#include <QApplication>
#include <QCoreApplication>
#include <QDebug>
#include <QMessageBox>
#include <QProcess>
#include <QProgressDialog>
#include <QInputDialog>
#include <QLineEdit>
#include <QTranslator>
#include "UpdateLogic.h"
#include "../Common/ConfigHelper.h"
#include "../Common/PolicyHelper.h"
#include "../Common/LocalStateHelper.h"
#include "../Common/TicketHelper.h"
#include "../Common/DeviceIdentityHelper.h"
#include <QFile>
#include <QFileDialog>
#include <QDir>

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QApplication::setApplicationName("Marsco Launcher");
    QTranslator translator;
    if (translator.load(":/i18n/update-client_zh_CN.qm"))
        app.installTranslator(&translator);

    const int elevatedWriteExitCode = ConfigHelper::runElevatedWriteCommandIfRequested();
    if (elevatedWriteExitCode >= 0)
        return elevatedWriteExitCode;

    QProgressDialog progress(QCoreApplication::translate("Launcher", "Checking for software updates..."), QString(), 0, 0);
    progress.setWindowTitle(QCoreApplication::translate("Launcher", "Marsco Launcher"));
    progress.setCancelButton(nullptr);
    progress.setWindowModality(Qt::ApplicationModal);
    progress.setMinimumDuration(0);
    progress.setAutoClose(false);
    progress.show();
    QApplication::processEvents();

    const QString appDir = QApplication::applicationDirPath();
    ConfigHelper& config = ConfigHelper::instance();
    const auto isLicenseError = [](const QString& errorText) {
        const QString text = errorText.toLower();
        return text.contains("license")
            || text.contains("authorization")
            || text.contains("expired")
            || text.contains("device limit")
            || text.contains("bound to another license");
    };
    const auto clearDeviceCredential = [&]() {
        ConfigHelper::removeFileWithElevationIfNeeded(QDir(appDir).filePath("config/client_identity.dat"));
        config.setValue("Update", "device_id", QString());
    };
    QString licenseKey = config.getValue("License", "license_key").trimmed();
    auto promptAndSaveLicense = [&](const QString& reason) -> QString {
        QString promptReason = reason;
        while (true) {
            progress.close();
            bool accepted = false;
            const QString appName = config.getValue("App", "app_name").trimmed();
            const QString prompt = promptReason.trimmed().isEmpty()
                ? QCoreApplication::translate("Launcher", "Please enter the License for %1:")
                    .arg(appName.isEmpty() ? QCoreApplication::translate("Launcher", "the application") : appName)
                : QCoreApplication::translate("Launcher", "%1\n\nPlease enter a new License for %2:")
                    .arg(promptReason, appName.isEmpty() ? QCoreApplication::translate("Launcher", "the application") : appName);
            licenseKey = QInputDialog::getText(
                nullptr,
                QCoreApplication::translate("Launcher", "Enter License"),
                prompt,
                QLineEdit::Normal,
                QString(),
                &accepted
            ).trimmed();
            if (!accepted) {
                QMessageBox::information(nullptr,
                    QCoreApplication::translate("Launcher", "License Required"),
                    QCoreApplication::translate("Launcher", "A License provided by the administrator is required for the first launch."));
                return QString();
            }
            if (licenseKey.isEmpty()) {
                QMessageBox::warning(nullptr,
                    QCoreApplication::translate("Launcher", "License Cannot Be Empty"),
                    QCoreApplication::translate("Launcher", "Please paste the License created in the admin page."));
                promptReason.clear();
                continue;
            }
            if (!config.setValue("License", "license_key", licenseKey)) {
                QMessageBox::critical(nullptr,
                    QCoreApplication::translate("Launcher", "Failed to Save License"),
                    QCoreApplication::translate("Launcher", "Cannot write the configuration file:\n%1\n%2").arg(config.configPath(), config.lastError()));
                return QString();
            }
            progress.show();
            progress.setLabelText(QCoreApplication::translate("Launcher", "Verifying License..."));
            QApplication::processEvents();
            return licenseKey;
        }
    };

    while (true) {
        if (licenseKey.isEmpty()) {
            licenseKey = promptAndSaveLicense(QString());
            if (licenseKey.isEmpty()) return 0;
        }
        DeviceIdentityHelper identity(appDir);
        if (identity.ensureIssued(config.getValue("Server", "api_base_url"),
                                  config.getValue("Server", "client_token"),
                                  config.getValue("App", "app_id"),
                                  config.getValue("App", "channel"),
                                  licenseKey)) {
            break;
        }
        const QString error = identity.errorString();
        if (!isLicenseError(error)) {
            progress.close();
            QMessageBox::critical(nullptr,
                QCoreApplication::translate("Launcher", "Device Authentication Failed"),
                error);
            return -1;
        }
        clearDeviceCredential();
        licenseKey = promptAndSaveLicense(QCoreApplication::translate("Launcher", "The current License cannot be used: %1").arg(error));
        if (licenseKey.isEmpty()) return 0;
    }

    UpdateLogic logic;
    logic.checkUpdate();

    const bool needUpdate = logic.getNeedUpdate();
    const bool networkOk = logic.isNetworkOk();
    const QString latestVer = logic.getLatestVersion();
    const QJsonObject response = logic.getCheckResult();
    const int targetVersionId = response.value("version_id").toInt();
    const QString appId = logic.getAppId();
    const QString channel = logic.getChannel();
    const QString launchToken = config.getValue("App", "launch_token");
    const QString currentVersion = config.getValue("App", "current_version");

    if (logic.lastStatusCode() == 401 || logic.lastStatusCode() == 403) {
        progress.close();
        const QJsonValue detail = response.value("detail");
        const QString message = detail.isObject() ? detail.toObject().value("msg").toString() : detail.toString();
        const QString displayMessage = message.isEmpty()
            ? QCoreApplication::translate("Launcher", "The device or License authorization is invalid.")
            : message;
        if (isLicenseError(displayMessage)) {
            clearDeviceCredential();
            const QString newLicense = promptAndSaveLicense(QCoreApplication::translate("Launcher", "The current authorization was rejected by the server: %1").arg(displayMessage));
            if (!newLicense.isEmpty()) {
                progress.close();
                QMessageBox::information(nullptr,
                    QCoreApplication::translate("Launcher", "License Saved"),
                    QCoreApplication::translate("Launcher", "Please restart Launcher to complete device authorization and update checking."));
            }
            return 0;
        }
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Authorization Rejected"),
            displayMessage);
        return -1;
    }

    const auto configuredName = [&](const QString& key, const QString& fallback) {
        const QString value = config.getValue("Runtime", key).trimmed();
        return value.isEmpty() ? fallback : value;
    };
    const QString mainExecutable = configuredName("main_executable", "MainApp.exe");
    const QString updaterExecutable = configuredName("updater_executable", "Updater.exe");
    const QString mainAppPath = QDir(appDir).filePath(mainExecutable);
    const QString updaterPath = QDir(appDir).filePath(updaterExecutable);
    const auto importOfflinePackage = [&]() {
        const QString package = QFileDialog::getOpenFileName(nullptr,
            QCoreApplication::translate("Launcher", "Select Offline Update Package"),
            QString(),
            QCoreApplication::translate("Launcher", "Marsco offline update package (*.upd)"));
        return package.isEmpty() ? false : QProcess::startDetached(updaterPath, QStringList{QString("--offline-package=%1").arg(package)});
    };
    const QString deviceId = config.getValue("Update", "device_id");
    if (QCoreApplication::arguments().contains("--import-offline")) {
        progress.close();
        if (!importOfflinePackage())
            QMessageBox::information(nullptr,
                QCoreApplication::translate("Launcher", "Offline Update"),
                QCoreApplication::translate("Launcher", "No offline update package was selected."));
        return 0;
    }

    const auto startMainApp = [&]() {
        QString ticketPath;
        QString ticketError;
        if (!TicketHelper::createTicket(logic.getAppId(), deviceId, currentVersion,
                                        launchToken, &ticketPath, &ticketError)) {
            qDebug() << "Cannot create launch ticket:" << ticketError;
            return false;
        }
        const bool started = QProcess::startDetached(mainAppPath,
            QStringList{QString("--ticket-file=%1").arg(ticketPath)});
        if (!started) QFile::remove(ticketPath);
        return started;
    };

    progress.setLabelText(QCoreApplication::translate("Launcher", "Verifying local runtime policy..."));
    QApplication::processEvents();

    PolicyHelper policy(appDir);
    if (!policy.loadPolicy("config/version_policy.dat") || !policy.isValid())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Cannot Start"),
            QCoreApplication::translate("Launcher", "The local version policy is invalid: %1").arg(policy.errorString()));
        return -1;
    }
    if (policy.isExpired())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Cannot Start"),
            QCoreApplication::translate("Launcher", "The local version policy has expired. Please connect to the network or contact the administrator."));
        return -1;
    }
    if ((!policy.allowRun() || !policy.isVersionAllowed(currentVersion)) && !(networkOk && needUpdate))
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Current Version Cannot Run"),
            policy.message().isEmpty() ? QCoreApplication::translate("Launcher", "The current version %1 has been disabled by the administrator.").arg(currentVersion)
                                       : policy.message());
        return -1;
    }

    LocalStateHelper state(appDir);
    if (!state.loadState())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Cannot Start"),
            QCoreApplication::translate("Launcher", "Cannot read the local state: %1").arg(state.errorString()));
        return -1;
    }
    if (state.isPolicySeqRolledBack(policy.policySeq()))
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Security Check Failed"),
            QCoreApplication::translate("Launcher", "A version policy sequence rollback was detected. Startup has been blocked."));
        return -1;
    }
    if (state.isSystemTimeRewound())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Security Check Failed"),
            QCoreApplication::translate("Launcher", "A possible system time rollback was detected. Startup has been blocked."));
        return -1;
    }

    if (networkOk && needUpdate)
    {
        progress.close();
        const bool rollbackOperation = response.value("action").toString() == "rollback_allowed";
        const QString dialogTitle = rollbackOperation ? QCoreApplication::translate("Launcher", "Version Rollback")
            : (policy.forceUpdate() ? QCoreApplication::translate("Launcher", "Update Required") : QCoreApplication::translate("Launcher", "New Version Available"));
        const QString prompt = policy.message().isEmpty()
            ? (rollbackOperation
                ? QCoreApplication::translate("Launcher", "The administrator provided version %1 as the rollback target. Downgrade now?").arg(latestVer)
                : QCoreApplication::translate("Launcher", "Version %1 is available. Update now?").arg(latestVer))
            : policy.message() + QCoreApplication::translate("Launcher", "\nTarget version: %1").arg(latestVer);
        bool accepted = true;
        if (policy.forceUpdate()) {
            QMessageBox::information(nullptr, dialogTitle, prompt);
        } else {
            accepted = QMessageBox::question(nullptr, dialogTitle, prompt,
                QMessageBox::Yes | QMessageBox::No, QMessageBox::No) == QMessageBox::Yes;
        }
        if (!accepted) {
            if (!startMainApp()) {
                QMessageBox::critical(nullptr,
                    QCoreApplication::translate("Launcher", "Startup Failed"),
                    QCoreApplication::translate("Launcher", "Cannot start the main application: %1").arg(mainAppPath));
                return -1;
            }
            return 0;
        }
        const QStringList updaterArgs{appId, channel, latestVer, QString::number(targetVersionId)};
        if (!QProcess::startDetached(updaterPath, updaterArgs))
        {
            QMessageBox::critical(nullptr,
                QCoreApplication::translate("Launcher", "Updater Startup Failed"),
                QCoreApplication::translate("Launcher", "Cannot start the updater: %1").arg(updaterPath));
            return -1;
        }
        return 0;
    }

    if (networkOk && !needUpdate && targetVersionId > 0 && latestVer == currentVersion)
    {
        progress.setLabelText(QCoreApplication::translate("Launcher", "Caching signed version manifest..."));
        QApplication::processEvents();
        const QString manifestCacheDir = QDir(ConfigHelper::instance().updateRoot()).filePath("manifest_cache");
        if (!logic.cacheManifest(appId, channel, currentVersion, targetVersionId, manifestCacheDir))
        {
            progress.close();
            QMessageBox::critical(nullptr,
                QCoreApplication::translate("Launcher", "Manifest Cache Failed"),
                QCoreApplication::translate("Launcher", "Cannot cache the signed manifest for the current version: %1").arg(logic.errorString()));
            return -1;
        }
    }

    if (!networkOk) {
        progress.close();
        if (QMessageBox::question(nullptr,
                                  QCoreApplication::translate("Launcher", "Server Unavailable"),
                                  QCoreApplication::translate("Launcher", "Cannot connect to the update server. Import an offline update package?"),
                                  QMessageBox::Yes | QMessageBox::No, QMessageBox::No) == QMessageBox::Yes) {
            if (!importOfflinePackage())
                QMessageBox::information(nullptr,
                    QCoreApplication::translate("Launcher", "Offline Update"),
                    QCoreApplication::translate("Launcher", "No offline update package was selected, or the updater could not be started."));
            return 0;
        }
        progress.show();
    }

    if (!networkOk && !policy.isOfflineAllowed())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Network Unavailable"),
            QCoreApplication::translate("Launcher", "Cannot connect to the update server, and the current policy does not allow offline startup."));
        return -1;
    }

    progress.setLabelText(networkOk
        ? QCoreApplication::translate("Launcher", "The application is up to date. Starting...")
        : QCoreApplication::translate("Launcher", "Offline mode is active. Starting..."));
    QApplication::processEvents();
    if (!startMainApp())
    {
        progress.close();
        QMessageBox::critical(nullptr,
            QCoreApplication::translate("Launcher", "Startup Failed"),
            QCoreApplication::translate("Launcher", "Cannot start the main application: %1").arg(mainAppPath));
        return -1;
    }
    progress.close();
    return 0;
}