/*

 * Copyright (C) 2002 Samuel Hocevar <sam@zoy.org>,

 *                    Håkan Hjort <d95hjort@dtek.chalmers.se>

 *

 * This file is part of libdvdread.

 *

 * libdvdread is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * libdvdread 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with libdvdread; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include "config.h"                  /* Required for HAVE_DVDCSS_DVDCSS_H */

#include <stdio.h>                               /* fprintf */

#include <stdlib.h>                              /* free */

#include <fcntl.h>                               /* open */

#include <unistd.h>                              /* lseek */

#include "dvdread/dvd_reader.h"      /* DVD_VIDEO_LB_LEN */

#include "dvd_input.h"

/* The function pointers that is the exported interface of this file. */

dvd_input_t (*dvdinput_open)  (const char *, void *, dvd_reader_stream_cb *);

int         (*dvdinput_close) (dvd_input_t);

int         (*dvdinput_seek)  (dvd_input_t, int);

int         (*dvdinput_title) (dvd_input_t, int);

int         (*dvdinput_read)  (dvd_input_t, void *, int, int);

char *      (*dvdinput_error) (dvd_input_t);

#ifdef HAVE_DVDCSS_DVDCSS_H

/* linking to libdvdcss */

# include <dvdcss/dvdcss.h>

# define DVDcss_open_stream(a, b) \

    dvdcss_open_stream((void*)(a), (dvdcss_stream_cb*)(b))

# define DVDcss_open(a) dvdcss_open((char*)(a))

# define DVDcss_close   dvdcss_close

# define DVDcss_seek    dvdcss_seek

# define DVDcss_read    dvdcss_read

# define DVDcss_error   dvdcss_error

#else

/* dlopening libdvdcss */

# if defined(HAVE_DLFCN_H) && !defined(USING_BUILTIN_DLFCN)

#  include <dlfcn.h>

# else

# if defined(WIN32)

/* Only needed on MINGW at the moment */

#  include "../msvc/contrib/dlfcn.c"

# endif

#endif

typedef struct dvdcss_s *dvdcss_t;

typedef struct dvdcss_stream_cb dvdcss_stream_cb;

static dvdcss_t (*DVDcss_open_stream) (void *, dvdcss_stream_cb *);

static dvdcss_t (*DVDcss_open)  (const char *);

static int      (*DVDcss_close) (dvdcss_t);

static int      (*DVDcss_seek)  (dvdcss_t, int, int);

static int      (*DVDcss_read)  (dvdcss_t, void *, int, int);

static char *   (*DVDcss_error) (dvdcss_t);

#define DVDCSS_SEEK_KEY (1 << 1)

#endif

/* The DVDinput handle, add stuff here for new input methods. */

struct dvd_input_s {

  /* libdvdcss handle */

  dvdcss_t dvdcss;

  /* dummy file input */

  int fd;

};

/**

 * initialize and open a DVD (device or file or stream_cb)

 */

static dvd_input_t css_open(const char *target,

                            void *stream, dvd_reader_stream_cb *stream_cb)

{

  dvd_input_t dev;

  /* Allocate the handle structure */

  dev = malloc(sizeof(*dev));

  if(dev == NULL) {

    fprintf(stderr, "libdvdread: Could not allocate memory.\n");

    return NULL;

  }

  /* Really open it with libdvdcss */

  if(target)

      dev->dvdcss = DVDcss_open(target);

  else if(stream && stream_cb) {

#ifdef HAVE_DVDCSS_DVDCSS_H

      dev->dvdcss = DVDcss_open_stream(stream, (dvdcss_stream_cb *)stream_cb);

#else

      dev->dvdcss = DVDcss_open_stream ?

                    DVDcss_open_stream(stream, (dvdcss_stream_cb *)stream_cb) :

                    NULL;

#endif

  }

  if(dev->dvdcss == 0) {

    fprintf(stderr, "libdvdread: Could not open %s with libdvdcss.\n", target);

    free(dev);

    return NULL;

  }

  return dev;

}

/**

 * return the last error message

 */

static char *css_error(dvd_input_t dev)

{

  return DVDcss_error(dev->dvdcss);

}

/**

 * seek into the device.

 */

static int css_seek(dvd_input_t dev, int blocks)

{

  /* DVDINPUT_NOFLAGS should match the DVDCSS_NOFLAGS value. */

  return DVDcss_seek(dev->dvdcss, blocks, DVDINPUT_NOFLAGS);

}

/**

 * set the block for the beginning of a new title (key).

 */

static int css_title(dvd_input_t dev, int block)

{

  return DVDcss_seek(dev->dvdcss, block, DVDCSS_SEEK_KEY);

}

/**

 * read data from the device.

 */

static int css_read(dvd_input_t dev, void *buffer, int blocks, int flags)

{

  return DVDcss_read(dev->dvdcss, buffer, blocks, flags);

}

/**

 * close the DVD device and clean up the library.

 */

static int css_close(dvd_input_t dev)

{

  int ret;

  ret = DVDcss_close(dev->dvdcss);

  if(ret < 0)

    return ret;

  free(dev);

  return 0;

}

/**

 * initialize and open a DVD device or file.

 */

static dvd_input_t file_open(const char *target,

                             void *stream UNUSED,

                             dvd_reader_stream_cb *stream_cb UNUSED)

{

  dvd_input_t dev;

  if(target == NULL)

    return NULL;

  /* Allocate the library structure */

  dev = malloc(sizeof(*dev));

  if(dev == NULL) {

    fprintf(stderr, "libdvdread: Could not allocate memory.\n");

    return NULL;

  }

  /* Open the device */

#if !defined(WIN32) && !defined(__OS2__)

  dev->fd = open(target, O_RDONLY);

#else

  dev->fd = open(target, O_RDONLY | O_BINARY);

#endif

  if(dev->fd < 0) {

    perror("libdvdread: Could not open input");

    free(dev);

    return NULL;

  }

  return dev;

}

/**

 * return the last error message

 */

static char *file_error(dvd_input_t dev UNUSED)

{

  /* use strerror(errno)? */

  return (char *)"unknown error";

}

/**

 * seek into the device.

 */

static int file_seek(dvd_input_t dev, int blocks)

{

  off_t pos;

  pos = lseek(dev->fd, (off_t)blocks * (off_t)DVD_VIDEO_LB_LEN, SEEK_SET);

  if(pos < 0) {

    return pos;

  }

  /* assert pos % DVD_VIDEO_LB_LEN == 0 */

  return (int) (pos / DVD_VIDEO_LB_LEN);

}

/**

 * set the block for the beginning of a new title (key).

 */

static int file_title(dvd_input_t dev UNUSED, int block UNUSED)

{

  return -1;

}

/**

 * read data from the device.

 */

static int file_read(dvd_input_t dev, void *buffer, int blocks,

		     int flags UNUSED)

{

  size_t len, bytes;

  len = (size_t)blocks * DVD_VIDEO_LB_LEN;

  bytes = 0;

  while(len > 0) {

    ssize_t ret = read(dev->fd, ((char*)buffer) + bytes, len);

    if(ret < 0) {

      /* One of the reads failed, too bad.  We won't even bother

       * returning the reads that went OK, and as in the POSIX spec

       * the file position is left unspecified after a failure. */

      return ret;

    }

    if(ret == 0) {

      /* Nothing more to read.  Return all of the whole blocks, if any.

       * Adjust the file position back to the previous block boundary. */

      off_t over_read = -(bytes % DVD_VIDEO_LB_LEN);

      off_t pos = lseek(dev->fd, over_read, SEEK_CUR);

      if(pos % 2048 != 0)

        fprintf( stderr, "libdvdread: lseek not multiple of 2048! Something is wrong!\n" );

      return (int) (bytes / DVD_VIDEO_LB_LEN);

    }

    len -= ret;

    bytes += ret;

  }

  return blocks;

}

/**

 * close the DVD device and clean up.

 */

static int file_close(dvd_input_t dev)

{

  int ret;

  ret = close(dev->fd);

  if(ret < 0)

    return ret;

  free(dev);

  return 0;

}

/**

 * Setup read functions with either libdvdcss or minimal DVD access.

 */

int dvdinput_setup(void)

{

  void *dvdcss_library = NULL;

#ifdef HAVE_DVDCSS_DVDCSS_H

  /* linking to libdvdcss */

  dvdcss_library = &dvdcss_library;  /* Give it some value != NULL */

#else

  /* dlopening libdvdcss */

#ifdef __APPLE__

  #define CSS_LIB "libdvdcss.2.dylib"

#elif defined(WIN32)

  #define CSS_LIB "libdvdcss-2.dll"

#elif defined(__OS2__)

  #define CSS_LIB "dvdcss2.dll"

#else

  #define CSS_LIB "libdvdcss.so.2"

#endif

  dvdcss_library = dlopen(CSS_LIB, RTLD_LAZY);

  if(dvdcss_library != NULL) {

#if defined(__OpenBSD__) && !defined(__ELF__) || defined(__OS2__)

#define U_S "_"

#else

#define U_S

#endif

    DVDcss_open_stream = (dvdcss_t (*)(void *, dvdcss_stream_cb *))

      dlsym(dvdcss_library, U_S "dvdcss_open_stream");

    DVDcss_open = (dvdcss_t (*)(const char*))

      dlsym(dvdcss_library, U_S "dvdcss_open");

    DVDcss_close = (int (*)(dvdcss_t))

      dlsym(dvdcss_library, U_S "dvdcss_close");

    DVDcss_seek = (int (*)(dvdcss_t, int, int))

      dlsym(dvdcss_library, U_S "dvdcss_seek");

    DVDcss_read = (int (*)(dvdcss_t, void*, int, int))

      dlsym(dvdcss_library, U_S "dvdcss_read");

    DVDcss_error = (char* (*)(dvdcss_t))

      dlsym(dvdcss_library, U_S "dvdcss_error");

    if(dlsym(dvdcss_library, U_S "dvdcss_crack")) {

      fprintf(stderr,

              "libdvdread: Old (pre-0.0.2) version of libdvdcss found.\n"

              "libdvdread: You should get the latest version from "

              "http://www.videolan.org/\n" );

      dlclose(dvdcss_library);

      dvdcss_library = NULL;

    } else if(!DVDcss_open || !DVDcss_close || !DVDcss_seek

              || !DVDcss_read || !DVDcss_error) {

      fprintf(stderr,  "libdvdread: Missing symbols in %s, "

              "this shouldn't happen !\n", CSS_LIB);

      dlclose(dvdcss_library);

      dvdcss_library = NULL;

    }

  }

#endif /* HAVE_DVDCSS_DVDCSS_H */

  if(dvdcss_library != NULL) {

    /*

    char *psz_method = getenv( "DVDCSS_METHOD" );

    char *psz_verbose = getenv( "DVDCSS_VERBOSE" );

    fprintf(stderr, "DVDCSS_METHOD %s\n", psz_method);

    fprintf(stderr, "DVDCSS_VERBOSE %s\n", psz_verbose);

    */

    /* libdvdcss wrapper functions */

    dvdinput_open  = css_open;

    dvdinput_close = css_close;

    dvdinput_seek  = css_seek;

    dvdinput_title = css_title;

    dvdinput_read  = css_read;

    dvdinput_error = css_error;

    return 1;

  } else {

    fprintf(stderr, "libdvdread: Encrypted DVD support unavailable.\n");

    /* libdvdcss replacement functions */

    dvdinput_open  = file_open;

    dvdinput_close = file_close;

    dvdinput_seek  = file_seek;

    dvdinput_title = file_title;

    dvdinput_read  = file_read;

    dvdinput_error = file_error;

    return 0;

  }

}