coredll.dll - 

   the main wince dll*/

#define WINDOWS_LEAN_AND_MEAN

#include <windows.h>

#ifndef INVALID_SET_FILE_POINTER

#define INVALID_SET_FILE_POINTER 0xFFFFFFFF

#endif

#define READAHEAD_BUFFER_SIZE	1024

static int SDLCALL

{

#ifndef _WIN32_WCE

    UINT old_error_mode;

#endif

    HANDLE h;

    DWORD r_right, w_right;

    DWORD must_exist, truncate;

    int a_mode;

    if (!context)

        return -1;              /* failed (invalid call) */

    /* "r" = reading, file must exist */

    /* "w" = writing, truncate existing, file may not exist */

    /* "r+"= reading or writing, file must exist            */

    /* "a" = writing, append file may not exist             */

    /* "a+"= append + read, file may not exist              */

    /* "w+" = read, write, truncate. file may not exist    */

    must_exist = (SDL_strchr(mode, 'r') != NULL) ? OPEN_EXISTING : 0;

    truncate = (SDL_strchr(mode, 'w') != NULL) ? CREATE_ALWAYS : 0;

    r_right = (SDL_strchr(mode, '+') != NULL

               || must_exist) ? GENERIC_READ : 0;

    a_mode = (SDL_strchr(mode, 'a') != NULL) ? OPEN_ALWAYS : 0;

    w_right = (a_mode || SDL_strchr(mode, '+')

               || truncate) ? GENERIC_WRITE : 0;

    if (!r_right && !w_right)   /* inconsistent mode */

        return -1;              /* failed (invalid call) */

        (char *) SDL_malloc(READAHEAD_BUFFER_SIZE);

        SDL_OutOfMemory();

        return -1;

    }

#ifdef _WIN32_WCE

    {

        size_t size = SDL_strlen(filename) + 1;

        wchar_t *filenameW = SDL_stack_alloc(wchar_t, size);

        if (MultiByteToWideChar(CP_UTF8, 0, filename, -1, filenameW, size) ==

            0) {

            SDL_stack_free(filenameW);

            SDL_SetError("Unable to convert filename to Unicode");

            return -1;

        }

        h = CreateFile(filenameW, (w_right | r_right),

                       (w_right) ? 0 : FILE_SHARE_READ, NULL,

                       (must_exist | truncate | a_mode),

                       FILE_ATTRIBUTE_NORMAL, NULL);

        SDL_stack_free(filenameW);

    }

#else

    /* Do not open a dialog box if failure */

    old_error_mode =

        SetErrorMode(SEM_NOOPENFILEERRORBOX | SEM_FAILCRITICALERRORS);

    h = CreateFile(filename, (w_right | r_right),

                   (w_right) ? 0 : FILE_SHARE_READ, NULL,

                   (must_exist | truncate | a_mode), FILE_ATTRIBUTE_NORMAL,

                   NULL);

    /* restore old behaviour */

    SetErrorMode(old_error_mode);

#endif /* _WIN32_WCE */

    if (h == INVALID_HANDLE_VALUE) {

        SDL_SetError("Couldn't open %s", filename);

        return -2;              /* failed (CreateFile) */

    }

    return 0;                   /* ok */

}

static long SDLCALL

{

    long file_pos;

        return -1;

    }

    /* FIXME: We may be able to satisfy the seek within buffered data */

    }

    switch (whence) {

    case RW_SEEK_SET:

        break;

    case RW_SEEK_CUR:

        break;

    case RW_SEEK_END:

        break;

    default:

        return -1;

    }

    file_pos =

    if (file_pos != INVALID_SET_FILE_POINTER)

        return file_pos;        /* success */

    SDL_Error(SDL_EFSEEK);

    return -1;                  /* error */

}

static size_t SDLCALL

{

    size_t total_need;

    size_t total_read = 0;

    size_t read_ahead;

    DWORD byte_read;

    total_need = size * maxnum;

        || !total_need)

        return 0;

        read_ahead =

        SDL_memcpy(ptr, data, read_ahead);

        if (read_ahead == total_need) {

            return maxnum;

        }

        ptr = (char *) ptr + read_ahead;

        total_need -= read_ahead;

        total_read += read_ahead;

    }

    if (total_need < READAHEAD_BUFFER_SIZE) {

        if (!ReadFile

             READAHEAD_BUFFER_SIZE, &byte_read, NULL)) {

            SDL_Error(SDL_EFREAD);

            return 0;

        }

        read_ahead = SDL_min(total_need, (int) byte_read);

        total_read += read_ahead;

    } else {

        if (!ReadFile

            SDL_Error(SDL_EFREAD);

            return 0;

        }

        total_read += byte_read;

    }

    return (total_read / size);

}

static size_t SDLCALL

                 size_t num)

{

    size_t total_bytes;

    DWORD byte_written;

    size_t nwritten;

    total_bytes = size * num;

        || total_bytes <= 0 || !size)

        return 0;

                       FILE_CURRENT);

    }

    /* if in append mode, we must go to the EOF before write */

            INVALID_SET_FILE_POINTER) {

            SDL_Error(SDL_EFWRITE);

            return 0;

        }

    }

    if (!WriteFile

        SDL_Error(SDL_EFWRITE);

        return 0;

    }

    nwritten = byte_written / size;

    return nwritten;

}

static int SDLCALL

{

    if (context) {

        }

        }

        SDL_FreeRW(context);

    }

    return (0);

}

#ifdef HAVE_STDIO_H

/* Functions to read/write stdio file pointers */

static long SDLCALL

stdio_seek(SDL_RWops * context, long offset, int whence)

{

    if (fseek(context->hidden.stdio.fp, offset, whence) == 0) {

        return (ftell(context->hidden.stdio.fp));

    } else {

        SDL_Error(SDL_EFSEEK);

        return (-1);

    }

}

static size_t SDLCALL

stdio_read(SDL_RWops * context, void *ptr, size_t size, size_t maxnum)

{

    size_t nread;

    nread = fread(ptr, size, maxnum, context->hidden.stdio.fp);

    if (nread == 0 && ferror(context->hidden.stdio.fp)) {

        SDL_Error(SDL_EFREAD);

    }

    return (nread);

}

static size_t SDLCALL

stdio_write(SDL_RWops * context, const void *ptr, size_t size, size_t num)

{

    size_t nwrote;

    nwrote = fwrite(ptr, size, num, context->hidden.stdio.fp);

    if (nwrote == 0 && ferror(context->hidden.stdio.fp)) {

        SDL_Error(SDL_EFWRITE);

    }

    return (nwrote);

}

static int SDLCALL

stdio_close(SDL_RWops * context)

{

    int status = 0;

    if (context) {

        if (context->hidden.stdio.autoclose) {

            /* WARNING:  Check the return value here! */

            if (fclose(context->hidden.stdio.fp) != 0) {

                SDL_Error(SDL_EFWRITE);

                status = -1;

            }

        }

        SDL_FreeRW(context);

    }

    return status;

}

#endif /* !HAVE_STDIO_H */

/* Functions to read/write memory pointers */

static long SDLCALL

mem_seek(SDL_RWops * context, long offset, int whence)

{

    Uint8 *newpos;

    switch (whence) {

    case RW_SEEK_SET:

        newpos = context->hidden.mem.base + offset;

        break;

    case RW_SEEK_CUR:

        newpos = context->hidden.mem.here + offset;

        break;

    case RW_SEEK_END:

        newpos = context->hidden.mem.stop + offset;

        break;

    default:

        SDL_SetError("Unknown value for 'whence'");

        return (-1);

    }

    if (newpos < context->hidden.mem.base) {

        newpos = context->hidden.mem.base;

    }

    if (newpos > context->hidden.mem.stop) {

        newpos = context->hidden.mem.stop;

    }

    context->hidden.mem.here = newpos;

    return (long)(context->hidden.mem.here - context->hidden.mem.base);

}

static size_t SDLCALL

mem_read(SDL_RWops * context, void *ptr, size_t size, size_t maxnum)

{

    size_t total_bytes;

    size_t mem_available;

    total_bytes = (maxnum * size);

    if ((maxnum <= 0) || (size <= 0)

        || ((total_bytes / maxnum) != (size_t) size)) {

        return 0;

    }

    mem_available = (context->hidden.mem.stop - context->hidden.mem.here);

    if (total_bytes > mem_available) {

        total_bytes = mem_available;

    }

    SDL_memcpy(ptr, context->hidden.mem.here, total_bytes);

    context->hidden.mem.here += total_bytes;

    return (total_bytes / size);

}

static size_t SDLCALL

mem_write(SDL_RWops * context, const void *ptr, size_t size, size_t num)

{

    if ((context->hidden.mem.here + (num * size)) > context->hidden.mem.stop) {

        num = (context->hidden.mem.stop - context->hidden.mem.here) / size;

    }

    SDL_memcpy(context->hidden.mem.here, ptr, num * size);

    context->hidden.mem.here += num * size;

    return (num);

}

static size_t SDLCALL

mem_writeconst(SDL_RWops * context, const void *ptr, size_t size, size_t num)

{

    SDL_SetError("Can't write to read-only memory");

    return (-1);

}

static int SDLCALL

mem_close(SDL_RWops * context)

{

    if (context) {

        SDL_FreeRW(context);

    }

    return (0);

}

/* Functions to create SDL_RWops structures from various data sources */

SDL_RWops *

SDL_RWFromFile(const char *file, const char *mode)

{

    SDL_RWops *rwops = NULL;

#ifdef HAVE_STDIO_H

    FILE *fp = NULL;

#endif

    if (!file || !*file || !mode || !*mode) {

        SDL_SetError("SDL_RWFromFile(): No file or no mode specified");

        return NULL;

    }

    rwops = SDL_AllocRW();

    if (!rwops)

        return NULL;            /* SDL_SetError already setup by SDL_AllocRW() */

        SDL_FreeRW(rwops);

        return NULL;

    }

#elif HAVE_STDIO_H

	#ifdef __APPLE__

	fp = SDL_OpenFPFromBundleOrFallback(file, mode);

    #else

	fp = fopen(file, mode);

	#endif

	if (fp == NULL) {

        SDL_SetError("Couldn't open %s", file);

    } else {

        rwops = SDL_RWFromFP(fp, 1);

    }

#else

    SDL_SetError("SDL not compiled with stdio support");

#endif /* !HAVE_STDIO_H */

    return (rwops);

}