#include <signal.h>
#include <sys/signalfd.h>
#include <unistd.h>

#include <QCommandLineOption>
#include <QCommandLineParser>
#include <QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QSocketNotifier>

#include "CloudConnectController.h"

#define log qDebug().noquote()

int main(int argc, char *argv[])
{
    // Block SIGINT and SIGTERM from normal delivery
    sigset_t mask;
    sigemptyset(&mask);
    sigaddset(&mask, SIGINT);
    sigaddset(&mask, SIGTERM);
    sigprocmask(SIG_BLOCK, &mask, nullptr);

    const int sfd = signalfd(-1, &mask, SFD_CLOEXEC);
    if (sfd == -1) {
        qCritical("Failed to create signalfd");
        return 1;
    }

    QCoreApplication app(argc, argv);
    app.setApplicationName("CloudConnect");
    app.setApplicationVersion("1.0");

    // notifier runs on the main thread inside the event loop
    QSocketNotifier notifier(sfd, QSocketNotifier::Read);
    QObject::connect(&notifier, &QSocketNotifier::activated, [&](int fd) {
        struct signalfd_siginfo info{};
        // A short read leaves info zeroed; don't quit on a phantom signal.
        const ssize_t bytes = read(fd, &info, sizeof(info));
        if (bytes != sizeof(info)) {
            qWarning("Short read from signalfd (%zd bytes); ignoring", bytes);
            return;
        }
        if (info.ssi_signo == SIGINT) {
            log << "Application terminated by SIGINT";
        }
        else if (info.ssi_signo == SIGTERM) {
            log << "Application terminated by SIGTERM";
        }
        app.quit();
    });

    QCommandLineParser parser;
    parser.setApplicationDescription("CloudConnect application");
    parser.addHelpOption();
    parser.addVersionOption();

    QCommandLineOption configOption(
        {"c", "config"}, "Path to the configuration INI file.", "config",
        QDir(app.applicationDirPath()).filePath("/home/leahi/Public/leahi-realtime-cdt/CloudConnect/config/CloudConnect.ini")
    );
    QCommandLineOption msgHandlingOption(
        {"m", "msg_handling"}, "Path to the message handling INI file.", "msg_handling",
        QDir(app.applicationDirPath()).filePath("/home/leahi/Public/leahi-realtime-cdt/CloudConnect/config/LeahiMsgHandling.ini")
    );
    parser.addOption(configOption);
    parser.addOption(msgHandlingOption);
    parser.process(app);

    QThread controllerThread;
    CloudConnectController ccController(parser.value(configOption), parser.value(msgHandlingOption));

    // Bind on the controller thread: QLocalServer's socket engine belongs to the
    // thread that calls listen(), and accepted sockets are parented under it.
    QObject::connect(&controllerThread, &QThread::started, &ccController,
        [&ccController, &app]() {
            if (!ccController.listenForApp()) {
                qCritical() << "Failed to bind the app socket; shutting down";
                QMetaObject::invokeMethod(&app, [&app]() { app.exit(1); }, Qt::QueuedConnection);
                return;
            }
            // QTcpSocket belongs to the thread that constructs it.
            // Broker connect is async, so false = config failure, not unreachable.
            if (!ccController.connectToCloud()) {
                qCritical() << "Failed to start the MQTT connection; shutting down";
                QMetaObject::invokeMethod(&app, [&app]() { app.exit(1); }, Qt::QueuedConnection);
                return;
            }
            // CAN last; frames arriving before MQTT CONNACK are still dropped.
            if (!ccController.startCan()) {
                qWarning() << "Failed to start the CAN interface; no frames will be forwarded";
            }
        }
    );

    ccController.initThread(controllerThread);

    const int rc = app.exec();

    // Stop the worker thread before the controller is destroyed at scope exit.
    controllerThread.quit();
    controllerThread.wait();

    return rc;
}