/* Copyright (C) 2022 The Qt Company Ltd.
 *
 * SPDX-License-Identifier: GPL-3.0-only WITH Qt-GPL-exception-1.0
*/

#include <sys/stat.h>
#include <iostream>
#include <unistd.h>
#include <csignal>
#include <cstring>

#include "licenseservice.h"
#include "version.h"

using namespace QLicenseService;

std::unique_ptr<LicenseService> service;

void signalHandler(int signal)
{
    if (!service)
        exit(signal);

    switch (signal) {
    case SIGINT:
        service->cancel();
        break;
    case SIGTERM:
        service->cancel();
        break;
    default:
        exit(signal);
    }
}

int startProcess(uint16_t tcpPort) {
    // Fire it up
    service.reset(new LicenseService(tcpPort));

    if (!(service->start() && service->waitForStarted())) {
        std::cout << "Error while starting licenser: " << service->errorString() << std::endl;
        return EXIT_FAILURE;
    }

    std::cout << "Started\n";
    std::cout << "listening..\n";

    if (!service->waitForFinished()) {
        std::cout << "Error while stopping licenser: " << service->errorString() << std::endl;
        return EXIT_FAILURE;
    }

    // Licenser runs infinitely if not interrupted
    if (service->status() != LicenseService::Status::Canceled
            && service->status() != LicenseService::Status::Finished) {
        std::cout << "Unexpected status for stopped licenser: " << service->errorString() << std::endl;
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

int main(int argc, char *argv[])
{
    signal(SIGINT, signalHandler);
    signal(SIGTERM, signalHandler);

    uint16_t tcpPort = 0;

    // Get arguments
    std::string message = "";
    bool all_ok = true;
    for (int i = 1; i < argc; i++) {
        // If command-line parameter is "--nodaemon", start right away
        // as normal CLI process (not as daemon)
        if (strcmp(argv[1], "--nodaemon") == 0)
            return startProcess(0);

        // If command-line parameter is "--version", show the version and exit.
        else if (strcmp(argv[1], "--version") == 0) {
                std::cout << "Qt License Daemon (qtlicd) v" << DAEMON_VERSION << " "
                        << COPYRIGHT_TEXT << std::endl;
                return EXIT_SUCCESS;
        }
        else if (strcmp(argv[i], "--port") == 0) {
            if (i + 1 == argc) {
                all_ok = false;
                printf("No port number given\n");
                break;
            }
            try {
                tcpPort = std::stoi(argv[i+1]);
                i++;
            }
            catch (...) {
                all_ok = false;
                printf("Invalid port - must be an integer\n");
                break;
            }
        }
        else if (strcmp(argv[i], "--help") == 0) {
            all_ok = false;
            break;
        }
        else {
            printf("Invalid argument: %s\n", argv[i]);
            all_ok = false;
            break;
        }
    }
    if (!all_ok) {
        printf("\nUsage: qtlicd [option] [value]\n");
        printf("Supported options are:\n");
        printf("  --port <port number>   : Specify TCP/IP server port. If omitted, default is used.\n");
        printf("  --nodaemon             : Run in non-daemon mode (in console like any other CLI app)\n");
        printf("  --version              : Version info\n");
        printf("  --help                 : This help\n\n");
        return EXIT_FAILURE;
    }

    printf("Starting daemon\n");

    // Fork process
    pid_t pid, sid;
    pid = fork();
    if (pid > 0) {
        return EXIT_SUCCESS;
    }
    else if (pid < 0) {
        printf("Daemon process fork failed!\n");
        return EXIT_FAILURE;
    }
    umask(0);
    sid = setsid();
    // Check session ID for the child process
    if (sid < 0)
    {
        printf("Invalid session id for a child process\n");
        return EXIT_FAILURE;
    }

    return startProcess(tcpPort);
}