// 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 "systemdsignaldispatcher.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();
    }

    new ApplicationManager1Adaptor{this};

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

    m_jobManager.reset(new JobManager1Service(this));

    auto &dispatcher = SystemdSignalDispatcher::instance();

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

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

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

                const auto &appRef = *appIt;
                const auto &applicationPath = appRef->m_applicationPath.path();

                if (!appRef->addOneInstance(instanceId, applicationPath, systemdUnitPath.path())) [[likely]] {
                    qCritical() << "add Instance failed:" << applicationPath << unitName << systemdUnitPath.path();
                }

                return;
            });

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

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

                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) {
                                                   return value->systemdUnitPath() == systemdUnitPath;
                                               });

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

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

void ApplicationManager1Service::removeOneApplication(const QDBusObjectPath &application)
{
    if (auto it = m_applicationList.find(application); it != m_applicationList.cend()) {
        unregisterObjectFromDBus(application.path());
        m_applicationList.remove(application);
    }
}

void ApplicationManager1Service::removeAllApplication()
{
    for (const auto &app : m_applicationList.keys()) {
        removeOneApplication(app);
    }
}

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;
}

void ApplicationManager1Service::updateApplication(const QSharedPointer<ApplicationService> &destApp,
                                                   const DesktopFile &desktopFile) noexcept
{
    struct stat buf;
    const auto *filePath = desktopFile.filePath().toLocal8Bit().data();
    if (auto ret = stat(filePath, &buf); ret == -1) {
        qWarning() << "get file" << filePath << "state failed:" << std::strerror(errno);
        return;
    }

    constexpr std::size_t secToNano = 1e9;

    if (destApp->m_desktopSource.m_file.modified(buf.st_mtim.tv_sec * secToNano + buf.st_mtim.tv_nsec)) {
        auto newEntry = new DesktopEntry{};
        auto err = newEntry->parse(destApp->m_desktopSource.m_file);
        if (err != DesktopErrorCode::NoError and err != DesktopErrorCode::EntryKeyInvalid) {
            qWarning() << "update desktop file failed:" << err << ", content wouldn't change.";
            return;
        }
        destApp->m_entry.reset(newEntry);
    }
}

void ApplicationManager1Service::UpdateApplicationInfo(const QStringList &appIdList)
{
    for (const auto &appId : appIdList) {
        DesktopErrorCode err{DesktopErrorCode::NotFound};
        auto file = DesktopFile::searchDesktopFileById(appId, err);
        auto destApp = std::find_if(m_applicationList.cbegin(),
                                    m_applicationList.cend(),
                                    [&appId](const QSharedPointer<ApplicationService> &app) { return appId == app->id(); });

        if (err == DesktopErrorCode::NotFound) {
            removeOneApplication(destApp.key());
            continue;
        }

        if (destApp != m_applicationList.cend()) {
            updateApplication(destApp.value(), file.value());
            continue;
        }

        addApplication(std::move(file).value());
    }
}