/*
  This file is part of Deadbeef Player source code
  http://deadbeef.sourceforge.net

  standard file vfs implementation

  Copyright (C) 2009-2013 Alexey Yakovenko

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  Alexey Yakovenko waker@users.sourceforge.net
*/
#include "deadbeef.h"
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#ifndef __linux__
#define off64_t off_t
#define lseek64 lseek
#define O_LARGEFILE 0
#endif

//#define USE_STDIO

static DB_functions_t *deadbeef;
typedef struct {
    DB_vfs_t *vfs;
#ifdef USE_STDIO
    FILE *stream;
#else
    int stream;
    int64_t offs;
#endif
} STDIO_FILE;

static DB_vfs_t plugin;

static DB_FILE *
stdio_open (const char *fname) {
    if (!memcmp (fname, "file://", 7)) {
        fname += 7;
    }
#ifdef USE_STDIO
    FILE *file = fopen (fname, "rb");
    if (!file) {
        return NULL;
    }
#else
    int file = open (fname, O_LARGEFILE);
    if (file == -1) {
        return NULL;
    }
#endif
    STDIO_FILE *fp = malloc (sizeof (STDIO_FILE));
    fp->vfs = &plugin;
    fp->stream = file;
#ifndef USE_STDIO
    fp->offs = 0;
#endif
    return (DB_FILE*)fp;
}

static void
stdio_close (DB_FILE *stream) {
    assert (stream);
#ifdef USE_STDIO
    fclose (((STDIO_FILE *)stream)->stream);
#else
    close (((STDIO_FILE *)stream)->stream);
#endif
    free (stream);
}

static size_t
stdio_read (void *ptr, size_t size, size_t nmemb, DB_FILE *stream) {
    assert (stream);
    assert (ptr);
#ifdef USE_STDIO
    return fread (ptr, size, nmemb, ((STDIO_FILE*)stream)->stream);
#else
    int res = read (((STDIO_FILE*)stream)->stream, ptr, size*nmemb);
    if (res == -1) {
        return 0;
    }
    ((STDIO_FILE*)stream)->offs += res;
    return res / size;
#endif
}

static int
stdio_seek (DB_FILE *stream, int64_t offset, int whence) {
    assert (stream);
#ifdef USE_STDIO
    return fseek (((STDIO_FILE *)stream)->stream, offset, whence);
#else
    off64_t res = lseek64 (((STDIO_FILE *)stream)->stream, offset, whence);
    if (res == -1) {
        return -1;
    }
//    printf ("lseek res: %lld (%lld, %d, prev=%lld)\n", res, offset, whence,  ((STDIO_FILE*)stream)->offs);
    ((STDIO_FILE*)stream)->offs = res; 
#endif
    return 0;
}

static int64_t
stdio_tell (DB_FILE *stream) {
    assert (stream);
#ifdef USE_STDIO
    return ftell (((STDIO_FILE*)stream)->stream);
#else
    return ((STDIO_FILE*)stream)->offs;
#endif
}

static void
stdio_rewind (DB_FILE *stream) {
    assert (stream);
#ifdef USE_STDIO
    rewind (((STDIO_FILE*)stream)->stream);
#else
    stdio_seek (stream, 0, SEEK_SET);
#endif
}

static int64_t
stdio_getlength (DB_FILE *stream) {
    assert (stream);
    STDIO_FILE *f = (STDIO_FILE *)stream;
#ifdef USE_STDIO
    size_t offs = ftell (f->stream);
    fseek (f->stream, 0, SEEK_END);
    size_t l = ftell (f->stream);
    fseek (f->stream, offs, SEEK_SET);
    return l;
#else
    int64_t size = lseek64 (f->stream, 0, SEEK_END);
    lseek64 (f->stream, f->offs, SEEK_SET);
    return size;
#endif
}

const char *
stdio_get_content_type (DB_FILE *stream) {
    return NULL;
}

int
stdio_is_streaming (void) {
    return 0;
}

// standard stdio vfs
static DB_vfs_t plugin = {
    DB_PLUGIN_SET_API_VERSION
    .plugin.version_major = 1,
    .plugin.version_minor = 0,
    .plugin.type = DB_PLUGIN_VFS,
    .plugin.name = "stdio vfs",
    .plugin.id = "vfs_stdio",
    .plugin.descr = "Standard IO plugin\nUsed for reading normal local files\nIt is statically linked, so you can't delete it.",
    .plugin.copyright = 
        "Copyright (C) 2009-2013 Alexey Yakovenko <waker@users.sourceforge.net>\n"
        "\n"
        "This program is free software; you can redistribute it and/or\n"
        "modify it under the terms of the GNU General Public License\n"
        "as published by the Free Software Foundation; either version 2\n"
        "of the License, or (at your option) any later version.\n"
        "\n"
        "This program is distributed in the hope that it will be useful,\n"
        "but WITHOUT ANY WARRANTY; without even the implied warranty of\n"
        "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n"
        "GNU General Public License for more details.\n"
        "\n"
        "You should have received a copy of the GNU General Public License\n"
        "along with this program; if not, write to the Free Software\n"
        "Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.\n"
    ,
    .plugin.website = "http://deadbeef.sf.net",
    .open = stdio_open,
    .close = stdio_close,
    .read = stdio_read,
    .seek = stdio_seek,
    .tell = stdio_tell,
    .rewind = stdio_rewind,
    .getlength = stdio_getlength,
    .get_content_type = stdio_get_content_type,
    .is_streaming = stdio_is_streaming
};

DB_plugin_t *
stdio_load (DB_functions_t *api) {
    deadbeef = api;
    return DB_PLUGIN (&plugin);
}