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

    This file is part of Kleopatra, the KDE keymanager
    Copyright (c) 2008 Klarälvdalens Datakonsult AB

    Kleopatra is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    Kleopatra is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

    In addition, as a special exception, the copyright holders give
    permission to link the code of this program with any edition of
    the Qt library by Trolltech AS, Norway (or with modified versions
    of Qt that use the same license as Qt), and distribute linked
    combinations including the two.  You must obey the GNU General
    Public License in all respects for all of the code used other than
    Qt.  If you modify this file, you may extend this exception to
    your version of the file, but you are not obligated to do so.  If
    you do not wish to do so, delete this exception statement from
    your version.
*/

#include <config-kleopatra.h>
#include "kleopatra_debug.h"
#include "decryptverifyemailcontroller.h"

#include "emailoperationspreferences.h"

#include <crypto/gui/newresultpage.h>
#include <crypto/decryptverifytask.h>
#include <crypto/taskcollection.h>

#include <utils/classify.h>
#include <utils/formatting.h>
#include <utils/gnupg-helper.h>
#include <utils/input.h>
#include <utils/output.h>
#include <utils/kleo_assert.h>

#include <Libkleo/CryptoBackendFactory>

#include <kmime/kmime_header_parsing.h>

#include <KLocalizedString>

#include <QPoint>
#include <QPointer>
#include <QTimer>

#include <boost/shared_ptr.hpp>

#include <memory>
#include <vector>

using namespace boost;
using namespace GpgME;
using namespace Kleo;
using namespace Kleo::Crypto;
using namespace Kleo::Crypto::Gui;
using namespace KMime::Types;

namespace
{

class DecryptVerifyEMailWizard : public QWizard
{
    Q_OBJECT
public:
    explicit DecryptVerifyEMailWizard(QWidget *parent = Q_NULLPTR, Qt::WindowFlags f = 0)
        : QWizard(parent, f),
          m_resultPage(this)
    {
        KDAB_SET_OBJECT_NAME(m_resultPage);

        m_resultPage.setSubTitle(i18n("Status and progress of the crypto operations is shown here."));
        // there's no way we're letting users fast-forward over the decryption/verification results...
        m_resultPage.setKeepOpenWhenDoneShown(false);

        addPage(&m_resultPage);
    }

    void addTaskCollection(const shared_ptr<TaskCollection> &coll)
    {
        m_resultPage.addTaskCollection(coll);
    }

public Q_SLOTS:
    void accept() Q_DECL_OVERRIDE {
        EMailOperationsPreferences prefs;
        prefs.setDecryptVerifyPopupGeometry(geometry());
        prefs.save();
        QWizard::accept();
    }

private:
    NewResultPage m_resultPage;
};

}

class DecryptVerifyEMailController::Private
{
    DecryptVerifyEMailController *const q;
public:

    explicit Private(DecryptVerifyEMailController *qq);

    void slotWizardCanceled();
    void schedule();

    std::vector<shared_ptr<AbstractDecryptVerifyTask> > buildTasks();

    static DecryptVerifyEMailWizard *findOrCreateWizard(unsigned int id);

    void ensureWizardCreated();
    void ensureWizardVisible();
    void reportError(int err, const QString &details)
    {
        q->setLastError(err, details);
        q->emitDoneOrError();
    }

    void cancelAllTasks();

    std::vector<shared_ptr<Input> > m_inputs, m_signedDatas;
    std::vector<shared_ptr<Output> > m_outputs;

    unsigned int m_sessionId;
    QPointer<DecryptVerifyEMailWizard> m_wizard;
    std::vector<shared_ptr<const DecryptVerifyResult> > m_results;
    std::vector<shared_ptr<AbstractDecryptVerifyTask> > m_runnableTasks, m_completedTasks;
    shared_ptr<AbstractDecryptVerifyTask> m_runningTask;
    bool m_silent;
    bool m_operationCompleted;
    DecryptVerifyOperation m_operation;
    Protocol m_protocol;
    VerificationMode m_verificationMode;
    std::vector<KMime::Types::Mailbox> m_informativeSenders;
};

DecryptVerifyEMailController::Private::Private(DecryptVerifyEMailController *qq)
    : q(qq),
      m_sessionId(0),
      m_silent(false),
      m_operationCompleted(false),
      m_operation(DecryptVerify),
      m_protocol(UnknownProtocol),
      m_verificationMode(Detached)
{
    qRegisterMetaType<VerificationResult>();
}

void DecryptVerifyEMailController::Private::slotWizardCanceled()
{
    qCDebug(KLEOPATRA_LOG);
    if (!m_operationCompleted) {
        reportError(gpg_error(GPG_ERR_CANCELED), i18n("User canceled"));
    }
}

void DecryptVerifyEMailController::doTaskDone(const Task *task, const shared_ptr<const Task::Result> &result)
{
    assert(task);

    // We could just delete the tasks here, but we can't use
    // Qt::QueuedConnection here (we need sender()) and other slots
    // might not yet have executed. Therefore, we push completed tasks
    // into a burial container

    if (task == d->m_runningTask.get()) {
        d->m_completedTasks.push_back(d->m_runningTask);
        const shared_ptr<const DecryptVerifyResult> &dvr = boost::dynamic_pointer_cast<const DecryptVerifyResult>(result);
        assert(dvr);
        d->m_results.push_back(dvr);
        d->m_runningTask.reset();
    }

    QTimer::singleShot(0, this, SLOT(schedule()));

}

void DecryptVerifyEMailController::Private::schedule()
{
    if (!m_runningTask && !m_runnableTasks.empty()) {
        const shared_ptr<AbstractDecryptVerifyTask> t = m_runnableTasks.back();
        m_runnableTasks.pop_back();
        t->start();
        m_runningTask = t;
    }
    if (!m_runningTask) {
        kleo_assert(m_runnableTasks.empty());
        Q_FOREACH (const shared_ptr<const DecryptVerifyResult> &i, m_results) {
            Q_EMIT q->verificationResult(i->verificationResult());
        }
        // if there is a popup, wait for either the client cancel or the user closing the popup.
        // Otherwise (silent case), finish immediately
        m_operationCompleted = true;
        q->emitDoneOrError();
    }
}

void DecryptVerifyEMailController::Private::ensureWizardCreated()
{
    if (m_wizard) {
        return;
    }

    DecryptVerifyEMailWizard *w = findOrCreateWizard(m_sessionId);
    connect(w, SIGNAL(destroyed()), q, SLOT(slotWizardCanceled()), Qt::QueuedConnection);
    m_wizard = w;

}

namespace
{
template <typename C>
void collectGarbage(C &c)
{
    typename C::iterator it = c.begin();
    while (it != c.end() /*sic!*/)
        if (it->second) {
            ++it;
        } else {
            c.erase(it++ /*sic!*/);
        }
}
}

// static
DecryptVerifyEMailWizard *DecryptVerifyEMailController::Private::findOrCreateWizard(unsigned int id)
{

    static std::map<unsigned int, QPointer<DecryptVerifyEMailWizard> > s_wizards;

    collectGarbage(s_wizards);

    qCDebug(KLEOPATRA_LOG) << "id = " << id;

    if (id != 0) {

        const std::map<unsigned int, QPointer<DecryptVerifyEMailWizard> >::const_iterator it
            = s_wizards.find(id);

        if (it != s_wizards.end()) {
            assert(it->second && "This should have been garbage-collected");
            return it->second;
        }

    }

    DecryptVerifyEMailWizard *w = new DecryptVerifyEMailWizard;
    w->setWindowTitle(i18n("Decrypt/Verify E-Mail"));
    w->setAttribute(Qt::WA_DeleteOnClose);

    const QRect preferredGeometry = EMailOperationsPreferences().decryptVerifyPopupGeometry();
    if (preferredGeometry.isValid()) {
        w->setGeometry(preferredGeometry);
    }

    s_wizards[id] = w;

    return w;
}

std::vector< shared_ptr<AbstractDecryptVerifyTask> > DecryptVerifyEMailController::Private::buildTasks()
{
    const uint numInputs = m_inputs.size();
    const uint numMessages = m_signedDatas.size();
    const uint numOutputs = m_outputs.size();
    const uint numInformativeSenders = m_informativeSenders.size();

    // these are duplicated from DecryptVerifyCommandEMailBase::Private::checkForErrors with slightly modified error codes/messages
    if (!numInputs)
        throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),
                              i18n("At least one input needs to be provided"));

    if (numInformativeSenders > 0 && numInformativeSenders != numInputs)
        throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),     //TODO use better error code if possible
                              i18n("Informative sender/signed data count mismatch"));

    if (numMessages) {
        if (numMessages != numInputs)
            throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),     //TODO use better error code if possible
                                  i18n("Signature/signed data count mismatch"));
        else if (m_operation != Verify || m_verificationMode != Detached)
            throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),
                                  i18n("Signed data can only be given for detached signature verification"));
    }

    if (numOutputs) {
        if (numOutputs != numInputs)
            throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),    //TODO use better error code if possible
                                  i18n("Input/Output count mismatch"));
        else if (numMessages)
            throw Kleo::Exception(makeGnuPGError(GPG_ERR_CONFLICT),
                                  i18n("Cannot use output and signed data simultaneously"));
    }

    kleo_assert(m_protocol != UnknownProtocol);

    const CryptoBackend::Protocol *const backend = CryptoBackendFactory::instance()->protocol(m_protocol);
    if (!backend) {
        throw Kleo::Exception(makeGnuPGError(GPG_ERR_UNSUPPORTED_PROTOCOL), i18n("No backend support for %1", Formatting::displayName(m_protocol)));
    }

    if (m_operation != Decrypt && !m_silent) {
        ensureWizardVisible();
    }

    std::vector< shared_ptr<AbstractDecryptVerifyTask> > tasks;

    for (unsigned int i = 0; i < numInputs; ++i) {
        shared_ptr<AbstractDecryptVerifyTask> task;
        switch (m_operation) {
        case Decrypt: {
            shared_ptr<DecryptTask> t(new DecryptTask);
            t->setInput(m_inputs.at(i));
            assert(numOutputs);
            t->setOutput(m_outputs.at(i));
            t->setProtocol(m_protocol);
            task = t;
        }
        break;
        case Verify: {
            if (m_verificationMode == Detached) {
                shared_ptr<VerifyDetachedTask> t(new VerifyDetachedTask);
                t->setInput(m_inputs.at(i));
                t->setSignedData(m_signedDatas.at(i));
                if (numInformativeSenders > 0) {
                    t->setInformativeSender(m_informativeSenders.at(i));
                }
                t->setProtocol(m_protocol);
                task = t;
            } else {
                shared_ptr<VerifyOpaqueTask> t(new VerifyOpaqueTask);
                t->setInput(m_inputs.at(i));
                if (numOutputs) {
                    t->setOutput(m_outputs.at(i));
                }
                if (numInformativeSenders > 0) {
                    t->setInformativeSender(m_informativeSenders.at(i));
                }
                t->setProtocol(m_protocol);
                task = t;
            }
        }
        break;
        case DecryptVerify: {
            shared_ptr<DecryptVerifyTask> t(new DecryptVerifyTask);
            t->setInput(m_inputs.at(i));
            assert(numOutputs);
            t->setOutput(m_outputs.at(i));
            if (numInformativeSenders > 0) {
                t->setInformativeSender(m_informativeSenders.at(i));
            }
            t->setProtocol(m_protocol);
            task = t;
        }
        }

        assert(task);
        tasks.push_back(task);
    }

    return tasks;
}

void DecryptVerifyEMailController::Private::ensureWizardVisible()
{
    ensureWizardCreated();
    q->bringToForeground(m_wizard);
}

DecryptVerifyEMailController::DecryptVerifyEMailController(QObject *parent) : Controller(parent), d(new Private(this))
{
}

DecryptVerifyEMailController::DecryptVerifyEMailController(const shared_ptr<const ExecutionContext> &ctx, QObject *parent) : Controller(ctx, parent), d(new Private(this))
{
}

DecryptVerifyEMailController::~DecryptVerifyEMailController()
{
    qCDebug(KLEOPATRA_LOG);
}

void DecryptVerifyEMailController::start()
{
    d->m_runnableTasks = d->buildTasks();

    const shared_ptr<TaskCollection> coll(new TaskCollection);
    std::vector<shared_ptr<Task> > tsks;
    Q_FOREACH (const shared_ptr<Task> &i, d->m_runnableTasks) {
        connectTask(i);
        tsks.push_back(i);
    }
    coll->setTasks(tsks);
    d->ensureWizardCreated();
    d->m_wizard->addTaskCollection(coll);

    d->ensureWizardVisible();
    QTimer::singleShot(0, this, SLOT(schedule()));
}

void DecryptVerifyEMailController::setInput(const shared_ptr<Input> &input)
{
    d->m_inputs.resize(1, input);
}

void DecryptVerifyEMailController::setInputs(const std::vector<shared_ptr<Input> > &inputs)
{
    d->m_inputs = inputs;
}

void DecryptVerifyEMailController::setSignedData(const shared_ptr<Input> &data)
{
    d->m_signedDatas.resize(1, data);
}

void DecryptVerifyEMailController::setSignedData(const std::vector<shared_ptr<Input> > &data)
{
    d->m_signedDatas = data;
}

void DecryptVerifyEMailController::setOutput(const shared_ptr<Output> &output)
{
    d->m_outputs.resize(1, output);
}

void DecryptVerifyEMailController::setOutputs(const std::vector<shared_ptr<Output> > &outputs)
{
    d->m_outputs = outputs;
}

void DecryptVerifyEMailController::setInformativeSenders(const std::vector<KMime::Types::Mailbox> &senders)
{
    d->m_informativeSenders = senders;
}

void DecryptVerifyEMailController::setWizardShown(bool shown)
{
    d->m_silent = !shown;
    if (d->m_wizard) {
        d->m_wizard->setVisible(shown);
    }
}

void DecryptVerifyEMailController::setOperation(DecryptVerifyOperation operation)
{
    d->m_operation = operation;
}

void DecryptVerifyEMailController::setVerificationMode(VerificationMode vm)
{
    d->m_verificationMode = vm;
}

void DecryptVerifyEMailController::setProtocol(Protocol prot)
{
    d->m_protocol = prot;
}

void DecryptVerifyEMailController::setSessionId(unsigned int id)
{
    qCDebug(KLEOPATRA_LOG) << "id = " << id;
    d->m_sessionId = id;
}

void DecryptVerifyEMailController::cancel()
{
    qCDebug(KLEOPATRA_LOG);
    try {
        if (d->m_wizard) {
            disconnect(d->m_wizard);
            d->m_wizard->close();
        }
        d->cancelAllTasks();
    } catch (const std::exception &e) {
        qCDebug(KLEOPATRA_LOG) << "Caught exception: " << e.what();
    }
}

void DecryptVerifyEMailController::Private::cancelAllTasks()
{

    // we just kill all runnable tasks - this will not result in
    // signal emissions.
    m_runnableTasks.clear();

    // a cancel() will result in a call to
    if (m_runningTask) {
        m_runningTask->cancel();
    }
}

#include "decryptverifyemailcontroller.moc"
#include "moc_decryptverifyemailcontroller.cpp"
