/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "sd-bus.h"

#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
#include "fd-util.h"
#include "format-table.h"
#include "format-util.h"
#include "main-func.h"
#include "pager.h"
#include "pretty-print.h"
#include "process-util.h"
#include "signal-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "user-util.h"
#include "util.h"

static const char* arg_what = "idle:sleep:shutdown";
static const char* arg_who = NULL;
static const char* arg_why = "Unknown reason";
static const char* arg_mode = NULL;
static PagerFlags arg_pager_flags = 0;
static bool arg_legend = true;

static enum {
        ACTION_INHIBIT,
        ACTION_LIST
} arg_action = ACTION_INHIBIT;

static int inhibit(sd_bus *bus, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
        int r;
        int fd;

        r = sd_bus_call_method(
                        bus,
                        "org.freedesktop.login1",
                        "/org/freedesktop/login1",
                        "org.freedesktop.login1.Manager",
                        "Inhibit",
                        error,
                        &reply,
                        "ssss", arg_what, arg_who, arg_why, arg_mode);
        if (r < 0)
                return r;

        r = sd_bus_message_read_basic(reply, SD_BUS_TYPE_UNIX_FD, &fd);
        if (r < 0)
                return r;

        r = fcntl(fd, F_DUPFD_CLOEXEC, 3);
        if (r < 0)
                return -errno;

        return r;
}

static int print_inhibitors(sd_bus *bus) {
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
        _cleanup_(table_unrefp) Table *table = NULL;
        int r;

        (void) pager_open(arg_pager_flags);

        r = sd_bus_call_method(
                        bus,
                        "org.freedesktop.login1",
                        "/org/freedesktop/login1",
                        "org.freedesktop.login1.Manager",
                        "ListInhibitors",
                        &error,
                        &reply,
                        "");
        if (r < 0)
                return log_error_errno(r, "Could not get active inhibitors: %s", bus_error_message(&error, r));

        table = table_new("who", "uid", "user", "pid", "comm", "what", "why", "mode");
        if (!table)
                return log_oom();

        /* If there's not enough space, shorten the "WHY" column, as it's little more than an explaining comment. */
        (void) table_set_weight(table, TABLE_HEADER_CELL(6), 20);
        (void) table_set_maximum_width(table, TABLE_HEADER_CELL(0), columns()/2);

        r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "(ssssuu)");
        if (r < 0)
                return bus_log_parse_error(r);

        for (;;) {
                _cleanup_free_ char *comm = NULL, *u = NULL;
                const char *what, *who, *why, *mode;
                uint32_t uid, pid;

                r = sd_bus_message_read(reply, "(ssssuu)", &what, &who, &why, &mode, &uid, &pid);
                if (r < 0)
                        return bus_log_parse_error(r);
                if (r == 0)
                        break;

                if (arg_mode && !streq(mode, arg_mode))
                        continue;

                (void) get_process_comm(pid, &comm);
                u = uid_to_name(uid);

                r = table_add_many(table,
                                   TABLE_STRING, who,
                                   TABLE_UID, (uid_t) uid,
                                   TABLE_STRING, strna(u),
                                   TABLE_PID, (pid_t) pid,
                                   TABLE_STRING, strna(comm),
                                   TABLE_STRING, what,
                                   TABLE_STRING, why,
                                   TABLE_STRING, mode);
                if (r < 0)
                        return table_log_add_error(r);
        }

        r = sd_bus_message_exit_container(reply);
        if (r < 0)
                return bus_log_parse_error(r);

        if (table_get_rows(table) > 1) {
                r = table_set_sort(table, (size_t) 1, (size_t) 0, (size_t) 5, (size_t) 6);
                if (r < 0)
                        return table_log_sort_error(r);

                table_set_header(table, arg_legend);

                r = table_print(table, NULL);
                if (r < 0)
                        return table_log_print_error(r);
        }

        if (arg_legend) {
                if (table_get_rows(table) > 1)
                        printf("\n%zu inhibitors listed.\n", table_get_rows(table) - 1);
                else
                        printf("No inhibitors.\n");
        }

        return 0;
}

static int help(void) {
        _cleanup_free_ char *link = NULL;
        int r;

        r = terminal_urlify_man("systemd-inhibit", "1", &link);
        if (r < 0)
                return log_oom();

        printf("%s [OPTIONS...] COMMAND ...\n"
               "\n%sExecute a process while inhibiting shutdown/sleep/idle.%s\n\n"
               "  -h --help               Show this help\n"
               "     --version            Show package version\n"
               "     --no-pager           Do not pipe output into a pager\n"
               "     --no-legend          Do not show the headers and footers\n"
               "     --what=WHAT          Operations to inhibit, colon separated list of:\n"
               "                          shutdown, sleep, idle, handle-power-key,\n"
               "                          handle-suspend-key, handle-hibernate-key,\n"
               "                          handle-lid-switch\n"
               "     --who=STRING         A descriptive string who is inhibiting\n"
               "     --why=STRING         A descriptive string why is being inhibited\n"
               "     --mode=MODE          One of block or delay\n"
               "     --list               List active inhibitors\n"
               "\nSee the %s for details.\n",
               program_invocation_short_name,
               ansi_highlight(),
               ansi_normal(),
               link);

        return 0;
}

static int parse_argv(int argc, char *argv[]) {

        enum {
                ARG_VERSION = 0x100,
                ARG_WHAT,
                ARG_WHO,
                ARG_WHY,
                ARG_MODE,
                ARG_LIST,
                ARG_NO_PAGER,
                ARG_NO_LEGEND,
        };

        static const struct option options[] = {
                { "help",         no_argument,       NULL, 'h'              },
                { "version",      no_argument,       NULL, ARG_VERSION      },
                { "what",         required_argument, NULL, ARG_WHAT         },
                { "who",          required_argument, NULL, ARG_WHO          },
                { "why",          required_argument, NULL, ARG_WHY          },
                { "mode",         required_argument, NULL, ARG_MODE         },
                { "list",         no_argument,       NULL, ARG_LIST         },
                { "no-pager",     no_argument,       NULL, ARG_NO_PAGER     },
                { "no-legend",    no_argument,       NULL, ARG_NO_LEGEND       },
                {}
        };

        int c;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "+h", options, NULL)) >= 0)

                switch (c) {

                case 'h':
                        return help();

                case ARG_VERSION:
                        return version();

                case ARG_WHAT:
                        arg_what = optarg;
                        break;

                case ARG_WHO:
                        arg_who = optarg;
                        break;

                case ARG_WHY:
                        arg_why = optarg;
                        break;

                case ARG_MODE:
                        arg_mode = optarg;
                        break;

                case ARG_LIST:
                        arg_action = ACTION_LIST;
                        break;

                case ARG_NO_PAGER:
                        arg_pager_flags |= PAGER_DISABLE;
                        break;

                case ARG_NO_LEGEND:
                        arg_legend = false;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        if (arg_action == ACTION_INHIBIT && optind == argc)
                arg_action = ACTION_LIST;

        else if (arg_action == ACTION_INHIBIT && optind >= argc)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Missing command line to execute.");

        return 1;
}

static int run(int argc, char *argv[]) {
        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
        int r;

        log_show_color(true);
        log_parse_environment();
        log_open();

        r = parse_argv(argc, argv);
        if (r <= 0)
                return r;

        r = sd_bus_default_system(&bus);
        if (r < 0)
                return bus_log_connect_error(r);

        if (arg_action == ACTION_LIST)
                return print_inhibitors(bus);
        else {
                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
                _cleanup_strv_free_ char **arguments = NULL;
                _cleanup_free_ char *w = NULL;
                _cleanup_close_ int fd = -1;
                pid_t pid;

                /* Ignore SIGINT and allow the forked process to receive it */
                (void) ignore_signals(SIGINT);

                if (!arg_who) {
                        w = strv_join(argv + optind, " ");
                        if (!w)
                                return log_oom();

                        arg_who = w;
                }

                if (!arg_mode)
                        arg_mode = "block";

                fd = inhibit(bus, &error);
                if (fd < 0)
                        return log_error_errno(fd, "Failed to inhibit: %s", bus_error_message(&error, fd));

                arguments = strv_copy(argv + optind);
                if (!arguments)
                        return log_oom();

                r = safe_fork("(inhibit)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
                if (r < 0)
                        return r;
                if (r == 0) {
                        /* Child */
                        execvp(arguments[0], arguments);
                        log_open();
                        log_error_errno(errno, "Failed to execute %s: %m", argv[optind]);
                        _exit(EXIT_FAILURE);
                }

                return wait_for_terminate_and_check(argv[optind], pid, WAIT_LOG);
        }
}

DEFINE_MAIN_FUNCTION_WITH_POSITIVE_FAILURE(run);