/* Test program for argp argument parser
   Copyright (C) 1997-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Written by Miles Bader <miles@gnu.ai.mit.edu>.

   The GNU C Library 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.

   The GNU C Library 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 the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <argp.h>

const char* argp_program_version = "argp-test 1.0";

struct argp_option sub_options[] = { { "subopt1", 's', 0, 0, "Nested option 1" },
                                     { "subopt2", 'S', 0, 0, "Nested option 2" },

                                     { 0, 0, 0, 0, "Some more nested options:", 10 },
                                     { "subopt3", 'p', 0, 0, "Nested option 3" },

                                     { "subopt4", 'q', 0, 0, "Nested option 4", 1 },

                                     { 0 } };

static const char sub_args_doc[] = "STRING...\n-";
static const char sub_doc[] = "\vThis is the doc string from the sub-arg-parser.";

static error_t
sub_parse_opt(int key, char* arg, struct argp_state* state)
{
    switch (key)
    {
        case ARGP_KEY_NO_ARGS:
            printf("NO SUB ARGS\n");
            break;
        case ARGP_KEY_ARG:
            printf("SUB ARG: %s\n", arg);
            break;

        case 's':
        case 'S':
        case 'p':
        case 'q':
            printf("SUB KEY %c\n", key);
            break;

        default:
            return ARGP_ERR_UNKNOWN;
    }
    return 0;
}

static char*
sub_help_filter(int key, const char* text, void* input)
{
    if (key == ARGP_KEY_HELP_EXTRA)
        return strdup("This is some extra text from the sub parser (note that it \
is preceded by a blank line).");
    else
        return (char*) text;
}

static struct argp sub_argp
    = { sub_options, sub_parse_opt, sub_args_doc, sub_doc, 0, sub_help_filter };

/* Structure used to communicate with the parsing functions.  */
struct params
{
    unsigned foonly;         /* Value parsed for foonly.  */
    unsigned foonly_default; /* Default value for it.  */
};

#define OPT_PGRP 1
#define OPT_SESS 2

struct argp_option options[]
    = { { "pid", 'p', "PID", 0, "List the process PID" },
        { "pgrp", OPT_PGRP, "PGRP", 0, "List processes in the process group PGRP" },
        { "no-parent", 'P', 0, 0, "Include processes without parents" },
        { 0, 'x', 0, OPTION_ALIAS },
        { "all-fields",
          'Q',
          0,
          0,
          "Don't elide unusable fields (normally"
          " if there's some reason ps can't"
          " print a field for any process, it's"
          " removed from the output entirely)" },
        { "reverse", 'r', 0, 0, "Reverse the order of any sort" },
        { "gratuitously-long-reverse-option", 0, 0, OPTION_ALIAS },
        { "session",
          OPT_SESS,
          "SID",
          OPTION_ARG_OPTIONAL,
          "Add the processes from the session"
          " SID (which defaults to the sid of"
          " the current process)" },

        { 0, 0, 0, 0, "Here are some more options:" },
        { "foonly", 'f', "ZOT", OPTION_ARG_OPTIONAL, "Glork a foonly" },
        { "zaza", 'z', 0, 0, "Snit a zar" },

        { 0 } };

static const char args_doc[] = "STRING";
static const char doc[] = "Test program for argp."
                          "\vThis doc string comes after the options."
                          "\nHey!  Some manual formatting!"
                          "\nThe current time is: %s";

static void
popt(int key, char* arg)
{
    char buf[12];
    if (isprint(key))
        sprintf(buf, "%c", key);
    else
        sprintf(buf, "%d", key);
    if (arg)
        printf("KEY %s: %s\n", buf, arg);
    else
        printf("KEY %s\n", buf);
}

static error_t
parse_opt(int key, char* arg, struct argp_state* state)
{
    struct params* params = state->input;

    switch (key)
    {
        case ARGP_KEY_NO_ARGS:
            printf("NO ARGS\n");
            break;

        case ARGP_KEY_ARG:
            if (state->arg_num > 0)
                return ARGP_ERR_UNKNOWN; /* Leave it for the sub-arg parser.  */
            printf("ARG: %s\n", arg);
            break;

        case 'f':
            if (arg)
                params->foonly = atoi(arg);
            else
                params->foonly = params->foonly_default;
            popt(key, arg);
            break;

        case 'p':
        case 'P':
        case OPT_PGRP:
        case 'x':
        case 'Q':
        case 'r':
        case OPT_SESS:
        case 'z':
            popt(key, arg);
            break;

        default:
            return ARGP_ERR_UNKNOWN;
    }
    return 0;
}

static char*
help_filter(int key, const char* text, void* input)
{
    char* new_text;
    struct params* params = input;

    if (key == ARGP_KEY_HELP_POST_DOC && text)
    {
        time_t now = time(0);
        asprintf(&new_text, text, ctime(&now));
    }
    else if (key == 'f')
        /* Show the default for the --foonly option.  */
        asprintf(&new_text, "%s (ZOT defaults to %x)", text, params->foonly_default);
    else
        new_text = (char*) text;

    return new_text;
}

static struct argp_child argp_children[] = { { &sub_argp }, { 0 } };
static struct argp argp = { options, parse_opt, args_doc, doc, argp_children, help_filter };

int
main(int argc, char** argv)
{
    struct params params;
    params.foonly = 0;
    params.foonly_default = random();
    argp_parse(&argp, argc, argv, 0, 0, &params);
    printf("After parsing: foonly = %x\n", params.foonly);
    return 0;
}