/*****************************************************************************

 * file.c: file input (file: access plug-in)

 *****************************************************************************

 * Copyright (C) 2001-2006 VLC authors and VideoLAN

 * Copyright © 2006-2007 Rémi Denis-Courmont

 *

 * Authors: Christophe Massiot <massiot@via.ecp.fr>

 *          Rémi Denis-Courmont

 *

 * This program 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 program 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 program; if not, write to the Free Software Foundation,

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

 *****************************************************************************/

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <assert.h>

#include <errno.h>

#include <limits.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#ifdef HAVE_FSTATVFS

#   include <sys/statvfs.h>

#   if defined (HAVE_SYS_MOUNT_H)

#      include <sys/param.h>

#      include <sys/mount.h>

#   endif

#endif

#ifdef HAVE_LINUX_MAGIC_H

#   include <sys/vfs.h>

#   include <linux/magic.h>

#endif

#if defined( _WIN32 )

#   include <io.h>

#   include <ctype.h>

#else

#   include <unistd.h>

#endif

#include <vlc_common.h>

#include "fs.h"

#include <vlc_access.h>

#include <vlc_interrupt.h>

#ifdef _WIN32

# include <vlc_charset.h>

#endif

#include <vlc_fs.h>

#include <vlc_url.h>

typedef struct

{

    int fd;

    bool b_pace_control;

} access_sys_t;

#if !defined (_WIN32) && !defined (__OS2__)

static bool IsRemote (int fd)

{

#if defined(__APPLE__)

    /* This has to preceed the general fstatvfs implmentation below,

     * as even though Darwin has fstatvfs, it does not expose the

     * MNT_LOCAL in the statvfs.f_flag field.

     */

    struct statfs sfs;

    if (fstatfs (fd, &sfs))

        return false;

    return !((sfs.f_flags & MNT_LOCAL) == MNT_LOCAL);

#elif defined (HAVE_FSTATVFS) && defined (MNT_LOCAL)

    struct statvfs stf;

    if (fstatvfs (fd, &stf))

        return false;

    /* fstatvfs() is in POSIX, but MNT_LOCAL is not */

    return !(stf.f_flag & MNT_LOCAL);

#elif defined (HAVE_LINUX_MAGIC_H)

    struct statfs stf;

    if (fstatfs (fd, &stf))

        return false;

    switch ((unsigned long)stf.f_type)

    {

        case AFS_SUPER_MAGIC:

        case CODA_SUPER_MAGIC:

        case NCP_SUPER_MAGIC:

        case NFS_SUPER_MAGIC:

        case SMB_SUPER_MAGIC:

        case 0xFF534D42 /*CIFS_MAGIC_NUMBER*/:

            return true;

    }

    return false;

#else

    (void)fd;

    return false;

#endif

}

# define IsRemote(fd,path) IsRemote(fd)

#elif defined(_WIN32)

static bool IsRemote(int fd, const char *path)

{

    VLC_UNUSED(fd);

    size_t len = strlen(path);

    if (len < 2)

        return false;

    if (path[0] == '\\' && path[1] == '\\')

        return true;

#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) ||  NTDDI_VERSION >= NTDDI_WIN10_RS3

    if (path[1] == ':')

    {

        char drive[4];

        drive[0] = path[0]; // can only be < 0x80 if second char is ':'

        drive[1] = ':';

        drive[2] = '\\';

        drive[3] = '\0';

        UINT driveType = GetDriveTypeA(drive);

        switch (driveType)

        {

            case DRIVE_FIXED:

            case DRIVE_REMOVABLE: // but a floppy drive is slower than network

            case DRIVE_RAMDISK:

            case DRIVE_CDROM:

                return false;

            default:

                return true;

        }

    }

#endif

    return false;

}

#else /* __OS2__ */

static bool IsRemote (const char *path)

{

    return (! strncmp(path, "\\\\", 2));

}

# define IsRemote(fd,path) IsRemote(path)

#endif

#ifndef HAVE_POSIX_FADVISE

# define posix_fadvise(fd, off, len, adv)

#endif

static ssize_t Read (stream_t *, void *, size_t);

static int FileSeek (stream_t *, uint64_t);

static int FileControl (stream_t *, int, va_list);

/*****************************************************************************

 * FileOpen: open the file

 *****************************************************************************/

int FileOpen( vlc_object_t *p_this )

{

    stream_t *p_access = (stream_t*)p_this;

    /* Open file */

    int fd = -1;

    if (!strcasecmp (p_access->psz_name, "fd"))

    {

        char *end;

        unsigned long oldfd = strtoul(p_access->psz_location, &end, 10);

        if (oldfd > INT_MAX)

            errno = EBADF;

        else if (*end == '\0')

            fd = vlc_dup (oldfd);

        else if (*end == '/' && end > p_access->psz_location)

        {

            char *name = vlc_uri_decode_duplicate (end - 1);

            if (name != NULL)

            {

                name[0] = '.';

                fd = vlc_openat (oldfd, name, O_RDONLY | O_NONBLOCK);

                free (name);

            }

        }

    }

    else

    {

        if (unlikely(p_access->psz_filepath == NULL))

            return VLC_EGENERIC;

        fd = vlc_open (p_access->psz_filepath, O_RDONLY | O_NONBLOCK);

    }

    if (fd == -1)

    {

        msg_Err (p_access, "cannot open file %s (%s)",

                 p_access->psz_filepath ? p_access->psz_filepath

                                        : p_access->psz_location,

                 vlc_strerror_c(errno));

        return VLC_EGENERIC;

    }

    struct stat st;

    if (fstat (fd, &st))

    {

        msg_Err (p_access, "read error: %s", vlc_strerror_c(errno));

        goto error;

    }

#if O_NONBLOCK

    /* Force blocking mode back */

    fcntl (fd, F_SETFL, fcntl (fd, F_GETFL) & ~O_NONBLOCK);

#endif

    /* Directories can be opened and read from, but only readdir() knows

     * how to parse the data. The directory plugin will do it. */

    if (S_ISDIR (st.st_mode))

    {

#ifdef HAVE_FDOPENDIR

        DIR *p_dir = fdopendir(fd);

        if (!p_dir) {

            msg_Err (p_access, "fdopendir error: %s", vlc_strerror_c(errno));

            goto error;

        }

        return DirInit (p_access, p_dir);

#else

        msg_Dbg (p_access, "ignoring directory");

        goto error;

#endif

    }

    access_sys_t *p_sys = vlc_obj_malloc(p_this, sizeof (*p_sys));

    if (unlikely(p_sys == NULL))

        goto error;

    p_access->pf_read = Read;

    p_access->pf_block = NULL;

    p_access->pf_control = FileControl;

    p_access->p_sys = p_sys;

    p_sys->fd = fd;

    if (S_ISREG (st.st_mode) || S_ISBLK (st.st_mode))

    {

        p_access->pf_seek = FileSeek;

        p_sys->b_pace_control = true;

        /* Demuxers will need the beginning of the file for probing. */

        posix_fadvise (fd, 0, 4096, POSIX_FADV_WILLNEED);

        /* In most cases, we only read the file once. */

        posix_fadvise (fd, 0, 0, POSIX_FADV_NOREUSE);

#ifdef F_NOCACHE

        fcntl (fd, F_NOCACHE, 0);

#endif

#ifdef F_RDAHEAD

        if (IsRemote(fd, p_access->psz_filepath))

            fcntl (fd, F_RDAHEAD, 0);

        else

            fcntl (fd, F_RDAHEAD, 1);

#endif

    }

    else

    {

        p_access->pf_seek = NULL;

        p_sys->b_pace_control = strcasecmp (p_access->psz_name, "stream");

    }

    return VLC_SUCCESS;

error:

    vlc_close (fd);

    return VLC_EGENERIC;

}

/*****************************************************************************

 * FileClose: close the target

 *****************************************************************************/

void FileClose (vlc_object_t * p_this)

{

    stream_t     *p_access = (stream_t*)p_this;

    if (p_access->pf_read == NULL)

    {

        DirClose (p_this);

        return;

    }

    access_sys_t *p_sys = p_access->p_sys;

    vlc_close (p_sys->fd);

}

static ssize_t Read (stream_t *p_access, void *p_buffer, size_t i_len)

{

    access_sys_t *p_sys = p_access->p_sys;

    int fd = p_sys->fd;

    ssize_t val = vlc_read_i11e (fd, p_buffer, i_len);

    if (val < 0)

    {

        switch (errno)

        {

            case EINTR:

            case EAGAIN:

                return -1;

        }

        msg_Err (p_access, "read error: %s", vlc_strerror_c(errno));

        val = 0;

    }

    return val;

}

/*****************************************************************************

 * Seek: seek to a specific location in a file

 *****************************************************************************/

static int FileSeek (stream_t *p_access, uint64_t i_pos)

{

    access_sys_t *sys = p_access->p_sys;

    if (lseek(sys->fd, i_pos, SEEK_SET) == (off_t)-1)

        return VLC_EGENERIC;

    return VLC_SUCCESS;

}

/*****************************************************************************

 * Control:

 *****************************************************************************/

static int FileControl( stream_t *p_access, int i_query, va_list args )

{

    access_sys_t *p_sys = p_access->p_sys;

    bool    *pb_bool;

    vlc_tick_t *pi_64;

    switch( i_query )

    {

        case STREAM_CAN_SEEK:

        case STREAM_CAN_FASTSEEK:

            pb_bool = va_arg( args, bool * );

            *pb_bool = (p_access->pf_seek != NULL);

            break;

        case STREAM_CAN_PAUSE:

        case STREAM_CAN_CONTROL_PACE:

            pb_bool = va_arg( args, bool * );

            *pb_bool = p_sys->b_pace_control;

            break;

        case STREAM_GET_SIZE:

        case STREAM_GET_MTIME:

        {

            struct stat st;

            if (fstat (p_sys->fd, &st) || !S_ISREG(st.st_mode))

                return VLC_EGENERIC;

            const uint64_t stat =

                (i_query == STREAM_GET_SIZE) ? st.st_size : st.st_mtime;

            *va_arg( args, uint64_t * ) = stat;

            break;

        }

        case STREAM_GET_PTS_DELAY:

            pi_64 = va_arg( args, vlc_tick_t * );

            if (IsRemote (p_sys->fd, p_access->psz_filepath))

                *pi_64 = VLC_TICK_FROM_MS(

                        var_InheritInteger (p_access, "network-caching") );

            else

                *pi_64 = VLC_TICK_FROM_MS(

                        var_InheritInteger (p_access, "file-caching") );

            break;

        case STREAM_SET_PAUSE_STATE:

            /* Nothing to do */

            break;

        default:

            return VLC_EGENERIC;

    }

    return VLC_SUCCESS;

}