// Copyright (C) 2015-2017 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <unistd.h>
#include <thread>
#include <condition_variable>
#include <mutex>
#include <iostream>

#include <vsomeip/vsomeip.hpp>
#include <vsomeip/internal/logger.hpp>

#ifdef USE_DLT
#include <dlt/dlt.h>

#endif

static std::shared_ptr<vsomeip::application> its_application;

#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
static vsomeip::routing_state_e routing_state = vsomeip::routing_state_e::RS_RUNNING;
static bool stop_application = false;
static bool stop_sighandler = false;
static std::condition_variable_any sighandler_condition;
static std::recursive_mutex sighandler_mutex;
#endif

#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
/*
 * Handle signal to stop the daemon
 */
void routingmanagerd_stop(int _signal) {
    // Do not log messages in signal handler as this can cause deadlock in boost logger
    switch (_signal) {
    case SIGINT:
    case SIGTERM:
        stop_application = true;
        break;

    case SIGUSR1:
        routing_state = vsomeip::routing_state_e::RS_SUSPENDED;
        break;

    case SIGUSR2:
        routing_state = vsomeip::routing_state_e::RS_RESUMED;
        break;

    default:
        ;
    };

    std::unique_lock<std::recursive_mutex> its_lock(sighandler_mutex);
    sighandler_condition.notify_one();
}
#endif

/*
 * Create a vsomeip application object and start it.
 */
int routingmanagerd_process(bool _is_quiet) {
#ifdef USE_DLT
    if (!_is_quiet)
        DLT_REGISTER_APP(VSOMEIP_LOG_DEFAULT_APPLICATION_ID, VSOMEIP_LOG_DEFAULT_APPLICATION_NAME);
#else
    (void)_is_quiet;
#endif

    std::shared_ptr<vsomeip::runtime> its_runtime
        = vsomeip::runtime::get();

    if (!its_runtime) {
        return -1;
    }

    // Create the application object
    its_application = its_runtime->create_application("routingmanagerd");
#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
    std::thread sighandler_thread([]() {
        // Unblock signals for this thread only
        sigset_t handler_mask;
        sigemptyset(&handler_mask);
        sigaddset(&handler_mask, SIGUSR1);
        sigaddset(&handler_mask, SIGUSR2);
        sigaddset(&handler_mask, SIGTERM);
        sigaddset(&handler_mask, SIGINT);
        sigaddset(&handler_mask, SIGSEGV);
        sigaddset(&handler_mask, SIGABRT);
        pthread_sigmask(SIG_UNBLOCK, &handler_mask, NULL);

        // Handle the following signals
        signal(SIGINT, routingmanagerd_stop);
        signal(SIGTERM, routingmanagerd_stop);
        signal(SIGUSR1, routingmanagerd_stop);
        signal(SIGUSR2, routingmanagerd_stop);

        while (!stop_sighandler) {
            std::unique_lock<std::recursive_mutex> its_lock(sighandler_mutex);
            sighandler_condition.wait(its_lock);
            if (stop_application) {
                its_application->stop();
                return;
            } else if (routing_state == vsomeip::routing_state_e::RS_RESUMED ||
                    routing_state == vsomeip::routing_state_e::RS_SUSPENDED){
                VSOMEIP_INFO << "Received signal for setting routing_state to: 0x"
                       << std::hex << static_cast<int>(routing_state );
                its_application->set_routing_state(routing_state);
            }
        }
    });
#endif
    if (its_application->init()) {
        if (its_application->is_routing()) {
            its_application->start();
#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
            sighandler_thread.join();
#endif
            return 0;
        }
        VSOMEIP_ERROR << "routingmanagerd has not been configured as routing - abort";
    }
#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
    std::unique_lock<std::recursive_mutex> its_lock(sighandler_mutex);
    stop_sighandler = true;
    sighandler_condition.notify_one();
    sighandler_thread.join();
#endif
    return -1;
}

/*
 * Parse command line options
 * -h | --help          print usage information
 * -d | --daemonize     start background processing by forking the process
 * -q | --quiet         do _not_ use dlt logging
 *
 * and start processing.
 */
int main(int argc, char **argv) {
#ifndef VSOMEIP_ENABLE_SIGNAL_HANDLING
    // Block all signals
    sigset_t mask;
    sigfillset(&mask);
    sigprocmask(SIG_SETMASK, &mask, NULL);
#endif
    bool must_daemonize(false);
    bool is_quiet(false);
    if (argc > 1) {
        for (int i = 0; i < argc; i++) {
            std::string its_argument(argv[i]);
            if (its_argument == "-d" || its_argument == "--daemonize") {
                must_daemonize = true;
            } else if (its_argument == "-q" || its_argument == "--quiet") {
                is_quiet = true;
            } else if (its_argument == "-h" || its_argument == "--help") {
                std::cout << "usage: "
                        << argv[0] << " [-h|--help][-d|--daemonize][-q|--quiet]"
                        << std::endl;
                return 0;
            }
        }
    }

    /* Fork the process if processing shall be done in the background */
    if (must_daemonize) {
        pid_t its_process, its_signature;

        its_process = fork();

        if (its_process < 0) {
            return EXIT_FAILURE;
        }

        if (its_process > 0) {
            return EXIT_SUCCESS;
        }

        umask(0111);

        its_signature = setsid();
        if (its_signature < 0) {
            return EXIT_FAILURE;
        }
    }

    return routingmanagerd_process(is_quiet);
}