// SPDX-FileCopyrightText: 2023 UnionTech Software Technology Co., Ltd.
//
// SPDX-License-Identifier: LGPL-3.0-or-later
#include "dbus/applicationmanager1service.h"
#include "dbus/applicationmanager1adaptor.h"
#include <QFile>
#include <unistd.h>

ApplicationManager1Service::~ApplicationManager1Service() = default;

ApplicationManager1Service::ApplicationManager1Service(std::unique_ptr<Identifier> ptr, QDBusConnection &connection)
    : m_identifier(std::move(ptr))
{
    if (!connection.registerService(DDEApplicationManager1ServiceName)) {
        qFatal() << connection.lastError();
    }

    if (!registerObjectToDBus(new ApplicationManager1Adaptor{this},
                              DDEApplicationManager1ObjectPath,
                              getDBusInterface<ApplicationManager1Adaptor>())) {
        std::terminate();
    }

    m_jobManager.reset(new JobManager1Service(this));

    auto &dispatcher = SystemdSignalDispatcher::instance();

    connect(&dispatcher,
            &SystemdSignalDispatcher::SystemdUnitNew,
            this,
            [this](QString serviceName, QDBusObjectPath systemdUnitPath) {
                auto [appId, instanceId] = processServiceName(serviceName);
                if (appId.isEmpty()) {
                    return;
                }

                for (const auto &app : m_applicationList) {
                    if (app->id() == appId) [[unlikely]] {
                        const auto &applicationPath = app->m_applicationPath.path();
                        if (!app->addOneInstance(instanceId, applicationPath, systemdUnitPath.path())) {
                            qWarning() << "add Instance failed:" << applicationPath << serviceName << systemdUnitPath.path();
                        }
                        return;
                    }
                }

                qWarning() << "couldn't find application:" << serviceName << "in application manager.";
            });

    connect(&dispatcher,
            &SystemdSignalDispatcher::SystemdUnitRemoved,
            this,
            [this](QString serviceName, QDBusObjectPath systemdUnitPath) {
                auto pair = processServiceName(serviceName);
                auto appId = pair.first, instanceId = pair.second;
                if (appId.isEmpty()) {
                    return;
                }

                auto appIt = std::find_if(m_applicationList.cbegin(),
                                          m_applicationList.cend(),
                                          [&appId](const QSharedPointer<ApplicationService> &app) {
                                              if (app->id() == appId) {
                                                  return true;
                                              }
                                              return false;
                                          });

                if (appIt == m_applicationList.cend()) [[unlikely]] {
                    qWarning() << "couldn't find app" << appId << "in application manager.";
                    return;
                }

                const auto &appRef = *appIt;

                auto instanceIt = std::find_if(appRef->m_Instances.cbegin(),
                                               appRef->m_Instances.cend(),
                                               [&systemdUnitPath](const QSharedPointer<InstanceService> &value) {
                                                   if (value->systemdUnitPath() == systemdUnitPath) {
                                                       return true;
                                                   }
                                                   return false;
                                               });

                if (instanceIt != appRef->m_Instances.cend()) [[likely]] {
                    appRef->removeOneInstance(instanceIt.key());
                }
            });
}

QPair<QString, QString> ApplicationManager1Service::processServiceName(const QString &serviceName)
{
    QString instanceId;
    QString applicationId;

    if (serviceName.endsWith(".service")) {
        auto lastDotIndex = serviceName.lastIndexOf('.');
        auto app = serviceName.sliced(0, lastDotIndex - 1);  // remove suffix

        if (app.contains('@')) {
            auto atIndex = app.indexOf('@');
            instanceId = app.sliced(atIndex + 1);
            app.remove(atIndex, instanceId.length() + 1);
        }

        applicationId = app.split('-').last();  // drop launcher if it exists.
    } else if (serviceName.endsWith(".scope")) {
        auto lastDotIndex = serviceName.lastIndexOf('.');
        auto app = serviceName.sliced(0, lastDotIndex - 1);

        auto components = app.split('-');
        instanceId = components.takeLast();
        applicationId = components.takeLast();
    } else {
        qDebug() << "it's not service or slice or scope.";
        return {};
    }

    if (instanceId.isEmpty()) {
        instanceId = QUuid::createUuid().toString(QUuid::Id128);
    }

    return qMakePair(std::move(applicationId), std::move(instanceId));
}

QList<QDBusObjectPath> ApplicationManager1Service::list() const
{
    return m_applicationList.keys();
}

bool ApplicationManager1Service::removeOneApplication(const QDBusObjectPath &application)
{
    return m_applicationList.remove(application) != 0;
}

void ApplicationManager1Service::removeAllApplication()
{
    m_applicationList.clear();
}

QDBusObjectPath ApplicationManager1Service::Application(const QString &id) const
{
    auto ret = std::find_if(m_applicationList.cbegin(), m_applicationList.cend(), [&id](const auto &app) {
        if (app->id() == id) {
            return true;
        }
        return false;
    });

    if (ret != m_applicationList.cend()) {
        return ret.key();
    }
    return {};
}

QString ApplicationManager1Service::Identify(const QDBusUnixFileDescriptor &pidfd,
                                             QDBusObjectPath &application,
                                             QDBusObjectPath &application_instance)
{
    if (!pidfd.isValid()) {
        qWarning() << "pidfd isn't a valid unix file descriptor";
        return {};
    }

    Q_ASSERT_X(static_cast<bool>(m_identifier), "Identify", "Broken Identifier.");

    QString fdFilePath = QString{"/proc/self/fdinfo/%1"}.arg(pidfd.fileDescriptor());
    QFile fdFile{fdFilePath};
    if (!fdFile.open(QFile::ExistingOnly | QFile::ReadOnly | QFile::Text)) {
        qWarning() << "open " << fdFilePath << "failed: " << fdFile.errorString();
        return {};
    }
    auto content = fdFile.readAll();
    QTextStream stream{content};
    QString appPid;
    while (!stream.atEnd()) {
        auto line = stream.readLine();
        if (line.startsWith("Pid")) {
            appPid = line.split(":").last().trimmed();
            break;
        }
    }
    if (appPid.isEmpty()) {
        qWarning() << "can't find pid which corresponding with the instance of this application.";
        return {};
    }
    bool ok;
    auto pid = appPid.toUInt(&ok);
    if (!ok) {
        qWarning() << "AppId is failed to convert to uint.";
        return {};
    }

    const auto ret = m_identifier->Identify(pid);

    auto app = std::find_if(m_applicationList.cbegin(), m_applicationList.cend(), [&ret](const auto &appPtr) {
        return appPtr->id() == ret.ApplicationId;
    });
    if (app == m_applicationList.cend()) {
        qWarning() << "can't find application:" << ret.ApplicationId;
        return {};
    }
    application = m_applicationList.key(*app);
    application_instance = (*app)->findInstance(ret.InstanceId);
    return ret.ApplicationId;
}

QDBusObjectPath ApplicationManager1Service::Launch(const QString &id,
                                                   const QString &actions,
                                                   const QStringList &fields,
                                                   const QVariantMap &options)
{
    auto app = Application(id);
    if (app.path().isEmpty()) {
        qWarning() << "No such application.";
        return {};
    }
    const auto &value = m_applicationList.value(app);
    return value->Launch(actions, fields, options);
}

void ApplicationManager1Service::UpdateApplicationInfo(const QStringList &update_path) {}