/* -*- mode: c++; c-basic-offset:4 -*-
    models/keycache.cpp

    This file is part of Kleopatra, the KDE keymanager
    SPDX-FileCopyrightText: 2007, 2008 Klarälvdalens Datakonsult AB
    SPDX-FileCopyrightText: 2018 Intevation GmbH
    SPDX-FileCopyrightText: 2020, 2021 g10 Code GmbH
    SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include <config-libkleo.h>

#include "keycache.h"
#include "keycache_p.h"

#include <libkleo/algorithm.h>
#include <libkleo/compat.h>
#include <libkleo/debug.h>
#include <libkleo/dn.h>
#include <libkleo/enum.h>
#include <libkleo/filesystemwatcher.h>
#include <libkleo/gnupg.h>
#include <libkleo/keygroup.h>
#include <libkleo/keygroupconfig.h>
#include <libkleo/keyhelpers.h>
#include <libkleo/predicates.h>
#include <libkleo/qtstlhelpers.h>
#include <libkleo/stl_util.h>

#include <libkleo_debug.h>

#include <KSharedConfig>

#include <QGpgME/CryptoConfig>
#include <QGpgME/ListAllKeysJob>
#include <QGpgME/Protocol>

#include <QEventLoop>
#include <QPointer>
#include <QTimer>

#include <gpgme++/context.h>
#include <gpgme++/decryptionresult.h>
#include <gpgme++/error.h>
#include <gpgme++/key.h>
#include <gpgme++/keylistresult.h>
#include <gpgme++/verificationresult.h>

#include <gpg-error.h>

#include <algorithm>
#include <chrono>
#include <functional>
#include <iterator>
#include <utility>

using namespace std::chrono_literals;
using namespace Kleo;
using namespace GpgME;

static const unsigned int hours2ms = 1000 * 60 * 60;

//
//
// KeyCache
//
//

namespace
{

make_comparator_str(ByEMail, .first.c_str());

}

class Kleo::KeyCacheAutoRefreshSuspension
{
    KeyCacheAutoRefreshSuspension()
    {
        qCDebug(LIBKLEO_LOG) << __func__;
        auto cache = KeyCache::mutableInstance();
        cache->enableFileSystemWatcher(false);
        m_refreshInterval = cache->refreshInterval();
        cache->setRefreshInterval(0);
        cache->cancelKeyListing();
        m_cache = cache;
    }

public:
    ~KeyCacheAutoRefreshSuspension()
    {
        qCDebug(LIBKLEO_LOG) << __func__;
        if (auto cache = m_cache.lock()) {
            cache->enableFileSystemWatcher(true);
            cache->setRefreshInterval(m_refreshInterval);
        }
    }

    static std::shared_ptr<KeyCacheAutoRefreshSuspension> instance()
    {
        static std::weak_ptr<KeyCacheAutoRefreshSuspension> self;
        if (auto s = self.lock()) {
            return s;
        } else {
            s = std::shared_ptr<KeyCacheAutoRefreshSuspension>{new KeyCacheAutoRefreshSuspension{}};
            self = s;
            return s;
        }
    }

private:
    std::weak_ptr<KeyCache> m_cache;
    int m_refreshInterval = 0;
};

class KeyCache::Private
{
    friend class ::Kleo::KeyCache;
    KeyCache *const q;

public:
    explicit Private(KeyCache *qq)
        : q(qq)
        , m_refreshInterval(1)
        , m_initalized(false)
        , m_pgpOnly(true)
        , m_remarks_enabled(false)
    {
        connect(&m_autoKeyListingTimer, &QTimer::timeout, q, [this]() {
            q->startKeyListing();
        });
        updateAutoKeyListingTimer();
    }

    ~Private()
    {
        if (m_refreshJob) {
            m_refreshJob->cancel();
        }
    }

    template<template<template<typename U> class Op> class Comp>
    std::vector<Key>::const_iterator find(const std::vector<Key> &keys, const char *key) const
    {
        ensureCachePopulated();
        const auto it = std::lower_bound(keys.begin(), keys.end(), key, Comp<std::less>());
        if (it == keys.end() || Comp<std::equal_to>()(*it, key)) {
            return it;
        } else {
            return keys.end();
        }
    }

    template<template<template<typename U> class Op> class Comp>
    std::vector<Subkey>::const_iterator find(const std::vector<Subkey> &keys, const char *key) const
    {
        ensureCachePopulated();
        const auto it = std::lower_bound(keys.begin(), keys.end(), key, Comp<std::less>());
        if (it == keys.end() || Comp<std::equal_to>()(*it, key)) {
            return it;
        } else {
            return keys.end();
        }
    }

    std::vector<Key>::const_iterator find_fpr(const char *fpr) const
    {
        return find<_detail::ByFingerprint>(by.fpr, fpr);
    }

    std::pair<std::vector<std::pair<std::string, Key>>::const_iterator, std::vector<std::pair<std::string, Key>>::const_iterator>
    find_email(const char *email) const
    {
        ensureCachePopulated();
        return std::equal_range(by.email.begin(), by.email.end(), email, ByEMail<std::less>());
    }

    std::vector<Key> find_mailbox(const QString &email, bool sign) const;

    std::vector<Subkey>::const_iterator find_subkeyfpr(const char *subkeyfpr) const
    {
        return find<_detail::BySubkeyFingerprint>(by.subkeyfpr, subkeyfpr);
    }

    std::vector<Subkey>::const_iterator find_keygrip(const char *keygrip) const
    {
        return find<_detail::ByKeyGrip>(by.keygrip, keygrip);
    }

    std::vector<Subkey>::const_iterator find_subkeyid(const char *subkeyid) const
    {
        return find<_detail::ByKeyID>(by.subkeyid, subkeyid);
    }

    std::vector<Key>::const_iterator find_keyid(const char *keyid) const
    {
        return find<_detail::ByKeyID>(by.keyid, keyid);
    }

    std::pair<std::vector<Key>::const_iterator, std::vector<Key>::const_iterator> find_subjects(const char *chain_id) const
    {
        ensureCachePopulated();
        return std::equal_range(by.chainid.begin(), by.chainid.end(), chain_id, _detail::ByChainID<std::less>());
    }

    void refreshJobDone(const KeyListResult &result);

    void setRefreshInterval(int interval)
    {
        m_refreshInterval = interval;
        updateAutoKeyListingTimer();
    }

    int refreshInterval() const
    {
        return m_refreshInterval;
    }

    void updateAutoKeyListingTimer()
    {
        setAutoKeyListingInterval(hours2ms * m_refreshInterval);
    }
    void setAutoKeyListingInterval(int ms)
    {
        m_autoKeyListingTimer.stop();
        m_autoKeyListingTimer.setInterval(ms);
        if (ms != 0) {
            m_autoKeyListingTimer.start();
        }
    }

    void ensureCachePopulated() const;

    void readGroupsFromGpgConf()
    {
        // According to Werner Koch groups are more of a hack to solve
        // a valid usecase (e.g. several keys defined for an internal mailing list)
        // that won't make it in the proper keylist interface. And using gpgconf
        // was the suggested way to support groups.
        auto conf = QGpgME::cryptoConfig();
        if (!conf) {
            return;
        }

        auto entry = getCryptoConfigEntry(conf, "gpg", "group");
        if (!entry) {
            return;
        }

        // collect the key fingerprints for all groups read from the configuration
        QMap<QString, QStringList> fingerprints;
        const auto stringValueList = entry->stringValueList();
        for (const QString &value : stringValueList) {
            const QStringList split = value.split(QLatin1Char('='));
            if (split.size() != 2) {
                qCDebug(LIBKLEO_LOG) << "Ignoring invalid group config:" << value;
                continue;
            }
            const QString groupName = split[0];
            const QString fingerprint = split[1];
            fingerprints[groupName].push_back(fingerprint);
        }

        // add all groups read from the configuration to the list of groups
        for (auto it = fingerprints.cbegin(); it != fingerprints.cend(); ++it) {
            const QString groupName = it.key();
            const std::vector<Key> groupKeys = q->findByFingerprint(toStdStrings(it.value()));
            KeyGroup g(groupName, groupName, groupKeys, KeyGroup::GnuPGConfig);
            m_groups.push_back(g);
        }
    }

    void readGroupsFromGroupsConfig()
    {
        Q_ASSERT(m_groupConfig);
        if (!m_groupConfig) {
            qCWarning(LIBKLEO_LOG) << __func__ << "group config not set";
            return;
        }

        m_groups = m_groupConfig->readGroups();
    }

    KeyGroup writeGroupToGroupsConfig(const KeyGroup &group)
    {
        Q_ASSERT(m_groupConfig);
        if (!m_groupConfig) {
            qCWarning(LIBKLEO_LOG) << __func__ << "group config not set";
            return {};
        }

        Q_ASSERT(!group.isNull());
        Q_ASSERT(group.source() == KeyGroup::ApplicationConfig);
        if (group.isNull() || group.source() != KeyGroup::ApplicationConfig) {
            qCDebug(LIBKLEO_LOG) << __func__ << "group cannot be written to application configuration:" << group;
            return group;
        }

        return m_groupConfig->writeGroup(group);
    }

    bool removeGroupFromGroupsConfig(const KeyGroup &group)
    {
        Q_ASSERT(m_groupConfig);
        if (!m_groupConfig) {
            qCWarning(LIBKLEO_LOG) << __func__ << "group config not set";
            return false;
        }

        Q_ASSERT(!group.isNull());
        Q_ASSERT(group.source() == KeyGroup::ApplicationConfig);
        if (group.isNull() || group.source() != KeyGroup::ApplicationConfig) {
            qCDebug(LIBKLEO_LOG) << __func__ << "group cannot be removed from application configuration:" << group;
            return false;
        }

        return m_groupConfig->removeGroup(group);
    }

    void updateGroupCache()
    {
        // Update Group Keys
        // this is a quick thing as it only involves reading the config
        // so no need for a job.

        m_groups.clear();
        if (m_groupsEnabled) {
            readGroupsFromGpgConf();
            readGroupsFromGroupsConfig();
        }
    }

    bool insert(const KeyGroup &group)
    {
        Q_ASSERT(!group.isNull());
        Q_ASSERT(group.source() == KeyGroup::ApplicationConfig);
        if (group.isNull() || group.source() != KeyGroup::ApplicationConfig) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::insert - Invalid group:" << group;
            return false;
        }
        const auto it = std::find_if(m_groups.cbegin(), m_groups.cend(), [group](const auto &g) {
            return g.source() == group.source() && g.id() == group.id();
        });
        if (it != m_groups.cend()) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::insert - Group already present in list of groups:" << group;
            return false;
        }

        const KeyGroup savedGroup = writeGroupToGroupsConfig(group);
        if (savedGroup.isNull()) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::insert - Writing group" << group.id() << "to config file failed";
            return false;
        }

        m_groups.push_back(savedGroup);

        Q_EMIT q->groupAdded(savedGroup);

        return true;
    }

    bool update(const KeyGroup &group)
    {
        Q_ASSERT(!group.isNull());
        Q_ASSERT(group.source() == KeyGroup::ApplicationConfig);
        if (group.isNull() || group.source() != KeyGroup::ApplicationConfig) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::update - Invalid group:" << group;
            return false;
        }
        const auto it = std::find_if(m_groups.cbegin(), m_groups.cend(), [group](const auto &g) {
            return g.source() == group.source() && g.id() == group.id();
        });
        if (it == m_groups.cend()) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::update - Group not found in list of groups:" << group;
            return false;
        }
        const auto groupIndex = std::distance(m_groups.cbegin(), it);

        const KeyGroup savedGroup = writeGroupToGroupsConfig(group);
        if (savedGroup.isNull()) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::update - Writing group" << group.id() << "to config file failed";
            return false;
        }

        m_groups[groupIndex] = savedGroup;

        Q_EMIT q->groupUpdated(savedGroup);

        return true;
    }

    bool remove(const KeyGroup &group)
    {
        Q_ASSERT(!group.isNull());
        Q_ASSERT(group.source() == KeyGroup::ApplicationConfig);
        if (group.isNull() || group.source() != KeyGroup::ApplicationConfig) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::remove - Invalid group:" << group;
            return false;
        }
        const auto it = std::find_if(m_groups.cbegin(), m_groups.cend(), [group](const auto &g) {
            return g.source() == group.source() && g.id() == group.id();
        });
        if (it == m_groups.cend()) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::remove - Group not found in list of groups:" << group;
            return false;
        }

        const bool success = removeGroupFromGroupsConfig(group);
        if (!success) {
            qCDebug(LIBKLEO_LOG) << "KeyCache::Private::remove - Removing group" << group.id() << "from config file failed";
            return false;
        }

        m_groups.erase(it);

        Q_EMIT q->groupRemoved(group);

        return true;
    }

private:
    QPointer<RefreshKeysJob> m_refreshJob;
    std::vector<std::shared_ptr<FileSystemWatcher>> m_fsWatchers;
    QTimer m_autoKeyListingTimer;
    int m_refreshInterval;

    struct By {
        std::vector<Key> fpr, keyid, chainid;
        std::vector<std::pair<std::string, Key>> email;
        std::vector<Subkey> subkeyfpr, subkeyid, keygrip;
    } by;
    bool m_initalized;
    bool m_pgpOnly;
    bool m_remarks_enabled;
    bool m_groupsEnabled = false;
    std::shared_ptr<KeyGroupConfig> m_groupConfig;
    std::vector<KeyGroup> m_groups;
    std::unordered_map<QByteArray, std::vector<CardKeyStorageInfo>> m_cards;
};

std::shared_ptr<const KeyCache> KeyCache::instance()
{
    return mutableInstance();
}

std::shared_ptr<KeyCache> KeyCache::mutableInstance()
{
    static std::weak_ptr<KeyCache> self;
    try {
        return std::shared_ptr<KeyCache>(self);
    } catch (const std::bad_weak_ptr &) {
        const std::shared_ptr<KeyCache> s(new KeyCache);
        self = s;
        return s;
    }
}

KeyCache::KeyCache()
    : QObject()
    , d(new Private(this))
{
}

KeyCache::~KeyCache()
{
}

void KeyCache::setGroupsEnabled(bool enabled)
{
    d->m_groupsEnabled = enabled;
    if (d->m_initalized) {
        d->updateGroupCache();
    }
}

void KeyCache::setGroupConfig(const std::shared_ptr<KeyGroupConfig> &groupConfig)
{
    d->m_groupConfig = groupConfig;
}

void KeyCache::enableFileSystemWatcher(bool enable)
{
    for (const auto &i : std::as_const(d->m_fsWatchers)) {
        i->setEnabled(enable);
    }
}

void KeyCache::setRefreshInterval(int hours)
{
    d->setRefreshInterval(hours);
}

int KeyCache::refreshInterval() const
{
    return d->refreshInterval();
}

std::shared_ptr<KeyCacheAutoRefreshSuspension> KeyCache::suspendAutoRefresh()
{
    return KeyCacheAutoRefreshSuspension::instance();
}

void KeyCache::reload(GpgME::Protocol /*proto*/, ReloadOption option)
{
    qCDebug(LIBKLEO_LOG) << this << __func__ << "option:" << option;
    const bool forceReload = option & ForceReload;
    if (d->m_refreshJob && !forceReload) {
        qCDebug(LIBKLEO_LOG) << this << __func__ << "- refresh already running";
        return;
    }
    if (d->m_refreshJob) {
        disconnect(d->m_refreshJob.data(), nullptr, this, nullptr);
        d->m_refreshJob->cancel();
        d->m_refreshJob.clear();
    }

    d->updateAutoKeyListingTimer();

    enableFileSystemWatcher(false);
    d->m_refreshJob = new RefreshKeysJob(this);
    connect(d->m_refreshJob.data(), &RefreshKeysJob::done, this, [this](const GpgME::KeyListResult &r) {
        qCDebug(LIBKLEO_LOG) << d->m_refreshJob.data() << "RefreshKeysJob::done";
        d->refreshJobDone(r);
    });
    connect(d->m_refreshJob.data(), &RefreshKeysJob::canceled, this, [this]() {
        qCDebug(LIBKLEO_LOG) << d->m_refreshJob.data() << "RefreshKeysJob::canceled";
        d->m_refreshJob.clear();
    });
    d->m_refreshJob->start();
}

void KeyCache::cancelKeyListing()
{
    if (!d->m_refreshJob) {
        return;
    }
    d->m_refreshJob->cancel();
}

void KeyCache::addFileSystemWatcher(const std::shared_ptr<FileSystemWatcher> &watcher)
{
    if (!watcher) {
        return;
    }
    d->m_fsWatchers.push_back(watcher);
    connect(watcher.get(), &FileSystemWatcher::directoryChanged, this, [this]() {
        startKeyListing();
    });
    connect(watcher.get(), &FileSystemWatcher::fileChanged, this, [this]() {
        startKeyListing();
    });

    watcher->setEnabled(d->m_refreshJob.isNull());
}

void KeyCache::enableRemarks(bool value)
{
    if (!d->m_remarks_enabled && value) {
        d->m_remarks_enabled = value;
        if (d->m_initalized && !d->m_refreshJob) {
            qCDebug(LIBKLEO_LOG) << "Reloading keycache with remarks enabled";
            reload();
        }
    } else {
        d->m_remarks_enabled = value;
    }
}

bool KeyCache::remarksEnabled() const
{
    return d->m_remarks_enabled;
}

void KeyCache::Private::refreshJobDone(const KeyListResult &result)
{
    m_refreshJob.clear();
    q->enableFileSystemWatcher(true);
    if (!m_initalized && q->remarksEnabled()) {
        // trigger another key listing to read signatures and signature notations
        QMetaObject::invokeMethod(
            q,
            [this]() {
                qCDebug(LIBKLEO_LOG) << "Reloading keycache with remarks enabled";
                q->reload();
            },
            Qt::QueuedConnection);
    }
    m_initalized = true;
    updateGroupCache();
    Q_EMIT q->keyListingDone(result);
}

const Key &KeyCache::findByFingerprint(const char *fpr) const
{
    const std::vector<Key>::const_iterator it = d->find_fpr(fpr);
    if (it == d->by.fpr.end()) {
        static const Key null;
        return null;
    } else {
        return *it;
    }
}

const Key &KeyCache::findByFingerprint(const std::string &fpr) const
{
    return findByFingerprint(fpr.c_str());
}

std::vector<GpgME::Key> KeyCache::findByFingerprint(const std::vector<std::string> &fprs) const
{
    std::vector<Key> keys;
    keys.reserve(fprs.size());
    for (const auto &fpr : fprs) {
        const Key key = findByFingerprint(fpr.c_str());
        if (key.isNull()) {
            qCDebug(LIBKLEO_LOG) << __func__ << "Ignoring unknown key with fingerprint:" << fpr.c_str();
            continue;
        }
        keys.push_back(key);
    }
    return keys;
}

std::vector<Key> KeyCache::findByEMailAddress(const char *email) const
{
    const auto pair = d->find_email(email);
    std::vector<Key> result;
    result.reserve(std::distance(pair.first, pair.second));
    std::transform(pair.first, pair.second, std::back_inserter(result), [](const std::pair<std::string, Key> &pair) {
        return pair.second;
    });
    return result;
}

std::vector<Key> KeyCache::findByEMailAddress(const std::string &email) const
{
    return findByEMailAddress(email.c_str());
}

const Key &KeyCache::findByKeyIDOrFingerprint(const char *id) const
{
    {
        // try by.fpr first:
        const std::vector<Key>::const_iterator it = d->find_fpr(id);
        if (it != d->by.fpr.end()) {
            return *it;
        }
    }
    {
        // try by.keyid next:
        const std::vector<Key>::const_iterator it = d->find_keyid(id);
        if (it != d->by.keyid.end()) {
            return *it;
        }
    }
    static const Key null;
    return null;
}

const Key &KeyCache::findByKeyIDOrFingerprint(const std::string &id) const
{
    return findByKeyIDOrFingerprint(id.c_str());
}

std::vector<Key> KeyCache::findByKeyIDOrFingerprint(const std::vector<std::string> &ids) const
{
    std::vector<std::string> keyids;
    std::remove_copy_if(ids.begin(), ids.end(), std::back_inserter(keyids), [](const std::string &str) {
        return !str.c_str() || !*str.c_str();
    });

    // this is just case-insensitive string search:
    std::sort(keyids.begin(), keyids.end(), _detail::ByFingerprint<std::less>());

    std::vector<Key> result;
    result.reserve(keyids.size()); // dups shouldn't happen
    d->ensureCachePopulated();

    kdtools::set_intersection(d->by.fpr.begin(),
                              d->by.fpr.end(),
                              keyids.begin(),
                              keyids.end(),
                              std::back_inserter(result),
                              _detail::ByFingerprint<std::less>());
    if (result.size() < keyids.size()) {
        // note that By{Fingerprint,KeyID} define the same
        // order for _strings_
        kdtools::set_intersection(d->by.keyid.begin(),
                                  d->by.keyid.end(),
                                  keyids.begin(),
                                  keyids.end(),
                                  std::back_inserter(result),
                                  _detail::ByKeyID<std::less>());
    }
    // duplicates shouldn't happen, but make sure nonetheless:
    std::sort(result.begin(), result.end(), _detail::ByFingerprint<std::less>());
    result.erase(std::unique(result.begin(), result.end(), _detail::ByFingerprint<std::equal_to>()), result.end());

    // we skip looking into short key ids here, as it's highly
    // unlikely they're used for this purpose. We might need to revise
    // this decision, but only after testing.
    return result;
}

const Subkey &KeyCache::findSubkeyByKeyGrip(const char *grip, Protocol protocol) const
{
    static const Subkey null;
    d->ensureCachePopulated();
    const auto range = std::equal_range(d->by.keygrip.begin(), d->by.keygrip.end(), grip, _detail::ByKeyGrip<std::less>());
    if (range.first == range.second) {
        return null;
    } else if (protocol == UnknownProtocol) {
        return *range.first;
    } else {
        for (auto it = range.first; it != range.second; ++it) {
            if (it->parent().protocol() == protocol) {
                return *it;
            }
        }
    }
    return null;
}

const Subkey &KeyCache::findSubkeyByKeyGrip(const std::string &grip, Protocol protocol) const
{
    return findSubkeyByKeyGrip(grip.c_str(), protocol);
}

std::vector<GpgME::Subkey> Kleo::KeyCache::findSubkeysByKeyGrip(const char *grip, GpgME::Protocol protocol) const
{
    d->ensureCachePopulated();

    std::vector<GpgME::Subkey> subkeys;
    const auto range = std::equal_range(d->by.keygrip.begin(), d->by.keygrip.end(), grip, _detail::ByKeyGrip<std::less>());
    subkeys.reserve(std::distance(range.first, range.second));
    if (protocol == UnknownProtocol) {
        std::copy(range.first, range.second, std::back_inserter(subkeys));
    } else {
        std::copy_if(range.first, range.second, std::back_inserter(subkeys), [protocol](const auto &subkey) {
            return subkey.parent().protocol() == protocol;
        });
    }
    return subkeys;
}

std::vector<GpgME::Subkey> Kleo::KeyCache::findSubkeysByKeyGrip(const std::string &grip, GpgME::Protocol protocol) const
{
    return findSubkeysByKeyGrip(grip.c_str(), protocol);
}

std::vector<Subkey> KeyCache::findSubkeysByKeyID(const std::vector<std::string> &ids) const
{
    std::vector<std::string> sorted;
    sorted.reserve(ids.size());
    std::remove_copy_if(ids.begin(), ids.end(), std::back_inserter(sorted), [](const std::string &str) {
        return !str.c_str() || !*str.c_str();
    });

    std::sort(sorted.begin(), sorted.end(), _detail::ByKeyID<std::less>());

    std::vector<Subkey> result;
    d->ensureCachePopulated();
    kdtools::set_intersection(d->by.subkeyid.begin(),
                              d->by.subkeyid.end(),
                              sorted.begin(),
                              sorted.end(),
                              std::back_inserter(result),
                              _detail::ByKeyID<std::less>());
    return result;
}

const GpgME::Subkey &KeyCache::findSubkeyByFingerprint(const std::string &fpr) const
{
    static const Subkey null;

    const auto it = d->find_subkeyfpr(fpr.c_str());
    if (it != d->by.subkeyfpr.end()) {
        return *it;
    }
    return null;
}

std::vector<Key> KeyCache::findRecipients(const DecryptionResult &res) const
{
    std::vector<std::string> keyids;
    const auto recipients = res.recipients();
    for (const DecryptionResult::Recipient &r : recipients) {
        if (const char *kid = r.keyID()) {
            keyids.push_back(kid);
        }
    }
    const std::vector<Subkey> subkeys = findSubkeysByKeyID(keyids);
    std::vector<Key> result;
    result.reserve(subkeys.size());
    std::transform(subkeys.begin(), subkeys.end(), std::back_inserter(result), std::mem_fn(&Subkey::parent));

    std::sort(result.begin(), result.end(), _detail::ByFingerprint<std::less>());
    result.erase(std::unique(result.begin(), result.end(), _detail::ByFingerprint<std::equal_to>()), result.end());
    return result;
}

GpgME::Key KeyCache::findSigner(const GpgME::Signature &signature) const
{
    if (signature.isNull()) {
        return {};
    }

    GpgME::Key key = signature.key();
    if (key.isNull() && signature.fingerprint()) {
        key = findByFingerprint(signature.fingerprint());
    }
    if (key.isNull() && signature.fingerprint()) {
        // try to find a subkey that was used for signing
        const auto subkey = findSubkeyByFingerprint(signature.fingerprint());
        if (!subkey.isNull()) {
            key = subkey.parent();
        }
    }
    return key;
}

std::vector<Key> KeyCache::findSigners(const VerificationResult &res) const
{
    std::vector<Key> signers;
    if (res.numSignatures() > 0) {
        signers.reserve(res.numSignatures());
        Kleo::transform(res.signatures(), std::back_inserter(signers), [this](const auto &sig) {
            return findSigner(sig);
        });
    }
    return signers;
}

std::vector<Key> KeyCache::findSigningKeysByMailbox(const QString &mb) const
{
    return d->find_mailbox(mb, true);
}

std::vector<Key> KeyCache::findEncryptionKeysByMailbox(const QString &mb) const
{
    return d->find_mailbox(mb, false);
}

namespace
{
#define DO(op, meth, meth2)                                                                                                                                    \
    if (op key.meth()) {                                                                                                                                       \
    } else {                                                                                                                                                   \
        qDebug("rejecting for signing: %s: %s", #meth2, key.primaryFingerprint());                                                                             \
        return false;                                                                                                                                          \
    }
#define ACCEPT(meth) DO(!!, meth, !meth)
#define REJECT(meth) DO(!, meth, meth)
struct ready_for_signing {
    bool operator()(const Key &key) const
    {
        ACCEPT(hasSecret);
        ACCEPT(hasSign);
        REJECT(isRevoked);
        REJECT(isExpired);
        REJECT(isDisabled);
        REJECT(isInvalid);
        return true;
#undef DO
    }
};

#define DO(op, meth, meth2)                                                                                                                                    \
    if (op key.meth()) {                                                                                                                                       \
    } else {                                                                                                                                                   \
        qDebug("rejecting for encrypting: %s: %s", #meth2, key.primaryFingerprint());                                                                          \
        return false;                                                                                                                                          \
    }
struct ready_for_encryption {
    bool operator()(const Key &key) const
    {
        ACCEPT(hasEncrypt);
        REJECT(isRevoked);
        REJECT(isExpired);
        REJECT(isDisabled);
        REJECT(isInvalid);
        return true;
    }
#undef DO
#undef ACCEPT
#undef REJECT
};
}

std::vector<Key> KeyCache::Private::find_mailbox(const QString &email, bool sign) const
{
    if (email.isEmpty()) {
        return std::vector<Key>();
    }

    const auto pair = find_email(email.toUtf8().constData());
    std::vector<Key> result;
    result.reserve(std::distance(pair.first, pair.second));
    if (sign) {
        kdtools::copy_2nd_if(pair.first, pair.second, std::back_inserter(result), ready_for_signing());
    } else {
        kdtools::copy_2nd_if(pair.first, pair.second, std::back_inserter(result), ready_for_encryption());
    }

    return result;
}

std::vector<Key> KeyCache::findSubjects(const GpgME::Key &key, Options options) const
{
    if (key.isNull()) {
        return {};
    }

    return findSubjects(std::vector<Key>(1, key), options);
}

std::vector<Key> KeyCache::findSubjects(const std::vector<Key> &keys, Options options) const
{
    std::vector<Key> result;

    if (keys.empty()) {
        return result;
    }

    // get the immediate subjects
    for (const auto &key : keys) {
        const auto firstAndLastSubject = d->find_subjects(key.primaryFingerprint());
        result.insert(result.end(), firstAndLastSubject.first, firstAndLastSubject.second);
    }
    // remove duplicates
    _detail::sort_by_fpr(result);
    _detail::remove_duplicates_by_fpr(result);

    if (options & RecursiveSearch) {
        for (std::vector<Key> furtherSubjects = findSubjects(result, NoOption); //
             !furtherSubjects.empty();
             furtherSubjects = findSubjects(furtherSubjects, NoOption)) {
            std::vector<Key> combined;
            combined.reserve(result.size() + furtherSubjects.size());
            std::merge(result.begin(),
                       result.end(),
                       furtherSubjects.begin(),
                       furtherSubjects.end(),
                       std::back_inserter(combined),
                       _detail::ByFingerprint<std::less>());
            _detail::remove_duplicates_by_fpr(combined);
            if (result.size() == combined.size()) {
                // no new subjects were found; this happens if a chain has a cycle
                break;
            }
            result.swap(combined);
        }
    }

    return result;
}

std::vector<Key> KeyCache::findIssuers(const Key &key, Options options) const
{
    std::vector<Key> result;

    if (key.isNull()) {
        return result;
    }

    if (options & IncludeSubject) {
        result.push_back(key);
    }

    if (key.isRoot()) {
        return result;
    }

    Key issuer = findByFingerprint(key.chainID());

    if (issuer.isNull()) {
        return result;
    }

    result.push_back(issuer);

    if (!(options & RecursiveSearch)) {
        return result;
    }

    while (!issuer.isRoot()) {
        issuer = findByFingerprint(result.back().chainID());
        if (issuer.isNull()) {
            break;
        }
        const bool chainAlreadyContainsIssuer = Kleo::contains_if(result, [issuer](const auto &key) {
            return _detail::ByFingerprint<std::equal_to>()(issuer, key);
        });
        // we also add the issuer if the chain already contains it, so that
        // the user can spot the cycle
        result.push_back(issuer);
        if (chainAlreadyContainsIssuer) {
            // break on cycle in chain
            break;
        }
    }

    return result;
}

static std::string email(const UserID &uid)
{
    // Prefer the gnupg normalized one
    const std::string addr = uid.addrSpec();
    if (!addr.empty()) {
        return addr;
    }
    const std::string email = uid.email();
    if (email.empty()) {
        return DN(uid.id())[QStringLiteral("EMAIL")].trimmed().toUtf8().constData();
    }
    if (email[0] == '<' && email[email.size() - 1] == '>') {
        return email.substr(1, email.size() - 2);
    } else {
        return email;
    }
}

static std::vector<std::string> emails(const Key &key)
{
    std::vector<std::string> emails;
    const auto userIDs = key.userIDs();
    for (const UserID &uid : userIDs) {
        const std::string e = email(uid);
        if (!e.empty()) {
            emails.push_back(e);
        }
    }
    std::sort(emails.begin(), emails.end(), ByEMail<std::less>());
    emails.erase(std::unique(emails.begin(), emails.end(), ByEMail<std::equal_to>()), emails.end());
    return emails;
}

void KeyCache::remove(const Key &key)
{
    if (key.isNull()) {
        return;
    }

    const char *fpr = key.primaryFingerprint();
    if (!fpr) {
        return;
    }

    {
        const auto range = std::equal_range(d->by.fpr.begin(), d->by.fpr.end(), fpr, _detail::ByFingerprint<std::less>());
        d->by.fpr.erase(range.first, range.second);
    }

    if (const char *keyid = key.keyID()) {
        const auto range = std::equal_range(d->by.keyid.begin(), d->by.keyid.end(), keyid, _detail::ByKeyID<std::less>());
        const auto it = std::remove_if(range.first, range.second, [fpr](const GpgME::Key &key) {
            return _detail::ByFingerprint<std::equal_to>()(fpr, key);
        });
        d->by.keyid.erase(it, range.second);
    }

    if (const char *chainid = key.chainID()) {
        const auto range = std::equal_range(d->by.chainid.begin(), d->by.chainid.end(), chainid, _detail::ByChainID<std::less>());
        const auto range2 = std::equal_range(range.first, range.second, fpr, _detail::ByFingerprint<std::less>());
        d->by.chainid.erase(range2.first, range2.second);
    }

    const auto emailsKey{emails(key)};
    for (const std::string &email : emailsKey) {
        const auto range = std::equal_range(d->by.email.begin(), d->by.email.end(), email, ByEMail<std::less>());
        const auto it = std::remove_if(range.first, range.second, [fpr](const std::pair<std::string, Key> &pair) {
            return qstricmp(fpr, pair.second.primaryFingerprint()) == 0;
        });
        d->by.email.erase(it, range.second);
    }

    const auto keySubKeys{key.subkeys()};
    for (const Subkey &subkey : keySubKeys) {
        if (const char *subkeyfpr = subkey.fingerprint()) {
            const auto range = std::equal_range(d->by.subkeyfpr.begin(), d->by.subkeyfpr.end(), subkeyfpr, _detail::BySubkeyFingerprint<std::less>());
            const auto it = std::remove_if(range.first, range.second, [fpr](const Subkey &subkey) {
                return !qstricmp(fpr, subkey.parent().primaryFingerprint());
            });
            d->by.subkeyfpr.erase(it, range.second);
        }
        if (const char *keyid = subkey.keyID()) {
            const auto range = std::equal_range(d->by.subkeyid.begin(), d->by.subkeyid.end(), keyid, _detail::ByKeyID<std::less>());
            const auto it = std::remove_if(range.first, range.second, [fpr](const Subkey &subkey) {
                return !qstricmp(fpr, subkey.parent().primaryFingerprint());
            });
            d->by.subkeyid.erase(it, range.second);
        }
        if (const char *keygrip = subkey.keyGrip()) {
            const auto range = std::equal_range(d->by.keygrip.begin(), d->by.keygrip.end(), keygrip, _detail::ByKeyGrip<std::less>());
            const auto it = std::remove_if(range.first, range.second, [fpr](const Subkey &subkey) {
                return !qstricmp(fpr, subkey.parent().primaryFingerprint());
            });
            d->by.keygrip.erase(it, range.second);
        }
    }
}

void KeyCache::remove(const std::vector<Key> &keys)
{
    for (const Key &key : keys) {
        remove(key);
    }
}

const std::vector<GpgME::Key> &KeyCache::keys() const
{
    d->ensureCachePopulated();
    return d->by.fpr;
}

std::vector<Key> KeyCache::secretKeys() const
{
    std::vector<Key> keys = this->keys();
    keys.erase(std::remove_if(keys.begin(),
                              keys.end(),
                              [](const Key &key) {
                                  return !key.hasSecret();
                              }),
               keys.end());
    return keys;
}

KeyGroup KeyCache::group(const QString &id) const
{
    KeyGroup result{};
    const auto it = std::find_if(std::cbegin(d->m_groups), std::cend(d->m_groups), [id](const auto &g) {
        return g.id() == id;
    });
    if (it != std::cend(d->m_groups)) {
        result = *it;
    }
    return result;
}

std::vector<KeyGroup> KeyCache::groups() const
{
    d->ensureCachePopulated();
    return d->m_groups;
}

std::vector<KeyGroup> KeyCache::configurableGroups() const
{
    std::vector<KeyGroup> groups;
    groups.reserve(d->m_groups.size());
    std::copy_if(d->m_groups.cbegin(), d->m_groups.cend(), std::back_inserter(groups), [](const KeyGroup &group) {
        return group.source() == KeyGroup::ApplicationConfig;
    });
    return groups;
}

namespace
{
bool compareById(const KeyGroup &lhs, const KeyGroup &rhs)
{
    return lhs.id() < rhs.id();
}

std::vector<KeyGroup> sortedById(std::vector<KeyGroup> groups)
{
    std::sort(groups.begin(), groups.end(), &compareById);
    return groups;
}
}

void KeyCache::saveConfigurableGroups(const std::vector<KeyGroup> &groups)
{
    const std::vector<KeyGroup> oldGroups = sortedById(configurableGroups());
    const std::vector<KeyGroup> newGroups = sortedById(groups);

    {
        std::vector<KeyGroup> removedGroups;
        std::set_difference(oldGroups.begin(), oldGroups.end(), newGroups.begin(), newGroups.end(), std::back_inserter(removedGroups), &compareById);
        for (const auto &group : std::as_const(removedGroups)) {
            qCDebug(LIBKLEO_LOG) << "Removing group" << group;
            d->remove(group);
        }
    }
    {
        std::vector<KeyGroup> updatedGroups;
        std::set_intersection(newGroups.begin(), newGroups.end(), oldGroups.begin(), oldGroups.end(), std::back_inserter(updatedGroups), &compareById);
        for (const auto &group : std::as_const(updatedGroups)) {
            qCDebug(LIBKLEO_LOG) << "Updating group" << group;
            d->update(group);
        }
    }
    {
        std::vector<KeyGroup> addedGroups;
        std::set_difference(newGroups.begin(), newGroups.end(), oldGroups.begin(), oldGroups.end(), std::back_inserter(addedGroups), &compareById);
        for (const auto &group : std::as_const(addedGroups)) {
            qCDebug(LIBKLEO_LOG) << "Adding group" << group;
            d->insert(group);
        }
    }

    Q_EMIT keysMayHaveChanged();
}

bool KeyCache::insert(const KeyGroup &group)
{
    if (!d->insert(group)) {
        return false;
    }

    Q_EMIT keysMayHaveChanged();

    return true;
}

bool KeyCache::update(const KeyGroup &group)
{
    if (!d->update(group)) {
        return false;
    }

    Q_EMIT keysMayHaveChanged();

    return true;
}

bool KeyCache::remove(const KeyGroup &group)
{
    if (!d->remove(group)) {
        return false;
    }

    Q_EMIT keysMayHaveChanged();

    return true;
}

void KeyCache::refresh(const std::vector<Key> &keys)
{
    // make this better...
    clear();
    insert(keys);
}

void KeyCache::insert(const Key &key)
{
    insert(std::vector<Key>(1, key));
}

namespace
{

template<template<template<typename T> class Op> class T1, template<template<typename T> class Op> class T2>
struct lexicographically {
    using result_type = bool;

    template<typename U, typename V>
    bool operator()(const U &lhs, const V &rhs) const
    {
        return T1<std::less>()(lhs, rhs) //
            || (T1<std::equal_to>()(lhs, rhs) && T2<std::less>()(lhs, rhs));
    }
};

}

void KeyCache::insert(const std::vector<Key> &keys)
{
    // 1. filter out keys with empty fingerprints:
    std::vector<Key> sorted;
    sorted.reserve(keys.size());
    std::copy_if(keys.begin(), keys.end(), std::back_inserter(sorted), [](const Key &key) {
        auto fp = key.primaryFingerprint();
        return fp && *fp;
    });

    // this is sub-optimal, but makes implementation from here on much easier
    remove(sorted);

    // 2. sort by fingerprint:
    std::sort(sorted.begin(), sorted.end(), _detail::ByFingerprint<std::less>());

    // 2a. insert into fpr index:
    std::vector<Key> by_fpr;
    by_fpr.reserve(sorted.size() + d->by.fpr.size());
    std::merge(sorted.begin(), sorted.end(), d->by.fpr.begin(), d->by.fpr.end(), std::back_inserter(by_fpr), _detail::ByFingerprint<std::less>());

    // 3. build email index:
    std::vector<std::pair<std::string, Key>> pairs;
    pairs.reserve(sorted.size());
    for (const Key &key : std::as_const(sorted)) {
        const std::vector<std::string> emails = ::emails(key);
        for (const std::string &e : emails) {
            pairs.push_back(std::make_pair(e, key));
        }
    }
    std::sort(pairs.begin(), pairs.end(), ByEMail<std::less>());

    // 3a. insert into email index:
    std::vector<std::pair<std::string, Key>> by_email;
    by_email.reserve(pairs.size() + d->by.email.size());
    std::merge(pairs.begin(), pairs.end(), d->by.email.begin(), d->by.email.end(), std::back_inserter(by_email), ByEMail<std::less>());

    // 3.5: stable-sort by chain-id (effectively lexicographically<ByChainID,ByFingerprint>)
    std::stable_sort(sorted.begin(), sorted.end(), _detail::ByChainID<std::less>());

    // 3.5a: insert into chain-id index:
    std::vector<Key> nonroot;
    nonroot.reserve(sorted.size());
    std::vector<Key> by_chainid;
    by_chainid.reserve(sorted.size() + d->by.chainid.size());
    std::copy_if(sorted.cbegin(), sorted.cend(), std::back_inserter(nonroot), [](const Key &key) {
        return !key.isRoot();
    });
    std::merge(nonroot.cbegin(),
               nonroot.cend(),
               d->by.chainid.cbegin(),
               d->by.chainid.cend(),
               std::back_inserter(by_chainid),
               lexicographically<_detail::ByChainID, _detail::ByFingerprint>());

    // 4. sort by key id:
    std::sort(sorted.begin(), sorted.end(), _detail::ByKeyID<std::less>());

    // 4a. insert into keyid index:
    std::vector<Key> by_keyid;
    by_keyid.reserve(sorted.size() + d->by.keyid.size());
    std::merge(sorted.begin(), sorted.end(), d->by.keyid.begin(), d->by.keyid.end(), std::back_inserter(by_keyid), _detail::ByKeyID<std::less>());

    // 5. has been removed

    // 6. build subkey ID index:
    std::vector<Subkey> subkeys;
    subkeys.reserve(sorted.size());
    for (const Key &key : std::as_const(sorted)) {
        const auto keySubkeys{key.subkeys()};
        for (const Subkey &subkey : keySubkeys) {
            if (subkey.canRenc()) {
                continue;
            }
            subkeys.push_back(subkey);
        }
    }

    // 6a sort by key id:
    std::sort(subkeys.begin(), subkeys.end(), _detail::ByKeyID<std::less>());

    // 6b. insert into subkey ID index:
    std::vector<Subkey> by_subkeyid;
    by_subkeyid.reserve(subkeys.size() + d->by.subkeyid.size());
    std::merge(subkeys.begin(), subkeys.end(), d->by.subkeyid.begin(), d->by.subkeyid.end(), std::back_inserter(by_subkeyid), _detail::ByKeyID<std::less>());

    // 6c. sort by key grip
    std::sort(subkeys.begin(), subkeys.end(), _detail::ByKeyGrip<std::less>());

    // 6d. insert into subkey keygrip index:
    std::vector<Subkey> by_keygrip;
    by_keygrip.reserve(subkeys.size() + d->by.keygrip.size());
    std::merge(subkeys.begin(), subkeys.end(), d->by.keygrip.begin(), d->by.keygrip.end(), std::back_inserter(by_keygrip), _detail::ByKeyGrip<std::less>());

    // 6e sort by fingerprint:
    std::sort(subkeys.begin(), subkeys.end(), _detail::BySubkeyFingerprint<std::less>());

    // 6f. insert into subkey fingerprint index:
    std::vector<Subkey> by_subkeyfpr;
    by_subkeyfpr.reserve(subkeys.size() + d->by.subkeyfpr.size());
    std::merge(subkeys.begin(),
               subkeys.end(),
               d->by.subkeyfpr.begin(),
               d->by.subkeyfpr.end(),
               std::back_inserter(by_subkeyfpr),
               _detail::BySubkeyFingerprint<std::less>());

    // now commit (well, we already removed keys...)
    by_fpr.swap(d->by.fpr);
    by_keyid.swap(d->by.keyid);
    by_email.swap(d->by.email);
    by_subkeyfpr.swap(d->by.subkeyfpr);
    by_subkeyid.swap(d->by.subkeyid);
    by_keygrip.swap(d->by.keygrip);
    by_chainid.swap(d->by.chainid);

    for (const Key &key : std::as_const(sorted)) {
        d->m_pgpOnly &= key.protocol() == GpgME::OpenPGP;
    }

    d->m_cards.clear();
    for (const auto &key : keys) {
        for (const auto &subkey : key.subkeys()) {
            if (!subkey.isSecret() || !d->m_cards[QByteArray(subkey.keyGrip())].empty()) {
                continue;
            }
            const auto data = readSecretKeyFile(QString::fromLatin1(subkey.keyGrip()));
            for (const auto &line : data) {
                if (line.startsWith(QByteArrayLiteral("Token"))) {
                    const auto split = line.split(' ');
                    if (split.size() > 2) {
                        const auto keyRef = QString::fromUtf8(split[2]).trimmed();
                        d->m_cards[QByteArray(subkey.keyGrip())].push_back(CardKeyStorageInfo{
                            QString::fromUtf8(split[1]),
                            split.size() > 4 ? QString::fromLatin1(
                                QString::fromUtf8(split[4]).trimmed().replace(QLatin1Char('+'), QLatin1Char(' ')).toUtf8().percentDecoded())
                                             : QString(),
                            keyRef,
                        });
                    }
                }
            }
        }
    }

    Q_EMIT keysMayHaveChanged();
}

void KeyCache::clear()
{
    d->by = Private::By();
}

//
//
// RefreshKeysJob
//
//

class KeyCache::RefreshKeysJob::Private
{
    RefreshKeysJob *const q;

public:
    Private(KeyCache *cache, RefreshKeysJob *qq);
    void doStart();
    Error startKeyListing(GpgME::Protocol protocol);
    void listAllKeysJobDone(const KeyListResult &res, const std::vector<Key> &nextKeys)
    {
        if (!nextKeys.empty()) {
            std::vector<Key> keys;
            keys.reserve(m_keys.size() + nextKeys.size());
            if (m_keys.empty()) {
                keys = nextKeys;
            } else {
                std::merge(m_keys.begin(), m_keys.end(), nextKeys.begin(), nextKeys.end(), std::back_inserter(keys), _detail::ByFingerprint<std::less>());
            }
            m_keys.swap(keys);
        }
        jobDone(res);
    }
    void emitDone(const KeyListResult &result);
    void updateKeyCache();

    QPointer<KeyCache> m_cache;
    QList<QGpgME::ListAllKeysJob *> m_jobsPending;
    std::vector<Key> m_keys;
    KeyListResult m_mergedResult;
    bool m_canceled;

private:
    void jobDone(const KeyListResult &res);
};

KeyCache::RefreshKeysJob::Private::Private(KeyCache *cache, RefreshKeysJob *qq)
    : q(qq)
    , m_cache(cache)
    , m_canceled(false)
{
    Q_ASSERT(m_cache);
}

void KeyCache::RefreshKeysJob::Private::jobDone(const KeyListResult &result)
{
    if (m_canceled) {
        q->deleteLater();
        return;
    }

    QObject *const sender = q->sender();
    if (sender) {
        sender->disconnect(q);
    }
    Q_ASSERT(!m_jobsPending.empty());
    m_jobsPending.removeOne(qobject_cast<QGpgME::ListAllKeysJob *>(sender));
    m_mergedResult.mergeWith(result);
    if (!m_jobsPending.empty()) {
        return;
    }
    updateKeyCache();
    emitDone(m_mergedResult);
}

void KeyCache::RefreshKeysJob::Private::emitDone(const KeyListResult &res)
{
    q->deleteLater();
    Q_EMIT q->done(res);
}

KeyCache::RefreshKeysJob::RefreshKeysJob(KeyCache *cache, QObject *parent)
    : QObject(parent)
    , d(new Private(cache, this))
{
}

KeyCache::RefreshKeysJob::~RefreshKeysJob()
{
    delete d;
}

void KeyCache::RefreshKeysJob::start()
{
    qCDebug(LIBKLEO_LOG) << "KeyCache::RefreshKeysJob" << __func__;
    QTimer::singleShot(0, this, [this]() {
        d->doStart();
    });
}

void KeyCache::RefreshKeysJob::cancel()
{
    d->m_canceled = true;
    std::for_each(d->m_jobsPending.begin(), d->m_jobsPending.end(), std::mem_fn(&QGpgME::ListAllKeysJob::slotCancel));
    Q_EMIT canceled();
}

void KeyCache::RefreshKeysJob::Private::doStart()
{
    if (m_canceled) {
        q->deleteLater();
        return;
    }

    Q_ASSERT(m_jobsPending.empty());
    m_mergedResult.mergeWith(KeyListResult(startKeyListing(GpgME::OpenPGP)));
    m_mergedResult.mergeWith(KeyListResult(startKeyListing(GpgME::CMS)));

    if (!m_jobsPending.empty()) {
        return;
    }

    const bool hasError = m_mergedResult.error() || m_mergedResult.error().isCanceled();
    emitDone(hasError ? m_mergedResult : KeyListResult(Error(GPG_ERR_UNSUPPORTED_OPERATION)));
}

void KeyCache::RefreshKeysJob::Private::updateKeyCache()
{
    if (!m_cache || m_canceled) {
        q->deleteLater();
        return;
    }

    std::vector<Key> cachedKeys = m_cache->initialized() ? m_cache->keys() : std::vector<Key>();
    std::sort(cachedKeys.begin(), cachedKeys.end(), _detail::ByFingerprint<std::less>());
    std::vector<Key> keysToRemove;
    std::set_difference(cachedKeys.begin(),
                        cachedKeys.end(),
                        m_keys.begin(),
                        m_keys.end(),
                        std::back_inserter(keysToRemove),
                        _detail::ByFingerprint<std::less>());
    m_cache->remove(keysToRemove);
    m_cache->refresh(m_keys);
}

Error KeyCache::RefreshKeysJob::Private::startKeyListing(GpgME::Protocol proto)
{
    const auto *const protocol = (proto == GpgME::OpenPGP) ? QGpgME::openpgp() : QGpgME::smime();
    if (!protocol) {
        return Error();
    }
    QGpgME::ListAllKeysJob *const job = protocol->listAllKeysJob(/*includeSigs*/ false, /*validate*/ true);
    if (!job) {
        return Error();
    }
    if (!m_cache->initialized()) {
        // avoid delays during the initial key listing
        job->setOptions(QGpgME::ListAllKeysJob::DisableAutomaticTrustDatabaseCheck);
    }

#if 0
    aheinecke: 2017.01.12:

    For unknown reasons the new style connect fails at runtime
    over library borders into QGpgME from the GpgME repo
    when cross compiled for Windows and default arguments
    are used in the Signal.

    This was tested with gcc 4.9 (Mingw 3.0.2) and we could not
    find an explanation for this. So until this is fixed or we understand
    the problem we need to use the old style connect for QGpgME signals.

    The new style connect of the canceled signal right below
    works fine.

    connect(job, &QGpgME::ListAllKeysJob::result,
            q, [this](const GpgME::KeyListResult &res, const std::vector<GpgME::Key> &keys) {
                listAllKeysJobDone(res, keys);
            });
#endif
    connect(job, SIGNAL(result(GpgME::KeyListResult, std::vector<GpgME::Key>)), q, SLOT(listAllKeysJobDone(GpgME::KeyListResult, std::vector<GpgME::Key>)));

    connect(q, &RefreshKeysJob::canceled, job, &QGpgME::Job::slotCancel);

    // Only do this for initialized keycaches to avoid huge waits for
    // signature notations during initial keylisting.
    if (proto == GpgME::OpenPGP && m_cache->remarksEnabled() && m_cache->initialized()) {
        auto ctx = QGpgME::Job::context(job);
        if (ctx) {
            ctx->addKeyListMode(KeyListMode::Signatures | KeyListMode::SignatureNotations);
        }
    }

    const Error error = job->start(true);

    if (!error && !error.isCanceled()) {
        m_jobsPending.push_back(job);
    }
    return error;
}

bool KeyCache::initialized() const
{
    return d->m_initalized;
}

void KeyCache::Private::ensureCachePopulated() const
{
    if (!m_initalized) {
        q->startKeyListing();
        QEventLoop loop;
        loop.connect(q, &KeyCache::keyListingDone, &loop, &QEventLoop::quit);
        qCDebug(LIBKLEO_LOG) << "Waiting for keycache.";
        loop.exec();
        qCDebug(LIBKLEO_LOG) << "Keycache available.";
    }
}

bool KeyCache::pgpOnly() const
{
    return d->m_pgpOnly;
}

static bool keyIsOk(const Key &k)
{
    return !k.isExpired() && !k.isRevoked() && !k.isInvalid() && !k.isDisabled();
}

static bool uidIsOk(const UserID &uid)
{
    return keyIsOk(uid.parent()) && !uid.isRevoked() && !uid.isInvalid();
}

static bool subkeyIsOk(const Subkey &s)
{
    return !s.isRevoked() && !s.isInvalid() && !s.isDisabled();
}

namespace
{
time_t creationTimeOfNewestSuitableSubKey(const Key &key, KeyCache::KeyUsage usage)
{
    time_t creationTime = 0;
    for (const Subkey &s : key.subkeys()) {
        if (!subkeyIsOk(s)) {
            continue;
        }
        if (usage == KeyCache::KeyUsage::Sign && !s.canSign()) {
            continue;
        }
        if (usage == KeyCache::KeyUsage::Encrypt && !s.canEncrypt()) {
            continue;
        }
        if (s.creationTime() > creationTime) {
            creationTime = s.creationTime();
        }
    }
    return creationTime;
}

struct BestMatch {
    Key key;
    UserID uid;
    time_t creationTime = 0;
};
}

GpgME::Key KeyCache::findBestByMailBox(const char *addr, GpgME::Protocol proto, KeyUsage usage) const
{
    d->ensureCachePopulated();
    if (!addr) {
        return {};
    }

    // support lookup of email addresses enclosed in angle brackets
    QByteArray address(addr);
    if (address.size() > 1 && address[0] == '<' && address[address.size() - 1] == '>') {
        address = address.mid(1, address.size() - 2);
    }
    address = address.toLower();

    BestMatch best;
    for (const Key &k : findByEMailAddress(address.constData())) {
        if (proto != Protocol::UnknownProtocol && k.protocol() != proto) {
            continue;
        }
        if (usage == KeyUsage::Encrypt && !keyHasEncrypt(k)) {
            continue;
        }
        if (usage == KeyUsage::Sign && (!keyHasSign(k) || !k.hasSecret())) {
            continue;
        }
        const time_t creationTime = creationTimeOfNewestSuitableSubKey(k, usage);
        if (creationTime == 0) {
            // key does not have a suitable (and usable) subkey
            continue;
        }
        for (const UserID &u : k.userIDs()) {
            if (QByteArray::fromStdString(u.addrSpec()).toLower() != address) {
                // user ID does not match the given email address
                continue;
            }
            if (best.uid.isNull()) {
                // we have found our first candidate
                best = {k, u, creationTime};
            } else if (!uidIsOk(best.uid) && uidIsOk(u)) {
                // validity of the new key is better
                best = {k, u, creationTime};
            } else if (!k.isExpired() && best.uid.validity() < u.validity()) {
                // validity of the new key is better
                best = {k, u, creationTime};
            } else if (best.key.isExpired() && !k.isExpired()) {
                // validity of the new key is better
                best = {k, u, creationTime};
            } else if (best.uid.validity() == u.validity() && uidIsOk(u) && best.creationTime < creationTime) {
                // both keys/user IDs have same validity, but the new key is newer
                best = {k, u, creationTime};
            }
        }
    }

    return best.key;
}

namespace
{
template<typename T>
bool allKeysAllowUsage(const T &keys, KeyCache::KeyUsage usage)
{
    switch (usage) {
    case KeyCache::KeyUsage::AnyUsage:
        return true;
    case KeyCache::KeyUsage::Sign:
        return std::all_of(std::begin(keys), std::end(keys), std::mem_fn(&Key::hasSign));
    case KeyCache::KeyUsage::Encrypt:
        return std::all_of(std::begin(keys), std::end(keys), std::mem_fn(&Key::hasEncrypt));
    case KeyCache::KeyUsage::Certify:
        return std::all_of(std::begin(keys), std::end(keys), std::mem_fn(&Key::hasCertify));
    case KeyCache::KeyUsage::Authenticate:
        return std::all_of(std::begin(keys), std::end(keys), std::mem_fn(&Key::hasAuthenticate));
    }
    qCDebug(LIBKLEO_LOG) << __func__ << "called with invalid usage" << int(usage);
    return false;
}
}

KeyGroup KeyCache::findGroup(const QString &name, Protocol protocol, KeyUsage usage) const
{
    d->ensureCachePopulated();

    Q_ASSERT(usage == KeyUsage::Sign || usage == KeyUsage::Encrypt);
    for (const auto &group : std::as_const(d->m_groups)) {
        if (group.name() == name) {
            const KeyGroup::Keys &keys = group.keys();
            if (allKeysAllowUsage(keys, usage) && (protocol == UnknownProtocol || allKeysHaveProtocol(keys, protocol))) {
                return group;
            }
        }
    }

    return {};
}

std::vector<Key> KeyCache::getGroupKeys(const QString &groupName) const
{
    std::vector<Key> result;
    for (const KeyGroup &g : std::as_const(d->m_groups)) {
        if (g.name() == groupName) {
            const KeyGroup::Keys &keys = g.keys();
            std::copy(keys.cbegin(), keys.cend(), std::back_inserter(result));
        }
    }
    _detail::sort_by_fpr(result);
    _detail::remove_duplicates_by_fpr(result);
    return result;
}

void KeyCache::setKeys(const std::vector<GpgME::Key> &keys)
{
    // disable regular key listing and cancel running key listing
    setRefreshInterval(0);
    cancelKeyListing();
    clear();
    insert(keys);
    d->m_initalized = true;
    Q_EMIT keyListingDone(KeyListResult());
}

void KeyCache::setGroups(const std::vector<KeyGroup> &groups)
{
    Q_ASSERT(d->m_initalized && "Call setKeys() before setting groups");
    d->m_groups = groups;
    Q_EMIT keysMayHaveChanged();
}

std::vector<CardKeyStorageInfo> KeyCache::cardsForSubkey(const GpgME::Subkey &subkey) const
{
    return d->m_cards[QByteArray(subkey.keyGrip())];
}

#include "moc_keycache.cpp"
#include "moc_keycache_p.cpp"
