/*
    This file is part of KDE.

    SPDX-FileCopyrightText: 2009 Eckhart Wörner <ewoerner@kde.org>
    SPDX-FileCopyrightText: 2010 Frederik Gladhorn <gladhorn@kde.org>
    SPDX-FileCopyrightText: 2019 Dan Leinir Turthra Jensen <admin@leinir.dk>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL

*/

#include "kdeplatformdependent.h"

#include "attica_plugin_debug.h"

#include <KCMultiDialog>
#include <KConfigGroup>
#include <KLocalizedString>
#include <QNetworkDiskCache>
#include <QStorageInfo>

#include <Accounts/AccountService>
#include <Accounts/Manager>
#include <KAccounts/Core>
#include <KAccounts/GetCredentialsJob>

using namespace Attica;

KdePlatformDependent::KdePlatformDependent()
    : m_config(KSharedConfig::openConfig(QStringLiteral("atticarc")))
    , m_accessManager(nullptr)
{
    // FIXME: Investigate how to not leak this instance without crashing.
    m_accessManager = new QNetworkAccessManager(nullptr);

    const QString cacheDir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + QStringLiteral("/attica");
    QNetworkDiskCache *cache = new QNetworkDiskCache(m_accessManager);
    QStorageInfo storageInfo(QStandardPaths::writableLocation(QStandardPaths::CacheLocation));
    cache->setCacheDirectory(cacheDir);
    cache->setMaximumCacheSize(storageInfo.bytesTotal() / 1000);
    m_accessManager->setCache(cache);
}

KdePlatformDependent::~KdePlatformDependent()
{
}

// TODO Cache the account (so we can call getAccount a WHOLE LOT of times without making the application super slow)
// TODO Also don't just cache it forever, so reset to nullptr every so often, so we pick up potential new stuff the user's done
QString KdePlatformDependent::getAccessToken(const QUrl & /*baseUrl*/) const
{
    QString accessToken;
    QString idToken;
    Accounts::Manager *accountsManager = KAccounts::accountsManager();
    if (accountsManager) {
        static const QString serviceType{QStringLiteral("opendesktop-rating")};
        Accounts::AccountIdList accountIds = accountsManager->accountList(serviceType);
        // TODO Present the user with a choice in case there's more than one, but for now just pick the first successful one
        // loop through the accounts, and attempt to get them
        Accounts::Account *account{nullptr};
        for (const Accounts::AccountId &accountId : accountIds) {
            account = accountsManager->account(accountId);
            if (account) {
                bool completed{false};
                qCDebug(ATTICA_PLUGIN_LOG) << "Fetching data for" << accountId;
                GetCredentialsJob *job = new GetCredentialsJob(accountId, accountsManager);
                connect(job, &KJob::finished, [&completed, &accessToken, &idToken](KJob *kjob) {
                    GetCredentialsJob *job = qobject_cast<GetCredentialsJob *>(kjob);
                    const QVariantMap credentialsData = job->credentialsData();
                    accessToken = credentialsData[QStringLiteral("AccessToken")].toString();
                    idToken = credentialsData[QStringLiteral("IdToken")].toString();
                    // As this can be useful for more heavy duty debugging purposes, leaving this in so it doesn't have to be rewritten
                    //                     if (!accessToken.isEmpty()) {
                    //                         qCDebug(ATTICA_PLUGIN_LOG) << "Credentials data was retrieved";
                    //                         for (const QString& key : credentialsData.keys()) {
                    //                             qCDebug(ATTICA_PLUGIN_LOG) << key << credentialsData[key];
                    //                         }
                    //                     }
                    completed = true;
                });
                connect(job, &KJob::result, [&completed]() {
                    completed = true;
                });
                job->start();
                while (!completed) {
                    qApp->processEvents();
                }
                if (!idToken.isEmpty()) {
                    qCDebug(ATTICA_PLUGIN_LOG) << "OpenID Access token retrieved for account" << account->id();
                    break;
                }
            }
            if (idToken.isEmpty()) {
                // If we arrived here, we did have an opendesktop account, but without the id token, which means an old version of the signon oauth2 plugin was
                // used
                qCWarning(ATTICA_PLUGIN_LOG) << "We got an OpenDesktop account, but it seems to be lacking the id token. This means an old SignOn OAuth2 "
                                                "plugin was used for logging in. The plugin may have been upgraded in the meantime, but an account created "
                                                "using the old plugin cannot be used, and you must log out and back in again.";
            }
        }
    } else {
        qCDebug(ATTICA_PLUGIN_LOG) << "No accounts manager could be fetched, so could not ask it for account details";
    }

    return idToken;
}

QUrl baseUrlFromRequest(const QNetworkRequest &request)
{
    const QUrl url{request.url()};
    QString baseUrl = QLatin1String("%1://%2").arg(url.scheme(), url.host());
    int port = url.port();
    if (port != -1) {
        baseUrl.append(QString::number(port));
    }
    return url;
}

QNetworkRequest KdePlatformDependent::addOAuthToRequest(const QNetworkRequest &request)
{
    QNetworkRequest notConstReq = const_cast<QNetworkRequest &>(request);
    const QString token{getAccessToken(baseUrlFromRequest(request))};
    if (!token.isEmpty()) {
        const QString bearer_format = QStringLiteral("Bearer %1");
        const QString bearer = bearer_format.arg(token);
        notConstReq.setRawHeader("Authorization", bearer.toUtf8());
    }
    notConstReq.setAttribute(QNetworkRequest::Http2AllowedAttribute, true);

    // Add cache preference in a granular fashion (we will almost certainly want more of these, but...)
    static const QStringList preferCacheEndpoints{QLatin1String{"/content/categories"}};
    for (const QString &endpoint : preferCacheEndpoints) {
        if (notConstReq.url().toString().endsWith(endpoint)) {
            QNetworkCacheMetaData cacheMeta{m_accessManager->cache()->metaData(notConstReq.url())};
            if (cacheMeta.isValid()) {
                // If the expiration date is valid, but longer than 24 hours, don't trust that things
                // haven't changed and check first, otherwise just use the cached version to relieve
                // server strain and reduce network traffic.
                const QDateTime tomorrow{QDateTime::currentDateTime().addDays(1)};
                if (cacheMeta.expirationDate().isValid() && cacheMeta.expirationDate() < tomorrow) {
                    notConstReq.setAttribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferCache);
                }
            }
            break;
        }
    }

    return notConstReq;
}

QNetworkReply *KdePlatformDependent::post(const QNetworkRequest &request, const QByteArray &data)
{
    return m_accessManager->post(addOAuthToRequest(removeAuthFromRequest(request)), data);
}

QNetworkReply *KdePlatformDependent::post(const QNetworkRequest &request, QIODevice *data)
{
    return m_accessManager->post(addOAuthToRequest(removeAuthFromRequest(request)), data);
}

QNetworkReply *KdePlatformDependent::get(const QNetworkRequest &request)
{
    return m_accessManager->get(addOAuthToRequest(removeAuthFromRequest(request)));
}

QNetworkRequest KdePlatformDependent::removeAuthFromRequest(const QNetworkRequest &request)
{
    const QStringList noauth = {QStringLiteral("no-auth-prompt"), QStringLiteral("true")};
    QNetworkRequest notConstReq = const_cast<QNetworkRequest &>(request);
    notConstReq.setAttribute(QNetworkRequest::User, noauth);
    return notConstReq;
}

bool KdePlatformDependent::saveCredentials(const QUrl & /*baseUrl*/, const QString & /*user*/, const QString & /*password*/)
{
    qCDebug(ATTICA_PLUGIN_LOG) << "Launch the KAccounts control module";
    // TODO KF6 This will want replacing with a call named something that suggests calling it shows accounts (and perhaps
    // directly requests the accounts kcm to start adding a new account if it's not there, maybe even pre-fills the fields...)

    KCMultiDialog *dialog = new KCMultiDialog;
    dialog->addModule(KPluginMetaData(QStringLiteral("kcm_kaccounts")));
    dialog->setAttribute(Qt::WA_DeleteOnClose);
    dialog->show();

    return true;
}

bool KdePlatformDependent::hasCredentials(const QUrl &baseUrl) const
{
    qCDebug(ATTICA_PLUGIN_LOG) << Q_FUNC_INFO;
    return !getAccessToken(baseUrl).isEmpty();
}

bool KdePlatformDependent::loadCredentials(const QUrl &baseUrl, QString &user, QString & /*password*/)
{
    qCDebug(ATTICA_PLUGIN_LOG) << Q_FUNC_INFO;
    QString token = getAccessToken(baseUrl);
    if (!token.isEmpty()) {
        user = token;
    }
    return !token.isEmpty();
}

bool Attica::KdePlatformDependent::askForCredentials(const QUrl &baseUrl, QString &user, QString &password)
{
    Q_UNUSED(baseUrl);
    Q_UNUSED(user);
    Q_UNUSED(password);

    return false;
}

QList<QUrl> KdePlatformDependent::getDefaultProviderFiles() const
{
    KConfigGroup group(m_config, "General");
    const QStringList pathStrings = group.readPathEntry("providerFiles", QStringList(QStringLiteral("https://autoconfig.kde.org/ocs/providers.xml")));
    QList<QUrl> paths;
    for (const QString &pathString : pathStrings) {
        paths.append(QUrl(pathString));
    }
    qCDebug(ATTICA_PLUGIN_LOG) << "Loaded paths from config:" << paths;
    return paths;
}

void KdePlatformDependent::addDefaultProviderFile(const QUrl &url)
{
    KConfigGroup group(m_config, "General");
    QStringList pathStrings = group.readPathEntry("providerFiles", QStringList(QStringLiteral("https://autoconfig.kde.org/ocs/providers.xml")));
    QString urlString = url.toString();
    if (!pathStrings.contains(urlString)) {
        pathStrings.append(urlString);
        group.writeEntry("providerFiles", pathStrings);
        group.sync();
        qCDebug(ATTICA_PLUGIN_LOG) << "wrote providers: " << pathStrings;
    }
}

void KdePlatformDependent::removeDefaultProviderFile(const QUrl &url)
{
    KConfigGroup group(m_config, "General");
    QStringList pathStrings = group.readPathEntry("providerFiles", QStringList(QStringLiteral("https://autoconfig.kde.org/ocs/providers.xml")));
    pathStrings.removeAll(url.toString());
    group.writeEntry("providerFiles", pathStrings);
}

void KdePlatformDependent::enableProvider(const QUrl &baseUrl, bool enabled) const
{
    KConfigGroup group(m_config, "General");
    QStringList pathStrings = group.readPathEntry("disabledProviders", QStringList());
    if (enabled) {
        pathStrings.removeAll(baseUrl.toString());
    } else {
        if (!pathStrings.contains(baseUrl.toString())) {
            pathStrings.append(baseUrl.toString());
        }
    }
    group.writeEntry("disabledProviders", pathStrings);
    group.sync();
}

bool KdePlatformDependent::isEnabled(const QUrl &baseUrl) const
{
    KConfigGroup group(m_config, "General");
    return !group.readPathEntry("disabledProviders", QStringList()).contains(baseUrl.toString());
}

QNetworkAccessManager *Attica::KdePlatformDependent::nam()
{
    return m_accessManager;
}
