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

 * dirs.c: XDG directories configuration

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

 * Copyright (C) 2001-2007 VLC authors and VideoLAN

 * Copyright © 2007-2009 Rémi Denis-Courmont

 *

 * Authors: Gildas Bazin <gbazin@videolan.org>

 *

 * 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 <vlc_common.h>

#include "../libvlc.h"

#include "../config/configuration.h"

#include <unistd.h>

#include <pwd.h>

#include <assert.h>

#include <limits.h>

/**

 * Determines the architecture-dependent data directory

 *

 * @return a string (always succeeds).

 */

VLC_WEAK char *config_GetLibDir(void)

{

    return strdup(LIBDIR);

}

char *config_GetSysPath(vlc_sysdir_t type, const char *filename)

{

    static const char env_vars[][17] = {

        [VLC_PKG_DATA_DIR] = "VLC_DATA_PATH",

        [VLC_PKG_LIB_DIR] = "VLC_LIB_PATH",

        [VLC_PKG_LIBEXEC_DIR] = "VLC_LIBEXEC_PATH",

    };

    if (type < ARRAY_SIZE(env_vars)) {

        const char *name = env_vars[type];

         if (*name != '\0') {

             const char *value = getenv(name);

             if (value != NULL) {

                 const char *fmt = (filename != NULL) ? "%s/%s" : "%s";

                 char *filepath;

                 if (unlikely(asprintf(&filepath, fmt, value, filename) == -1))

                     filepath = NULL;

                 return filepath;

             }

         }

    }

    char *libdir = config_GetLibDir();

    if (libdir == NULL)

        return NULL; /* OOM */

    static const char *const dirs[] = {

        [VLC_PKG_DATA_DIR] = PKGDATADIR,

        [VLC_PKG_LIB_DIR] = PKGLIBDIR,

        [VLC_PKG_LIBEXEC_DIR] = PKGLIBEXECDIR,

        [VLC_SYSDATA_DIR] = SYSDATADIR,

        [VLC_LIB_DIR] = LIBDIR,

        [VLC_LIBEXEC_DIR] = LIBEXECDIR,

        [VLC_LOCALE_DIR] = LOCALEDIR,

    };

    assert(type < ARRAY_SIZE(dirs));

    const char *dir_static = dirs[type];

    assert(*dir_static != '\0');

    /* Look for common static prefix. */

    size_t prefix_len = 0;

    while (prefix_len < strlen(LIBDIR)

        && LIBDIR[prefix_len] == dir_static[prefix_len])

        prefix_len++;

    /* Check that suffix matches between static and dynamic libdir paths. */

    char *filepath = NULL;

    size_t suffix_len = strlen(LIBDIR) - prefix_len;

    size_t libdir_len = strlen(libdir);

    if (suffix_len > libdir_len

     || memcmp(&LIBDIR[prefix_len], libdir + (libdir_len - suffix_len),

               suffix_len)) {

        suffix_len = libdir_len;

        prefix_len = 0;

    }

    /* Graft non-common static suffix to dynamically computed common prefix. */

    const char *fmt = (filename != NULL) ? "%.*s%s/%s" : "%.*s%s";

    if (unlikely(asprintf(&filepath, fmt, (int)(libdir_len - suffix_len),

                          libdir, dir_static + prefix_len, filename) == -1))

        filepath = NULL;

    free(libdir);

    return filepath;

}

static char *config_GetHomeDir (void)

{

    /* 1/ Try $HOME  */

    const char *home = getenv ("HOME");

    if (home != NULL)

        return strdup (home);

#if defined(HAVE_GETPWUID_R)

    /* 2/ Try /etc/passwd */

    long max = sysconf (_SC_GETPW_R_SIZE_MAX);

    if (max != -1)

    {

        char buf[max];

        struct passwd pwbuf, *pw;

        if (getpwuid_r (getuid (), &pwbuf, buf, sizeof (buf), &pw) == 0

          && pw != NULL)

            return strdup (pw->pw_dir);

    }

#endif

    return NULL;

}

static char *config_GetAppDir (const char *xdg_name, const char *xdg_default)

{

    char *psz_dir;

    char var[sizeof ("XDG__HOME") + strlen (xdg_name)];

    /* XDG Base Directory Specification - Version 0.6 */

    snprintf (var, sizeof (var), "XDG_%s_HOME", xdg_name);

    const char *home = getenv (var);

    if (home != NULL)

    {

        if (asprintf (&psz_dir, "%s/vlc", home) == -1)

            psz_dir = NULL;

        return psz_dir;

    }

    char *psz_home = config_GetHomeDir ();

    if( psz_home == NULL

     || asprintf( &psz_dir, "%s/%s/vlc", psz_home, xdg_default ) == -1 )

        psz_dir = NULL;

    free (psz_home);

    return psz_dir;

}

static char *config_GetTypeDir (const char *xdg_name)

{

    const size_t namelen = strlen (xdg_name);

    const char *home = getenv ("HOME");

    const char *dir = getenv ("XDG_CONFIG_HOME");

    const char *file = "user-dirs.dirs";

    if (home == NULL)

        return NULL;

    if (dir == NULL)

    {

        dir = home;

        file = ".config/user-dirs.dirs";

    }

    char *path;

    if (asprintf (&path, "%s/%s", dir, file) == -1)

        return NULL;

    FILE *stream = fopen (path, "rte");

    free (path);

    path = NULL;

    if (stream != NULL)

    {

        char *linebuf = NULL;

        size_t linelen = 0;

        while (getline (&linebuf, &linelen, stream) != -1)

        {

            char *ptr = linebuf;

            ptr += strspn (ptr, " \t"); /* Skip whites */

            if (strncmp (ptr, "XDG_", 4))

                continue;

            ptr += 4; /* Skip XDG_ */

            if (strncmp (ptr, xdg_name, namelen))

                continue;

            ptr += namelen; /* Skip XDG type name */

            if (strncmp (ptr, "_DIR", 4))

                continue;

            ptr += 4; /* Skip _DIR */

            ptr += strspn (ptr, " \t"); /* Skip whites */

            if (*ptr != '=')

                continue;

            ptr++; /* Skip equality sign */

            ptr += strspn (ptr, " \t"); /* Skip whites */

            if (*ptr != '"')

                continue;

            ptr++; /* Skip quote */

            linelen -= ptr - linebuf;

            char *out;

            if (strncmp (ptr, "$HOME", 5))

            {

                path = malloc (linelen);

                if (path == NULL)

                    continue;

                out = path;

            }

            else

            {   /* Prefix with $HOME */

                const size_t homelen = strlen (home);

                ptr += 5;

                path = malloc (homelen + linelen - 5);

                if (path == NULL)

                    continue;

                memcpy (path, home, homelen);

                out = path + homelen;

            }

            while (*ptr != '"')

            {

                if (*ptr == '\\')

                    ptr++;

                if (*ptr == '\0')

                {

                    free (path);

                    path = NULL;

                    break;

                }

                *(out++) = *(ptr++);

            }

            if (path != NULL)

                *out = '\0';

            break;

        }

        free (linebuf);

        fclose (stream);

    }

    /* Default! */

    if (path == NULL)

    {

        if (strcmp (xdg_name, "DESKTOP") == 0)

        {

            if (asprintf (&path, "%s/Desktop", home) == -1)

                return NULL;

        }

        else

            path = strdup (home);

    }

    return path;

}

char *platform_GetUserDir (vlc_userdir_t type)

{

    switch (type)

    {

        case VLC_HOME_DIR:

            break;

        case VLC_CONFIG_DIR:

            return config_GetAppDir ("CONFIG", ".config");

        case VLC_USERDATA_DIR:

            return config_GetAppDir ("DATA", ".local/share");

        case VLC_CACHE_DIR:

            return config_GetAppDir ("CACHE", ".cache");

        case VLC_DESKTOP_DIR:

            return config_GetTypeDir ("DESKTOP");

        case VLC_DOWNLOAD_DIR:

            return config_GetTypeDir ("DOWNLOAD");

        case VLC_TEMPLATES_DIR:

            return config_GetTypeDir ("TEMPLATES");

        case VLC_PUBLICSHARE_DIR:

            return config_GetTypeDir ("PUBLICSHARE");

        case VLC_DOCUMENTS_DIR:

            return config_GetTypeDir ("DOCUMENTS");

        case VLC_MUSIC_DIR:

            return config_GetTypeDir ("MUSIC");

        case VLC_SNAPSHOTS_DIR:

        case VLC_PICTURES_DIR:

            return config_GetTypeDir ("PICTURES");

        case VLC_VIDEOS_DIR:

            return config_GetTypeDir ("VIDEOS");

    }

    return config_GetHomeDir ();

}