/* Copyright  (C) 2010-2015 The RetroArch team
 *
 * ---------------------------------------------------------------------------------------
 * The following license statement only applies to this file (retro_file.c).
 * ---------------------------------------------------------------------------------------
 *
 * Permission is hereby granted, free of charge,
 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#if defined(_WIN32)
#  ifdef _MSC_VER
#    define setmode _setmode
#  endif
#  ifdef _XBOX
#    include <xtl.h>
#    define INVALID_FILE_ATTRIBUTES -1
#  else
#    include <io.h>
#    include <fcntl.h>
#    include <direct.h>
#    include <windows.h>
#  endif
#elif defined(VITA)
#  include <psp2/io/fcntl.h>
#  include <psp2/io/dirent.h>

#define PSP_O_RDONLY PSP2_O_RDONLY
#define PSP_O_RDWR   PSP2_O_RDWR
#define PSP_O_CREAT  PSP2_O_CREAT
#define PSP_O_WRONLY PSP2_O_WRONLY
#define PSP_O_TRUNC  PSP2_O_TRUNC
#else
#  if defined(PSP)
#    include <pspiofilemgr.h>
#  endif
#  include <sys/types.h>
#  include <sys/stat.h>
#  include <dirent.h>
#  include <unistd.h>
#endif

#ifdef __CELLOS_LV2__
#include <cell/cell_fs.h>
#else
#include <fcntl.h>
#endif

#include <retro_file.h>
#include <memmap.h>

#if 1
#define HAVE_BUFFERED_IO 1
#endif

struct RFILE
{
   unsigned hints;
#if defined(PSP) || defined(VITA)
   SceUID fd;
#elif defined(__CELLOS_LV2__)
   int fd;
#else
#if defined(HAVE_BUFFERED_IO)
   FILE *fp;
#endif
#if defined(HAVE_MMAP)
   uint8_t *mapped;
   uint64_t mappos;
   uint64_t mapsize;
#endif
   int fd;
#endif
};

int retro_get_fd(RFILE *stream)
{
   if (!stream)
      return -1;
#if defined(VITA) || defined(PSP) || defined(__CELLOS_LV2__)
   return stream->fd;
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
      return fileno(stream->fp);
#endif
   return stream->fd;
#endif
}

RFILE *retro_fopen(const char *path, unsigned mode, ssize_t len)
{
   int            flags = 0;
   int         mode_int = 0;
   const char *mode_str = NULL;
   RFILE        *stream = (RFILE*)calloc(1, sizeof(*stream));

   if (!stream)
      return NULL;

   (void)mode_str;
   (void)mode_int;
   (void)flags;

   stream->hints = mode;

#ifdef HAVE_MMAP
   if (stream->hints & RFILE_HINT_MMAP && (stream->hints & 0xff) == RFILE_MODE_READ)
      stream->hints |= RFILE_HINT_UNBUFFERED;
   else
#endif
      stream->hints &= ~RFILE_HINT_MMAP;

   switch (mode & 0xff)
   {
      case RFILE_MODE_READ:
#if defined(VITA) || defined(PSP)
         mode_int = 0777;
         flags    = PSP_O_RDONLY;
#elif defined(__CELLOS_LV2__)
         mode_int = 0777;
         flags    = CELL_FS_O_RDONLY;
#else
#if defined(HAVE_BUFFERED_IO)
         if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
            mode_str = "rb";
#endif
         /* No "else" here */
         flags    = O_RDONLY;
#endif
         break;
      case RFILE_MODE_WRITE:
#if defined(VITA) || defined(PSP)
         mode_int = 0777;
         flags    = PSP_O_CREAT | PSP_O_WRONLY | PSP_O_TRUNC;
#elif defined(__CELLOS_LV2__)
         mode_int = 0777;
         flags    = CELL_FS_O_CREAT | CELL_FS_O_WRONLY | CELL_FS_O_TRUNC;
#else
#if defined(HAVE_BUFFERED_IO)
         if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
            mode_str = "wb";
#endif
         else
         {
            flags    = O_WRONLY | O_CREAT | O_TRUNC;
#ifndef _WIN32
            flags   |=  S_IRUSR | S_IWUSR;
#endif
         }
#endif
         break;
      case RFILE_MODE_READ_WRITE:
#if defined(VITA) || defined(PSP)
         mode_int = 0777;
         flags    = PSP_O_RDWR;
#elif defined(__CELLOS_LV2__)
         mode_int = 0777;
         flags    = CELL_FS_O_RDWR;
#else
#if defined(HAVE_BUFFERED_IO)
         if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
            mode_str = "w+";
#endif
         else
         {
            flags    = O_RDWR;
#ifdef _WIN32
            flags   |= O_BINARY;
#endif
         }
#endif
         break;
   }

#if defined(VITA) || defined(PSP)
   stream->fd = sceIoOpen(path, flags, mode_int);
#elif defined(__CELLOS_LV2__)
   cellFsOpen(path, flags, &stream->fd, NULL, 0);
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
   {
      stream->fp = fopen(path, mode_str);
      if (!stream->fp)
         goto error;
   }
   else
#endif
   {
      stream->fd = open(path, flags);
      if (stream->fd == -1)
         goto error;
#ifdef HAVE_MMAP
      if (stream->hints & RFILE_HINT_MMAP)
      {
         stream->mappos  = 0;
         stream->mapped  = NULL;
         stream->mapsize = retro_fseek(stream, 0, SEEK_END);

         if (stream->mapsize == (uint64_t)-1)
            goto error;

         retro_frewind(stream);

         stream->mapped = (uint8_t*)mmap((void*)0, stream->mapsize, PROT_READ,  MAP_SHARED, stream->fd, 0);

         if (stream->mapped == MAP_FAILED)
            stream->hints &= ~RFILE_HINT_MMAP;
      }
#endif
   }
#endif

#if defined(VITA) || defined(PSP) || defined(__CELLOS_LV2__)
   if (stream->fd == -1)
      goto error;
#endif

   return stream;

error:
   retro_fclose(stream);
   return NULL;
}

ssize_t retro_fseek(RFILE *stream, ssize_t offset, int whence)
{
   int ret = 0;
   if (!stream)
      return -1;

   (void)ret;

#if defined(VITA) || defined(PSP)
   ret = sceIoLseek(stream->fd, (SceOff)offset, whence);
   if (ret == -1)
      return -1;
   return 0;
#elif defined(__CELLOS_LV2__)
   uint64_t pos = 0;
   if (cellFsLseek(stream->fd, offset, whence, &pos) != CELL_FS_SUCCEEDED)
      return -1;
   return 0;
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
      return fseek(stream->fp, (long)offset, whence);
   else
#endif
#ifdef HAVE_MMAP
      /* Need to check stream->mapped because this function is called in retro_fopen() */
      if (stream->mapped && stream->hints & RFILE_HINT_MMAP)
      {
         /* fseek() returns error on under/overflow but allows cursor > EOF for
            read-only file descriptors. */
         switch (whence)
         {
            case SEEK_SET:
               if (offset < 0)
                  return -1;

               stream->mappos = offset;
               break;

            case SEEK_CUR:
               if ((offset < 0 && stream->mappos + offset > stream->mappos) ||
                   (offset > 0 && stream->mappos + offset < stream->mappos))
                  return -1;

               stream->mappos += offset;
               break;

            case SEEK_END:
               if (stream->mapsize + offset < stream->mapsize)
                  return -1;

               stream->mappos = stream->mapsize + offset;

               break;
         }

         return stream->mappos;
      }
      else
#endif
      {
         ret = lseek(stream->fd, offset, whence);
         return ret < 0 ? -1 : ret;
      }
#endif
}

ssize_t retro_ftell(RFILE *stream)
{
   if (!stream)
      return -1;
#if defined(VITA) || defined(PSP)
   return sceIoLseek(stream->fd, 0, SEEK_CUR);
#elif defined(__CELLOS_LV2__)
   uint64_t pos = 0;
   if (cellFsLseek(stream->fd, 0, CELL_FS_SEEK_CUR, &pos) != CELL_FS_SUCCEEDED)
      return -1;
   return 0;
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
      return ftell(stream->fp);
   else
#endif
#ifdef HAVE_MMAP
      /* Need to check stream->mapped because this function is called in retro_fopen() */
      if (stream->mapped && stream->hints & RFILE_HINT_MMAP)
         return stream->mappos;
      else
#endif
         return lseek(stream->fd, 0, SEEK_CUR);
#endif
}

void retro_frewind(RFILE *stream)
{
   retro_fseek(stream, 0L, SEEK_SET);
}

ssize_t retro_fread(RFILE *stream, void *s, size_t len)
{
   if (!stream || !s)
      return -1;
#if defined(VITA) || defined(PSP)
   return sceIoRead(stream->fd, s, len);
#elif defined(__CELLOS_LV2__)
   uint64_t bytes_written;
   if (cellFsRead(stream->fd, s, len, &bytes_written) != CELL_FS_SUCCEEDED)
      return -1;
   return bytes_written;
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
      return fread(s, 1, len, stream->fp);
   else
#endif
#ifdef HAVE_MMAP
      if (stream->hints & RFILE_HINT_MMAP)
      {
         if (stream->mappos > stream->mapsize)
            return -1;

         if (stream->mappos + len > stream->mapsize)
            len = stream->mapsize - stream->mappos;

         memcpy(s, &stream->mapped[stream->mappos], len);
         stream->mappos += len;

         return len;
      }
      else
#endif
         return read(stream->fd, s, len);
#endif
}

ssize_t retro_fwrite(RFILE *stream, const void *s, size_t len)
{
   if (!stream)
      return -1;
#if defined(VITA) || defined(PSP)
   return sceIoWrite(stream->fd, s, len);
#elif defined(__CELLOS_LV2__)
   uint64_t bytes_written;
   if (cellFsWrite(stream->fd, s, len, &bytes_written) != CELL_FS_SUCCEEDED)
      return -1;
   return bytes_written;
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
      return fwrite(s, 1, len, stream->fp);
   else
#endif
#ifdef HAVE_MMAP
      if (stream->hints & RFILE_HINT_MMAP)
         return -1;
      else
#endif
         return write(stream->fd, s, len);
#endif
}

int retro_fclose(RFILE *stream)
{
   if (!stream)
      return -1;

#if defined(VITA) || defined(PSP)
   if (stream->fd > 0)
      sceIoClose(stream->fd);
#elif defined(__CELLOS_LV2__)
   if (stream->fd > 0)
      cellFsClose(stream->fd);
#else
#if defined(HAVE_BUFFERED_IO)
   if ((stream->hints & RFILE_HINT_UNBUFFERED) == 0)
   {
      if (stream->fp)
         fclose(stream->fp);
   }
   else
#endif
#ifdef HAVE_MMAP
      if (stream->hints & RFILE_HINT_MMAP)
         munmap(stream->mapped, stream->mapsize);
#endif

      if (stream->fd > 0)
         close(stream->fd);
#endif
   free(stream);

   return 0;
}

/**
 * retro_read_file:
 * @path             : path to file.
 * @buf              : buffer to allocate and read the contents of the
 *                     file into. Needs to be freed manually.
 *
 * Read the contents of a file into @buf.
 *
 * Returns: number of items read, -1 on error.
 */
int retro_read_file(const char *path, void **buf, ssize_t *len)
{
   ssize_t ret              = 0;
   ssize_t content_buf_size = 0;
   void *content_buf        = NULL;
   RFILE *file              = retro_fopen(path, RFILE_MODE_READ, -1);

   if (!file)
   {
#if __STDC_VERSION__ >= 199901L
      fprintf(stderr, "%s: Failed to open %s: %s\n", __FUNCTION__, path, strerror(errno));
#else
      fprintf(stderr, "Failed to open %s: %s\n", path, strerror(errno));
#endif
      goto error;
   }

   if (retro_fseek(file, 0, SEEK_END) != 0)
      goto error;

   content_buf_size = retro_ftell(file);
   if (content_buf_size < 0)
      goto error;

   retro_frewind(file);

   content_buf = malloc(content_buf_size + 1);

   if (!content_buf)
      goto error;

   ret = retro_fread(file, content_buf, content_buf_size);
   if (ret < 0)
   {
#if __STDC_VERSION__ >= 199901L
      fprintf(stderr, "%s: Failed to read %s: %s\n", __FUNCTION__, path, strerror(errno));
#else
      fprintf(stderr, "Failed to read %s: %s\n", path, strerror(errno));
#endif
      goto error;
   }

   retro_fclose(file);

   *buf    = content_buf;

   /* Allow for easy reading of strings to be safe.
    * Will only work with sane character formatting (Unix). */
   ((char*)content_buf)[content_buf_size] = '\0';

   if (len)
      *len = ret;

   return 1;

error:
   if (file)
      retro_fclose(file);
   if (content_buf)
      free(content_buf);
   if (len)
      *len = -1;
   *buf = NULL;
   return 0;
}

/**
 * retro_write_file:
 * @path             : path to file.
 * @data             : contents to write to the file.
 * @size             : size of the contents.
 *
 * Writes data to a file.
 *
 * Returns: true (1) on success, false (0) otherwise.
 */
bool retro_write_file(const char *path, const void *data, ssize_t size)
{
   ssize_t ret   = 0;
   RFILE *file   = retro_fopen(path, RFILE_MODE_WRITE, -1);
   if (!file)
      return false;

   ret = retro_fwrite(file, data, size);
   retro_fclose(file);

   return (ret == size);
}