/* -*- mode: c++; c-basic-offset:4 -*-
    decryptverifyfilescontroller.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 "decryptverifyfilescontroller.h"

#include <crypto/gui/decryptverifyoperationwidget.h>
#include <crypto/gui/decryptverifyfileswizard.h>
#include <crypto/decryptverifytask.h>
#include <crypto/taskcollection.h>

#include <utils/gnupg-helper.h>
#include <utils/path-helper.h>
#include <utils/input.h>
#include <utils/output.h>
#include <utils/kleo_assert.h>
#include <utils/archivedefinition.h>

#include <Libkleo/Classify>

#include <KLocalizedString>
#include "kleopatra_debug.h"

#include <QDir>
#include <QFile>
#include <QFileInfo>
#include <QPointer>
#include <QTimer>

#include <memory>
#include <vector>

using namespace GpgME;
using namespace Kleo;
using namespace Kleo::Crypto;
using namespace Kleo::Crypto::Gui;

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

    static std::shared_ptr<AbstractDecryptVerifyTask> taskFromOperationWidget(const DecryptVerifyOperationWidget *w, const QString &fileName, const QDir &outDir, const std::shared_ptr<OverwritePolicy> &overwritePolicy);

    explicit Private(DecryptVerifyFilesController *qq);

    void slotWizardOperationPrepared();
    void slotWizardCanceled();
    void schedule();

    void prepareWizardFromPassedFiles();
    std::vector<std::shared_ptr<Task> > buildTasks(const QStringList &, const std::shared_ptr<OverwritePolicy> &);

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

    QStringList m_passedFiles, m_filesAfterPreparation;
    QPointer<DecryptVerifyFilesWizard> m_wizard;
    std::vector<std::shared_ptr<const DecryptVerifyResult> > m_results;
    std::vector<std::shared_ptr<Task> > m_runnableTasks, m_completedTasks;
    std::shared_ptr<Task> m_runningTask;
    bool m_errorDetected;
    DecryptVerifyOperation m_operation;
};

// static
std::shared_ptr<AbstractDecryptVerifyTask> DecryptVerifyFilesController::Private::taskFromOperationWidget(const DecryptVerifyOperationWidget *w, const QString &fileName, const QDir &outDir, const std::shared_ptr<OverwritePolicy> &overwritePolicy)
{

    kleo_assert(w);

    std::shared_ptr<AbstractDecryptVerifyTask> task;

    switch (w->mode()) {
    case DecryptVerifyOperationWidget::VerifyDetachedWithSignature: {

        std::shared_ptr<VerifyDetachedTask> t(new VerifyDetachedTask);
        t->setInput(Input::createFromFile(fileName));
        t->setSignedData(Input::createFromFile(w->signedDataFileName()));
        task = t;

        kleo_assert(fileName == w->inputFileName());
    }
    break;
    case DecryptVerifyOperationWidget::VerifyDetachedWithSignedData: {
        std::shared_ptr<VerifyDetachedTask> t(new VerifyDetachedTask);
        t->setInput(Input::createFromFile(w->inputFileName()));
        t->setSignedData(Input::createFromFile(fileName));
        task = t;

        kleo_assert(fileName == w->signedDataFileName());
    }
    break;
    case DecryptVerifyOperationWidget::DecryptVerifyOpaque: {
        const unsigned int classification = classify(fileName);
        qCDebug(KLEOPATRA_LOG) << "classified" << fileName << "as" << printableClassification(classification);

        const std::shared_ptr<ArchiveDefinition> ad = w->selectedArchiveDefinition();

        const Protocol proto =
            isOpenPGP(classification) ? OpenPGP :
            isCMS(classification)     ? CMS :
            ad /* _needs_ the info */   ? throw Exception(gpg_error(GPG_ERR_CONFLICT), i18n("Cannot determine whether input data is OpenPGP or CMS")) :
            /* else we don't care */      UnknownProtocol;

        const std::shared_ptr<Input> input = Input::createFromFile(fileName);
        const std::shared_ptr<Output> output =
            ad       ? ad->createOutputFromUnpackCommand(proto, fileName, outDir) :
            /*else*/   Output::createFromFile(outDir.absoluteFilePath(outputFileName(QFileInfo(fileName).fileName())), overwritePolicy);

        if (mayBeCipherText(classification)) {
            qCDebug(KLEOPATRA_LOG) << "creating a DecryptVerifyTask";
            std::shared_ptr<DecryptVerifyTask> t(new DecryptVerifyTask);
            t->setInput(input);
            t->setOutput(output);
            task = t;
        } else {
            qCDebug(KLEOPATRA_LOG) << "creating a VerifyOpaqueTask";
            std::shared_ptr<VerifyOpaqueTask> t(new VerifyOpaqueTask);
            t->setInput(input);
            t->setOutput(output);
            task = t;
        }

        kleo_assert(fileName == w->inputFileName());
    }
    break;
    }

    task->autodetectProtocolFromInput();
    return task;
}

DecryptVerifyFilesController::Private::Private(DecryptVerifyFilesController *qq) : q(qq), m_errorDetected(false), m_operation(DecryptVerify)
{
    qRegisterMetaType<VerificationResult>();
}

void DecryptVerifyFilesController::Private::slotWizardOperationPrepared()
{
    ensureWizardCreated();
    std::vector<std::shared_ptr<Task> > tasks = buildTasks(m_filesAfterPreparation, std::shared_ptr<OverwritePolicy>(new OverwritePolicy(m_wizard)));
    if (tasks.empty()) {
        reportError(makeGnuPGError(GPG_ERR_ASS_NO_INPUT), i18n("No usable inputs found"));
    }
    kleo_assert(m_runnableTasks.empty());
    m_runnableTasks.swap(tasks);

    std::shared_ptr<TaskCollection> coll(new TaskCollection);
    for (const auto &i: m_runnableTasks) {
        q->connectTask(i);
    }
    coll->setTasks(m_runnableTasks);
    m_wizard->setTaskCollection(coll);

    QTimer::singleShot(0, q, SLOT(schedule()));
}

void DecryptVerifyFilesController::Private::slotWizardCanceled()
{
    qCDebug(KLEOPATRA_LOG);
}

void DecryptVerifyFilesController::doTaskDone(const Task *task, const std::shared_ptr<const Task::Result> &result)
{
    Q_ASSERT(task);
    Q_UNUSED(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

    d->m_completedTasks.push_back(d->m_runningTask);
    d->m_runningTask.reset();

    if (const std::shared_ptr<const DecryptVerifyResult> &dvr = std::dynamic_pointer_cast<const DecryptVerifyResult>(result)) {
        d->m_results.push_back(dvr);
    }

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

void DecryptVerifyFilesController::Private::schedule()
{
    if (!m_runningTask && !m_runnableTasks.empty()) {
        const std::shared_ptr<Task> t = m_runnableTasks.back();
        m_runnableTasks.pop_back();
        t->start();
        m_runningTask = t;
    }
    if (!m_runningTask) {
        kleo_assert(m_runnableTasks.empty());
        for (const auto &i: m_results) {
            Q_EMIT q->verificationResult(i->verificationResult());
        }
        q->emitDoneOrError();
    }
}

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

    std::unique_ptr<DecryptVerifyFilesWizard> w(new DecryptVerifyFilesWizard);
    w->setWindowTitle(i18nc("@title:window", "Decrypt/Verify Files"));
    w->setAttribute(Qt::WA_DeleteOnClose);

    connect(w.get(), SIGNAL(operationPrepared()), q, SLOT(slotWizardOperationPrepared()), Qt::QueuedConnection);
    connect(w.get(), SIGNAL(canceled()), q, SLOT(slotWizardCanceled()), Qt::QueuedConnection);
    m_wizard = w.release();

}

namespace
{
struct FindExtension : std::unary_function<std::shared_ptr<ArchiveDefinition>, bool> {
    const QString ext;
    const Protocol proto;
    FindExtension(const QString &ext, Protocol proto) : ext(ext), proto(proto) {}
    bool operator()(const std::shared_ptr<ArchiveDefinition> &ad) const
    {
        qCDebug(KLEOPATRA_LOG) << "   considering" << (ad ? ad->label() : QStringLiteral("<null>")) << "for" << ext;
        bool result;
        if (proto == UnknownProtocol) {
            result = ad && (ad->extensions(OpenPGP).contains(ext, Qt::CaseInsensitive) || ad->extensions(CMS).contains(ext, Qt::CaseInsensitive));
        } else {
            result = ad && ad->extensions(proto).contains(ext, Qt::CaseInsensitive);
        }
        qCDebug(KLEOPATRA_LOG) << (result ? "   -> matches" : "   -> doesn't match");
        return result;
    }
};
}

std::shared_ptr<ArchiveDefinition> DecryptVerifyFilesController::pick_archive_definition(GpgME::Protocol proto, const std::vector< std::shared_ptr<ArchiveDefinition> > &ads, const QString &filename)
{
    const QFileInfo fi(outputFileName(filename));
    QString extension = fi.completeSuffix();

    if (extension == QLatin1String("out")) { // added by outputFileName() -> useless
        return std::shared_ptr<ArchiveDefinition>();
    }

    if (extension.endsWith(QLatin1String(".out"))) {     // added by outputFileName() -> remove
        extension.chop(4);
    }

    for (;;) {
        const std::vector<std::shared_ptr<ArchiveDefinition> >::const_iterator it
            = std::find_if(ads.begin(), ads.end(), FindExtension(extension, proto));
        if (it != ads.end()) {
            return *it;
        }
        const int idx = extension.indexOf(QLatin1Char('.'));
        if (idx < 0) {
            return std::shared_ptr<ArchiveDefinition>();
        }
        extension = extension.mid(idx + 1);
    }
}

void DecryptVerifyFilesController::Private::prepareWizardFromPassedFiles()
{
    ensureWizardCreated();
    const std::vector< std::shared_ptr<ArchiveDefinition> > archiveDefinitions = ArchiveDefinition::getArchiveDefinitions();

    unsigned int counter = 0;
    for (const auto &fname: qAsConst(m_passedFiles)) {
        kleo_assert(!fname.isEmpty());

        const unsigned int classification = classify(fname);
        const Protocol proto = findProtocol(classification);

        if (mayBeOpaqueSignature(classification) || mayBeCipherText(classification) || mayBeDetachedSignature(classification)) {

            DecryptVerifyOperationWidget *const op = m_wizard->operationWidget(counter++);
            kleo_assert(op != nullptr);

            op->setArchiveDefinitions(archiveDefinitions);

            const QString signedDataFileName = findSignedData(fname);

            // this breaks opaque signatures whose source files still
            // happen to exist in the same directory. Until we have
            // content-based classification, this is the most unlikely
            // case, so that's the case we break. ### FIXME remove when content-classify is done
            if (mayBeDetachedSignature(classification) && !signedDataFileName.isEmpty()) {
                op->setMode(DecryptVerifyOperationWidget::VerifyDetachedWithSignature);
            }
            // ### end FIXME
            else if (mayBeOpaqueSignature(classification) || mayBeCipherText(classification)) {
                op->setMode(DecryptVerifyOperationWidget::DecryptVerifyOpaque, q->pick_archive_definition(proto, archiveDefinitions, fname));
            } else {
                op->setMode(DecryptVerifyOperationWidget::VerifyDetachedWithSignature);
            }

            op->setInputFileName(fname);
            op->setSignedDataFileName(signedDataFileName);

            m_filesAfterPreparation << fname;

        } else {

            // probably the signed data file was selected:
            const QStringList signatures = findSignatures(fname);

            if (signatures.empty()) {
                // We are assuming this is a detached signature file, but
                // there were no signature files for it. Let's guess it's encrypted after all.
                // ### FIXME once we have a proper heuristic for this, this should move into
                // classify() and/or classifyContent()
                DecryptVerifyOperationWidget *const op = m_wizard->operationWidget(counter++);
                kleo_assert(op != nullptr);
                op->setArchiveDefinitions(archiveDefinitions);
                op->setMode(DecryptVerifyOperationWidget::DecryptVerifyOpaque, q->pick_archive_definition(proto, archiveDefinitions, fname));
                op->setInputFileName(fname);
                m_filesAfterPreparation << fname;
            } else {
                for (const auto &s: signatures) {
                    DecryptVerifyOperationWidget *op = m_wizard->operationWidget(counter++);
                    kleo_assert(op != nullptr);

                    op->setArchiveDefinitions(archiveDefinitions);
                    op->setMode(DecryptVerifyOperationWidget::VerifyDetachedWithSignedData);
                    op->setInputFileName(s);
                    op->setSignedDataFileName(fname);

                    m_filesAfterPreparation << fname;
                }

            }
        }
    }

    m_wizard->setOutputDirectory(heuristicBaseDirectory(m_passedFiles));
    return;
}

std::vector< std::shared_ptr<Task> > DecryptVerifyFilesController::Private::buildTasks(const QStringList &fileNames, const std::shared_ptr<OverwritePolicy> &overwritePolicy)
{
    const bool useOutDir = m_wizard->useOutputDirectory();
    const QFileInfo outDirInfo(m_wizard->outputDirectory());

    kleo_assert(!useOutDir || outDirInfo.isDir());

    const QDir outDir(outDirInfo.absoluteFilePath());
    kleo_assert(!useOutDir || outDir.exists());

    std::vector<std::shared_ptr<Task> > tasks;
    for (int i = 0, end  = fileNames.size(); i != end; ++i)
        try {
            const QDir fileDir = QFileInfo(fileNames[i]).absoluteDir();
            kleo_assert(fileDir.exists());
            tasks.push_back(taskFromOperationWidget(m_wizard->operationWidget(static_cast<unsigned int>(i)), fileNames[i], useOutDir ? outDir : fileDir, overwritePolicy));
        } catch (const GpgME::Exception &e) {
            tasks.push_back(Task::makeErrorTask(e.error().code(), QString::fromLocal8Bit(e.what()), fileNames[i]));
        }

    return tasks;
}

void DecryptVerifyFilesController::setFiles(const QStringList &files)
{
    d->m_passedFiles = files;
}

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

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

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

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

void DecryptVerifyFilesController::start()
{
    d->prepareWizardFromPassedFiles();
    d->ensureWizardVisible();
}

void DecryptVerifyFilesController::setOperation(DecryptVerifyOperation op)
{
    d->m_operation = op;
}

DecryptVerifyOperation DecryptVerifyFilesController::operation() const
{
    return d->m_operation;
}

void DecryptVerifyFilesController::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();
    }
}

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

#include "moc_decryptverifyfilescontroller.cpp"
