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

 * help.c: command line help

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

 * Copyright (C) 1998-2011 VLC authors and VideoLAN

 *

 * 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 <stdatomic.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <wchar.h>

#include <wctype.h>

#include <limits.h>

#include <float.h>

#include <vlc_common.h>

#include <vlc_modules.h>

#include <vlc_plugin.h>

#include <vlc_charset.h>

#include "ansi_term.h"

#include "modules/modules.h"

#include "config/configuration.h"

#include "../libvlc.h"

#if defined( _WIN32 )

# define wcwidth(cp) ((void)(cp), 1) /* LOL */

#endif

#include <unistd.h>

#if defined( _WIN32 )

# if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)

#  define HAVE_VLC_SHOWCONSOLE

# endif

#endif

#ifdef HAVE_VLC_SHOWCONSOLE

static void ShowConsole (void);

static void PauseConsole (void);

#else

# define ShowConsole() (void)0

# define PauseConsole() (void)0

#endif

static void Help (libvlc_int_t *, const char *);

static void Usage (libvlc_int_t *, const char *);

static void Version (void);

static void ListModules (libvlc_int_t *, bool);

/**

 * Returns the console width or a best guess.

 */

static unsigned ConsoleWidth(void)

{

#ifdef TIOCGWINSZ

    struct winsize ws;

    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0)

        return ws.ws_col;

#endif

#ifdef WIOCGETD

    struct uwdata uw;

    if (ioctl(STDOUT_FILENO, WIOCGETD, &uw) == 0)

        return uw.uw_height / uw.uw_vs;

#endif

#if defined (_WIN32)

#if NTDDI_VERSION >= NTDDI_WIN10_RS1 || WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)

    CONSOLE_SCREEN_BUFFER_INFO buf;

    if (GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &buf))

        return buf.dwSize.X;

#endif

#endif

    return 80;

}

/**

 * Checks for help command line options such as --help or --version.

 * If one is found, print the corresponding text.

 * \return true if a command line options caused some help message to be

 * printed, false otherwise.

 */

bool config_PrintHelp (libvlc_int_t *obj)

{

    char *str;

    /* Check for version option */

    if (var_InheritBool (obj, "version"))

    {

        Version();

        return true;

    }

    /* Check for help on modules */

    str = var_InheritString (obj, "module");

    if (str != NULL)

    {

        Help (obj, str);

        free (str);

        return true;

    }

    /* Check for full help option */

    if (var_InheritBool (obj, "full-help"))

    {

        var_Create (obj, "help-verbose", VLC_VAR_BOOL);

        var_SetBool (obj, "help-verbose", true);

        Help (obj, "full-help");

        return true;

    }

    /* Check for long help option */

    if (var_InheritBool (obj, "longhelp"))

    {

        Help (obj, "longhelp");

        return true;

    }

    /* Check for short help option */

    if (var_InheritBool (obj, "help"))

    {

        Help (obj, "help");

        return true;

    }

    if (var_InheritBool (obj, "list-verbose"))

    {

        ListModules (obj, true);

        return true;

    }

    /* Check for module list option */

    if (var_InheritBool (obj, "list"))

    {

        ListModules (obj, false );

        return true;

    }

    return false;

}

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

 * Help: print program help

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

 * Print a short inline help. Message interface is initialized at this stage.

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

static inline void print_help_on_full_help( void )

{

    putchar('\n');

    puts(_("To get exhaustive help, use '-H'."));

}

static const char vlc_usage[] = N_(

  "Usage: %s [options] [stream] ...\n"

  "You can specify multiple streams on the commandline.\n"

  "They will be enqueued in the playlist.\n"

  "The first item specified will be played first.\n"

  "\n"

  "Options-styles:\n"

  "  --option  A global option that is set for the duration of the program.\n"

  "   -option  A single letter version of a global --option.\n"

  "   :option  An option that only applies to the stream directly before it\n"

  "            and that overrides previous settings.\n"

  "\n"

  "Stream MRL syntax:\n"

  "  [[access][/demux]://]URL[#[title][:chapter][-[title][:chapter]]]\n"

  "  [:option=value ...]\n"

  "\n"

  "  Many of the global --options can also be used as MRL specific :options.\n"

  "  Multiple :option=value pairs can be specified.\n"

  "\n"

  "URL syntax:\n"

  "  file:///path/file              Plain media file\n"

  "  http://host[:port]/file        HTTP URL\n"

  "  ftp://host[:port]/file         FTP URL\n"

  "  mms://host[:port]/file         MMS URL\n"

  "  screen://                      Screen capture\n"

  "  dvd://[device]                 DVD device\n"

  "  vcd://[device]                 VCD device\n"

  "  cdda://[device]                Audio CD device\n"

  "  udp://[[<source address>]@[<bind address>][:<bind port>]]\n"

  "                                 UDP stream sent by a streaming server\n"

  "  vlc://pause:<seconds>          Pause the playlist for a certain time\n"

  "  vlc://quit                     Special item to quit VLC\n"

  "\n");

static void Help (libvlc_int_t *p_this, char const *psz_help_name)

{

    ShowConsole();

    if( psz_help_name && !strcmp( psz_help_name, "help" ) )

    {

        printf(_(vlc_usage), "vlc");

        Usage( p_this, "=core" );

        print_help_on_full_help();

    }

    else if( psz_help_name && !strcmp( psz_help_name, "longhelp" ) )

    {

        printf(_(vlc_usage), "vlc");

        Usage( p_this, NULL );

        print_help_on_full_help();

    }

    else if( psz_help_name && !strcmp( psz_help_name, "full-help" ) )

    {

        printf(_(vlc_usage), "vlc");

        Usage( p_this, NULL );

    }

    else if( psz_help_name )

    {

        Usage( p_this, psz_help_name );

    }

    PauseConsole();

}

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

 * Usage: print module usage

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

 * Print a short inline help. Message interface is initialized at this stage.

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

#   define LINE_START      8

#   define PADDING_SPACES 25

static void print_section(const module_t *m, const module_config_t **sect,

                          bool color, bool desc)

{

    const module_config_t *item = *sect;

    if (item == NULL)

        return;

    *sect = NULL;

    printf(color ? TS_RED_BOLD "   %s:\n" TS_RESET : "   %s:\n",

           module_gettext(m, item->psz_text));

    if (desc && item->psz_longtext != NULL)

        printf(color ? TS_MAGENTA_BOLD "   %s\n" TS_RESET : "   %s\n",

               module_gettext(m, item->psz_longtext));

}

static void print_desc(const char *str, unsigned margin, bool color)

{

    unsigned width = ConsoleWidth() - margin;

    if (color)

        fputs(TS_BLUE_BOLD, stdout);

    const char *word = str;

    size_t wordlen = 0;

    int wordwidth = 0;

    unsigned offset = 0;

    bool newline = true;

    while (str[0])

    {

        uint32_t cp;

        ssize_t charlen = vlc_towc(str, &cp);

        if (unlikely(charlen == -1))

            break;

        int charwidth = wcwidth(cp);

        if (charwidth < 0)

            charwidth = 0;

        str += charlen;

        if (iswspace(cp))

        {

            if (!newline)

            {

                putchar(' '); /* insert space */

                charwidth = 1;

            }

            fwrite(word, 1, wordlen, stdout); /* write complete word */

            word = str;

            wordlen = 0;

            wordwidth = 0;

            newline = false;

        }

        else

        {

            wordlen += charlen;

            wordwidth += charwidth;

        }

        offset += charwidth;

        if (offset >= width)

        {

            if (newline)

            {   /* overflow (word wider than line) */

                fwrite(word, 1, wordlen - charlen, stdout);

                word = str - charlen;

                wordlen = charlen;

                wordwidth = charwidth;

            }

            printf("\n%*s", margin, ""); /* new line */

            offset = wordwidth;

            newline = true;

        }

    }

    if (!newline)

        putchar(' ');

    printf(color ? "%s\n" TS_RESET : "%s\n", word);

}

static int vlc_swidth(const char *str)

{

    for (int total = 0;;)

    {

        uint32_t cp;

        ssize_t charlen = vlc_towc(str, &cp);

        if (charlen == 0)

            return total;

        if (charlen == -1)

            return -1;

        str += charlen;

        int w = wcwidth(cp);

        if (w == -1)

            return -1;

        total += w;

    }

}

static void print_item(const module_t *m, const struct vlc_param *param,

                       const module_config_t **section, bool color, bool desc)

{

    const module_config_t *item = &param->item;

#ifndef _WIN32

# define OPTION_VALUE_SEP " "

#else

# define OPTION_VALUE_SEP "="

#endif

    const char *bra = OPTION_VALUE_SEP "<", *type, *ket = ">";

    const char *prefix = NULL, *suffix = NULL;

    char *typebuf = NULL;

    switch (CONFIG_CLASS(item->i_type))

    {

        case 0: // hint class

            switch (item->i_type)

            {

                case CONFIG_HINT_CATEGORY:

                    printf(color ? TS_GREEN_BOLD "\n %s\n" TS_RESET : "\n %s\n",

                           module_gettext(m, item->psz_text));

                    if (desc && item->psz_longtext != NULL)

                        printf(color ? TS_CYAN_BOLD " %s\n" TS_RESET : " %s\n",

                               module_gettext(m, item->psz_longtext));

                    break;

                case CONFIG_SUBCATEGORY:

                    /* We ignore these here, using 'hints' instead */

                    break;

                case CONFIG_SECTION:

                    *section = item;

                    break;

            }

            return;

        case CONFIG_ITEM_STRING:

        {

            type = _("string");

            char **ppsz_values, **ppsz_texts;

            ssize_t i_count = config_GetPszChoices(item->psz_name, &ppsz_values, &ppsz_texts);

            if (i_count > 0)

            {

                size_t len = 0;

                for (size_t i = 0; i < (size_t)i_count; i++)

                    len += strlen(ppsz_values[i]) + 1;

                typebuf = malloc(len);

                if (typebuf == NULL)

                    goto end_string;

                bra = OPTION_VALUE_SEP "{";

                type = typebuf;

                ket = "}";

                *typebuf = 0;

                for (size_t i = 0; i < (size_t)i_count; i++)

                {

                    if (i > 0)

                        strcat(typebuf, ",");

                    strcat(typebuf, ppsz_values[i]);

                }

            end_string:

                for (size_t i = 0; i < (size_t)i_count; i++)

                {

                    free(ppsz_values[i]);

                    free(ppsz_texts[i]);

                }

                free(ppsz_values);

                free(ppsz_texts);

            }

            break;

        }

        case CONFIG_ITEM_INTEGER:

        {

            type = _("integer");

            int64_t *pi_values;

            char **ppsz_texts;

            ssize_t i_count = config_GetIntChoices(item->psz_name, &pi_values, &ppsz_texts);

            if (i_count > 0)

            {

                size_t len = 0;

                for (size_t i = 0; i < (size_t)i_count; i++)

                    len += strlen(ppsz_texts[i])

                           + 4 * sizeof (int64_t) + 5;

                typebuf = malloc(len);

                if (typebuf == NULL)

                    goto end_integer;

                bra = OPTION_VALUE_SEP "{";

                type = typebuf;

                ket = "}";

                *typebuf = 0;

                for (size_t i = 0; i < (size_t)i_count; i++)

                {

                    if (i != 0)

                        strcat(typebuf, ", ");

                    sprintf(typebuf + strlen(typebuf), "%"PRIi64" (%s)",

                            pi_values[i],

                            ppsz_texts[i]);

                }

            end_integer:

                for (size_t i = 0; i < (size_t)i_count; i++)

                    free(ppsz_texts[i]);

                free(pi_values);

                free(ppsz_texts);

            }

            else if (item->min.i != INT64_MIN || item->max.i != INT64_MAX )

            {

                if (asprintf(&typebuf, "%s [%"PRId64" .. %"PRId64"]",

                             type, item->min.i, item->max.i) >= 0)

                    type = typebuf;

                else

                    typebuf = NULL;

            }

            break;

        }

        case CONFIG_ITEM_FLOAT:

            type = _("float");

            if (item->min.f != -FLT_MAX || item->max.f != FLT_MAX)

            {

                if (asprintf(&typebuf, "%s [%f .. %f]", type,

                             item->min.f, item->max.f) >= 0)

                    type = typebuf;

                else

                    typebuf = NULL;

            }

            break;

        case CONFIG_ITEM_BOOL:

            bra = type = ket = "";

            prefix = ", --no-";

            suffix = item->orig.i ? _("(default enabled)")

                                  : _("(default disabled)");

            break;

       default:

            return;

    }

    print_section(m, section, color, desc);

    /* Add short option if any */

    char shortopt[4];

    if (param->shortname != '\0')

        sprintf(shortopt, "-%c,", param->shortname);

    else

        strcpy(shortopt, "   ");

    if (CONFIG_CLASS(item->i_type) == CONFIG_ITEM_BOOL)

        printf(color ? TS_BOLD "  %s --%s"      "%s%s%s%s%s " TS_RESET

                     : "  %s --%s%s%s%s%s%s ", shortopt, item->psz_name,

               prefix, item->psz_name, bra, type, ket);

    else

        printf(color ? TS_BOLD "  %s --%s" TS_YELLOW_BOLD "%s%s%s%s%s " TS_RESET

                     : "  %s --%s%s%s%s%s%s ", shortopt, item->psz_name,

               "", "",  /* XXX */      bra, type, ket);

    /* Wrap description */

    int offset = PADDING_SPACES - strlen(item->psz_name)

               - strlen(bra) - vlc_swidth(type) - strlen(ket) - 1;

    if (CONFIG_CLASS(item->i_type) == CONFIG_ITEM_BOOL)

        offset -= strlen(item->psz_name) + vlc_swidth(prefix);

    if (offset < 0)

    {

        putchar('\n');

        offset = PADDING_SPACES + LINE_START;

    }

    printf("%*s", offset, "");

    print_desc(module_gettext(m, item->psz_text),

               PADDING_SPACES + LINE_START, color);

    if (suffix != NULL)

    {

        printf("%*s", PADDING_SPACES + LINE_START, "");

        print_desc(suffix, PADDING_SPACES + LINE_START, color);

    }

    if (desc && (item->psz_longtext != NULL && item->psz_longtext[0]))

    {   /* Wrap long description */

        printf("%*s", LINE_START + 2, "");

        print_desc(module_gettext(m, item->psz_longtext),

                   LINE_START + 2, false);

    }

    free(typebuf);

}

static bool module_match(const module_t *m, const char *pattern, bool strict)

{

    if (pattern == NULL)

        return true;

    const char *objname = module_get_object(m);

    if (strict ? (strcmp(objname, pattern) == 0)

               : (strstr(objname, pattern) != NULL))

        return true;

    for (unsigned i = 0; i < m->i_shortcuts; i++)

    {

        const char *shortcut = m->pp_shortcuts[i];

        if (strict ? (strcmp(shortcut, pattern) == 0)

                   : (strstr(shortcut, pattern) != NULL))

            return true;

    }

    return false;

}

static bool plugin_show(const vlc_plugin_t *plugin)

{

    for (size_t i = 0; i < plugin->conf.size; i++)

    {

        const struct vlc_param *param = plugin->conf.params + i;

        const module_config_t *item = &param->item;

        if (!CONFIG_ITEM(item->i_type))

            continue;

        if (param->obsolete)

            continue;

        return true;

    }

    return false;

}

static void Usage (libvlc_int_t *p_this, char const *psz_search)

{

    bool found = false;

    bool strict = false;

    if (psz_search != NULL && psz_search[0] == '=')

    {

        strict = true;

        psz_search++;

    }

    bool color = false;

#ifdef HAVE_ISATTY

    if (isatty(STDOUT_FILENO))

        color = var_InheritBool(p_this, "color");

#endif

    const bool desc = var_InheritBool(p_this, "help-verbose");

    /* Enumerate the config for each module */

    for (const vlc_plugin_t *p = vlc_plugins; p != NULL; p = p->next)

    {

        const module_t *m = p->module;

        const module_config_t *section = NULL;

        const char *objname = module_get_object(m);

        if (psz_search == NULL && p->conf.count == 0)

            continue; /* Ignore modules without config options */

        if (!module_match(m, psz_search, strict))

            continue;

        found = true;

        if (psz_search == NULL && !plugin_show(p))

            continue;

        /* Print name of module */

        printf(color ? "\n " TS_GREEN_BOLD "%s" TS_RESET " (%s)\n" : "\n %s (%s)\n",

               module_gettext(m, m->psz_longname), objname);

        if (m->psz_help != NULL)

            printf(color ? TS_CYAN_BOLD" %s\n" TS_RESET : " %s\n",

                   module_gettext(m, m->psz_help));

        if (psz_search != NULL && p->conf.count == 0)

            printf("  %s\n", _("This module has no options."));

        /* Print module options */

        for (size_t j = 0; j < p->conf.size; j++)

        {

            const struct vlc_param *param = p->conf.params + j;

            if (param->obsolete)

                continue; /* Skip removed options */

            print_item(m, param, &section, color, desc);

        }

    }

    if (!found)

        printf(color ? "\n" TS_BOLD "%s" TS_RESET "\n" : "\n%s\n",

               _("No matching module found. Use --list or "

                 "--list-verbose to list available modules."));

}

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

 * ListModules: list the available modules with their description

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

 * Print a list of all available modules (builtins and plugins) and a short

 * description for each one.

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

static void ListModules (libvlc_int_t *p_this, bool b_verbose)

{

    bool color = false;

    ShowConsole();

#ifdef HAVE_ISATTY

    if (isatty(STDOUT_FILENO))

        color = var_InheritBool(p_this, "color");

#else

    (void) p_this;

#endif

    /* List all modules */

    size_t count;

    module_t **list = module_list_get (&count);

    /* Enumerate each module */

    for (size_t j = 0; j < count; j++)

    {

        module_t *p_parser = list[j];

        const char *objname = module_get_object (p_parser);

        printf(color ? TS_GREEN_BOLD "  %-22s " TS_RESET_BOLD "%s\n" TS_RESET : "  %-22s %s\n",

               objname, module_gettext(p_parser, p_parser->psz_longname));

        if( b_verbose )

        {

            const char *const *pp_shortcuts = p_parser->pp_shortcuts;

            for( unsigned i = 0; i < p_parser->i_shortcuts; i++ )

                if( strcmp( pp_shortcuts[i], objname ) )

                    printf(color ? TS_CYAN_BOLD "   s %s\n" TS_RESET : "   s %s\n",

                           pp_shortcuts[i]);

            if (p_parser->psz_capability != NULL)

                printf(color ? TS_MAGENTA_BOLD "   c %s (%d)\n" TS_RESET : "   c %s (%d)\n",

                       p_parser->psz_capability, p_parser->i_score);

        }

    }

    module_list_free (list);

    PauseConsole();

}

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

 * Version: print complete program version

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

 * Print complete program version and build number.

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

static void Version( void )

{

    ShowConsole();

    printf(_("VLC version %s (%s)\n"), VERSION_MESSAGE, psz_vlc_changeset);

    printf(_("Compiled by %s on %s (%s)\n"), VLC_CompileBy(),

           VLC_CompileHost(), __DATE__" "__TIME__ );

    printf(_("Compiler: %s\n"), VLC_Compiler());

    fputs(LICENSE_MSG, stdout);

    PauseConsole();

}

#ifdef HAVE_VLC_SHOWCONSOLE

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

 * ShowConsole: On Win32, create an output console for debug messages

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

 * This function is useful only on Win32.

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

static void ShowConsole( void )

{

    if( getenv( "PWD" ) ) return; /* Cygwin shell or Wine */

    if( !AllocConsole() ) return;

    /* Use the ANSI code page (e.g. Windows-1252) as expected by the LibVLC

     * Unicode/locale subsystem. By default, we have the obsolecent OEM code

     * page (e.g. CP437 or CP850). */

    SetConsoleOutputCP (GetACP ());

    SetConsoleTitle (TEXT("VLC media player version ") TEXT(PACKAGE_VERSION));

    freopen( "CONOUT$", "w", stderr );

    freopen( "CONIN$", "r", stdin );

    if( freopen( "vlc-help.txt", "wt", stdout ) != NULL )

    {

        fputs( "\xEF\xBB\xBF", stdout );

        fprintf( stderr, _("\nDumped content to vlc-help.txt file.\n") );

    }

    else

        freopen( "CONOUT$", "w", stdout );

}

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

 * PauseConsole: On Win32, wait for a key press before closing the console

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

 * This function is useful only on Win32.

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

static void PauseConsole( void )

{

    if( getenv( "PWD" ) ) return; /* Cygwin shell or Wine */

    utf8_fprintf( stderr, _("\nPress the RETURN key to continue...\n") );

    getchar();

    fclose( stdout );

}

#endif