/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <AK/String.h>
#include <LibCore/ProcessStatisticsReader.h>
#include <ctype.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

static void print_usage_and_exit()
{
    printf("usage: killall [-signal] process_name\n");
    exit(1);
}

static int kill_all(const String& process_name, const unsigned signum)
{
    auto processes = Core::ProcessStatisticsReader().get_all();
    if (!processes.has_value())
        return 1;

    for (auto& it : processes.value()) {
        if (it.value.name == process_name) {
            int ret = kill(it.value.pid, signum);
            if (ret < 0)
                perror("kill");
        }
    }

    return 0;
}

int main(int argc, char** argv)
{
    unsigned signum = SIGTERM;
    int name_argi = 1;

    if (argc != 2 && argc != 3)
        print_usage_and_exit();

    if (argc == 3) {
        name_argi = 2;

        if (argv[1][0] != '-')
            print_usage_and_exit();

        Optional<unsigned> number;

        if (isalpha(argv[1][1])) {
            int value = getsignalbyname(&argv[1][1]);
            if (value >= 0 && value < NSIG)
                number = value;
        }

        if (!number.has_value())
            number = String(&argv[1][1]).to_uint();

        if (!number.has_value()) {
            printf("'%s' is not a valid signal name or number\n", &argv[1][1]);
            return 2;
        }
        signum = number.value();
    }

    return kill_all(argv[name_argi], signum);
}