/*
 *  Copyright (C) 2011 Felix Geyer <debfx@fobos.de>
 *  Copyright (C) 2017 KeePassXC Team <team@keepassxc.org>
 *
 *  This program 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 or (at your option)
 *  version 3 of the License.
 *
 *  This program 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, see <http://www.gnu.org/licenses/>.
 */

#include "DatabaseOpenWidget.h"
#include "ui_DatabaseOpenWidget.h"

#include "config-keepassx.h"
#include "gui/FileDialog.h"
#include "gui/Icons.h"
#include "gui/MainWindow.h"
#include "gui/MessageBox.h"
#include "keys/ChallengeResponseKey.h"
#include "keys/FileKey.h"

#ifdef Q_OS_MACOS
#include "touchid/TouchID.h"
#endif

#include <QDesktopServices>
#include <QFont>

namespace
{
    constexpr int clearFormsDelay = 30000;
}

DatabaseOpenWidget::DatabaseOpenWidget(QWidget* parent)
    : DialogyWidget(parent)
    , m_ui(new Ui::DatabaseOpenWidget())
    , m_db(nullptr)
{
    m_ui->setupUi(this);

    m_ui->messageWidget->setHidden(true);

    m_hideTimer.setInterval(clearFormsDelay);
    m_hideTimer.setSingleShot(true);
    connect(&m_hideTimer, &QTimer::timeout, this, [this] {
        // Reset the password field after being hidden for a set time
        m_ui->editPassword->setText("");
        m_ui->editPassword->setShowPassword(false);
    });

    QFont font;
    font.setPointSize(font.pointSize() + 4);
    font.setBold(true);
    m_ui->labelHeadline->setFont(font);
    m_ui->labelHeadline->setText(tr("Unlock KeePassXC Database"));

    connect(m_ui->buttonBrowseFile, SIGNAL(clicked()), SLOT(browseKeyFile()));

    connect(m_ui->buttonBox, SIGNAL(accepted()), SLOT(openDatabase()));
    connect(m_ui->buttonBox, SIGNAL(rejected()), SLOT(reject()));

    m_ui->hardwareKeyLabelHelp->setIcon(icons()->icon("system-help").pixmap(QSize(12, 12)));
    connect(m_ui->hardwareKeyLabelHelp, SIGNAL(clicked(bool)), SLOT(openHardwareKeyHelp()));
    m_ui->keyFileLabelHelp->setIcon(icons()->icon("system-help").pixmap(QSize(12, 12)));
    connect(m_ui->keyFileLabelHelp, SIGNAL(clicked(bool)), SLOT(openKeyFileHelp()));

#ifdef WITH_XC_YUBIKEY
    m_ui->hardwareKeyProgress->setVisible(false);
    QSizePolicy sp = m_ui->hardwareKeyProgress->sizePolicy();
    sp.setRetainSizeWhenHidden(true);
    m_ui->hardwareKeyProgress->setSizePolicy(sp);

    connect(m_ui->buttonRedetectYubikey, SIGNAL(clicked()), SLOT(pollHardwareKey()));
    connect(YubiKey::instance(), SIGNAL(detectComplete(bool)), SLOT(hardwareKeyResponse(bool)), Qt::QueuedConnection);

    connect(YubiKey::instance(), &YubiKey::userInteractionRequest, this, [this] {
        // Show the press notification if we are in an independent window (e.g., DatabaseOpenDialog)
        if (window() != getMainWindow()) {
            m_ui->messageWidget->showMessage(tr("Please present or touch your YubiKey to continue…"),
                                             MessageWidget::Information,
                                             MessageWidget::DisableAutoHide);
        }
    });
    connect(YubiKey::instance(), &YubiKey::challengeCompleted, this, [this] { m_ui->messageWidget->hide(); });
#else
    m_ui->hardwareKeyLabel->setVisible(false);
    m_ui->hardwareKeyLabelHelp->setVisible(false);
    m_ui->buttonRedetectYubikey->setVisible(false);
    m_ui->challengeResponseCombo->setVisible(false);
    m_ui->hardwareKeyProgress->setVisible(false);
#endif

#ifndef WITH_XC_TOUCHID
    m_ui->touchIDContainer->setVisible(false);
#else
    if (!TouchID::getInstance().isAvailable()) {
        m_ui->checkTouchID->setVisible(false);
    }
#endif
}

DatabaseOpenWidget::~DatabaseOpenWidget()
{
}

void DatabaseOpenWidget::showEvent(QShowEvent* event)
{
    DialogyWidget::showEvent(event);
    m_ui->editPassword->setFocus();
    m_hideTimer.stop();
}

void DatabaseOpenWidget::hideEvent(QHideEvent* event)
{
    DialogyWidget::hideEvent(event);

    // Schedule form clearing if we are hidden
    if (!isVisible()) {
        m_hideTimer.start();
    }
}

void DatabaseOpenWidget::load(const QString& filename)
{
    clearForms();

    m_filename = filename;
    m_ui->fileNameLabel->setRawText(m_filename);

    if (config()->get(Config::RememberLastKeyFiles).toBool()) {
        auto lastKeyFiles = config()->get(Config::LastKeyFiles).toHash();
        if (lastKeyFiles.contains(m_filename)) {
            m_ui->keyFileLineEdit->setText(lastKeyFiles[m_filename].toString());
        }
    }

    QHash<QString, QVariant> useTouchID = config()->get(Config::UseTouchID).toHash();
    m_ui->checkTouchID->setChecked(useTouchID.value(m_filename, false).toBool());

#ifdef WITH_XC_YUBIKEY
    // Only auto-poll for hardware keys if we previously used one with this database file
    if (config()->get(Config::RememberLastKeyFiles).toBool()) {
        auto lastChallengeResponse = config()->get(Config::LastChallengeResponse).toHash();
        if (lastChallengeResponse.contains(m_filename)) {
            pollHardwareKey();
        }
    }
#endif
}

void DatabaseOpenWidget::clearForms()
{
    m_ui->editPassword->setText("");
    m_ui->editPassword->setShowPassword(false);
    m_ui->keyFileLineEdit->clear();
    m_ui->keyFileLineEdit->setShowPassword(false);
    m_ui->checkTouchID->setChecked(false);
    m_ui->challengeResponseCombo->clear();
    m_db.reset();
}

QSharedPointer<Database> DatabaseOpenWidget::database()
{
    return m_db;
}

QString DatabaseOpenWidget::filename()
{
    return m_filename;
}

void DatabaseOpenWidget::enterKey(const QString& pw, const QString& keyFile)
{
    m_ui->editPassword->setText(pw);
    m_ui->keyFileLineEdit->setText(keyFile);
    openDatabase();
}

void DatabaseOpenWidget::openDatabase()
{
    m_ui->messageWidget->hide();

    QSharedPointer<CompositeKey> databaseKey = buildDatabaseKey();
    if (!databaseKey) {
        return;
    }

    m_ui->editPassword->setShowPassword(false);
    QCoreApplication::processEvents();

    m_db.reset(new Database());
    QString error;

    QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
    m_ui->passwordFormFrame->setEnabled(false);
    QCoreApplication::processEvents();
    bool ok = m_db->open(m_filename, databaseKey, &error, false);
    QApplication::restoreOverrideCursor();
    m_ui->passwordFormFrame->setEnabled(true);

    if (ok && m_db->hasMinorVersionMismatch()) {
        QScopedPointer<QMessageBox> msgBox(new QMessageBox(this));
        msgBox->setIcon(QMessageBox::Warning);
        msgBox->setWindowTitle(tr("Database Version Mismatch"));
        msgBox->setText(tr("The database you are trying to open was most likely\n"
                           "created by a newer version of KeePassXC.\n\n"
                           "You can try to open it anyway, but it may be incomplete\n"
                           "and saving any changes may incur data loss.\n\n"
                           "We recommend you update your KeePassXC installation."));
        auto btn = msgBox->addButton(tr("Open database anyway"), QMessageBox::ButtonRole::AcceptRole);
        msgBox->setDefaultButton(btn);
        msgBox->addButton(QMessageBox::Cancel);
        msgBox->exec();
        if (msgBox->clickedButton() != btn) {
            m_db.reset(new Database());
            m_ui->messageWidget->showMessage(tr("Database unlock canceled."), MessageWidget::MessageType::Error);
            return;
        }
    }

    if (ok) {
#ifdef WITH_XC_TOUCHID
        QHash<QString, QVariant> useTouchID = config()->get(Config::UseTouchID).toHash();

        // check if TouchID can & should be used to unlock the database next time
        if (m_ui->checkTouchID->isChecked() && TouchID::getInstance().isAvailable()) {
            // encrypt and store key blob
            if (TouchID::getInstance().storeKey(m_filename, PasswordKey(m_ui->editPassword->text()).rawKey())) {
                useTouchID.insert(m_filename, true);
            }
        } else {
            // when TouchID not available or unchecked, reset for the current database
            TouchID::getInstance().reset(m_filename);
            useTouchID.insert(m_filename, false);
        }

        config()->set(Config::UseTouchID, useTouchID);
#endif
        emit dialogFinished(true);
        clearForms();
    } else {
        if (m_ui->editPassword->text().isEmpty() && !m_retryUnlockWithEmptyPassword) {
            QScopedPointer<QMessageBox> msgBox(new QMessageBox(this));
            msgBox->setIcon(QMessageBox::Critical);
            msgBox->setWindowTitle(tr("Unlock failed and no password given"));
            msgBox->setText(tr("Unlocking the database failed and you did not enter a password.\n"
                               "Do you want to retry with an \"empty\" password instead?\n\n"
                               "To prevent this error from appearing, you must go to "
                               "\"Database Settings / Security\" and reset your password."));
            auto btn = msgBox->addButton(tr("Retry with empty password"), QMessageBox::ButtonRole::AcceptRole);
            msgBox->setDefaultButton(btn);
            msgBox->addButton(QMessageBox::Cancel);
            msgBox->exec();

            if (msgBox->clickedButton() == btn) {
                m_retryUnlockWithEmptyPassword = true;
                openDatabase();
                return;
            }
        }

        m_retryUnlockWithEmptyPassword = false;
        m_ui->messageWidget->showMessage(error, MessageWidget::MessageType::Error);
        // Focus on the password field and select the input for easy retry
        m_ui->editPassword->selectAll();
        m_ui->editPassword->setFocus();

#ifdef WITH_XC_TOUCHID
        // unable to unlock database, reset TouchID for the current database
        TouchID::getInstance().reset(m_filename);
#endif
    }
}

QSharedPointer<CompositeKey> DatabaseOpenWidget::buildDatabaseKey()
{
    auto databaseKey = QSharedPointer<CompositeKey>::create();

    if (!m_ui->editPassword->text().isEmpty() || m_retryUnlockWithEmptyPassword) {
        databaseKey->addKey(QSharedPointer<PasswordKey>::create(m_ui->editPassword->text()));
    }

#ifdef WITH_XC_TOUCHID
    // check if TouchID is available and enabled for unlocking the database
    if (m_ui->checkTouchID->isChecked() && TouchID::getInstance().isAvailable()
        && m_ui->editPassword->text().isEmpty()) {
        // clear empty password from composite key
        databaseKey->clear();

        // try to get, decrypt and use PasswordKey
        QByteArray passwordKey;
        if (TouchID::getInstance().getKey(m_filename, passwordKey)) {
            // check if the user cancelled the operation
            if (passwordKey.isNull()) {
                return QSharedPointer<CompositeKey>();
            }

            databaseKey->addKey(PasswordKey::fromRawKey(passwordKey));
        }
    }
#endif

    auto lastKeyFiles = config()->get(Config::LastKeyFiles).toHash();
    lastKeyFiles.remove(m_filename);

    auto key = QSharedPointer<FileKey>::create();
    QString keyFilename = m_ui->keyFileLineEdit->text();
    if (!keyFilename.isEmpty()) {
        QString errorMsg;
        if (!key->load(keyFilename, &errorMsg)) {
            m_ui->messageWidget->showMessage(tr("Failed to open key file: %1").arg(errorMsg), MessageWidget::Error);
            return {};
        }
        if (key->type() != FileKey::KeePass2XMLv2 && key->type() != FileKey::Hashed
            && !config()->get(Config::Messages_NoLegacyKeyFileWarning).toBool()) {
            QMessageBox legacyWarning;
            legacyWarning.setWindowTitle(tr("Old key file format"));
            legacyWarning.setText(tr("You are using an old key file format which KeePassXC may<br>"
                                     "stop supporting in the future.<br><br>"
                                     "Please consider generating a new key file by going to:<br>"
                                     "<strong>Database &gt; Database Security &gt; Change Key File.</strong><br>"));
            legacyWarning.setIcon(QMessageBox::Icon::Warning);
            legacyWarning.addButton(QMessageBox::Ok);
            legacyWarning.setDefaultButton(QMessageBox::Ok);
            legacyWarning.setCheckBox(new QCheckBox(tr("Don't show this warning again")));

            connect(legacyWarning.checkBox(), &QCheckBox::stateChanged, this, [](int state) {
                config()->set(Config::Messages_NoLegacyKeyFileWarning, state == Qt::CheckState::Checked);
            });

            legacyWarning.exec();
        }
        databaseKey->addKey(key);
        lastKeyFiles.insert(m_filename, keyFilename);
    }

    if (config()->get(Config::RememberLastKeyFiles).toBool()) {
        config()->set(Config::LastKeyFiles, lastKeyFiles);
    }

#ifdef WITH_XC_YUBIKEY
    auto lastChallengeResponse = config()->get(Config::LastChallengeResponse).toHash();
    lastChallengeResponse.remove(m_filename);

    int selectionIndex = m_ui->challengeResponseCombo->currentIndex();
    if (selectionIndex > 0) {
        auto slot = m_ui->challengeResponseCombo->itemData(selectionIndex).value<YubiKeySlot>();
        auto crKey = QSharedPointer<ChallengeResponseKey>(new ChallengeResponseKey(slot));
        databaseKey->addChallengeResponseKey(crKey);

        // Qt doesn't read custom types in settings so stuff into a QString
        lastChallengeResponse.insert(m_filename, QStringLiteral("%1:%2").arg(slot.first).arg(slot.second));
    }

    if (config()->get(Config::RememberLastKeyFiles).toBool()) {
        config()->set(Config::LastChallengeResponse, lastChallengeResponse);
    }
#endif

    return databaseKey;
}

void DatabaseOpenWidget::reject()
{
    emit dialogFinished(false);
}

void DatabaseOpenWidget::browseKeyFile()
{
    QString filters = QString("%1 (*);;%2 (*.keyx; *.key)").arg(tr("All files"), tr("Key files"));
    QString filename = fileDialog()->getOpenFileName(this, tr("Select key file"), QString(), filters);

    if (QFileInfo(filename).canonicalFilePath() == QFileInfo(m_filename).canonicalFilePath()) {
        MessageBox::warning(this,
                            tr("Cannot use database file as key file"),
                            tr("You cannot use your database file as a key file.\nIf you do not have a key file, "
                               "please leave the field empty."),
                            MessageBox::Button::Ok);
        filename = "";
    }

    if (!filename.isEmpty()) {
        m_ui->keyFileLineEdit->setText(filename);
    }
}

void DatabaseOpenWidget::clearKeyFileText()
{
    m_ui->keyFileLineEdit->clear();
    m_ui->keyFileLineEdit->setShowPassword(false);
}

void DatabaseOpenWidget::pollHardwareKey()
{
    if (m_pollingHardwareKey) {
        return;
    }

    m_ui->challengeResponseCombo->clear();
    m_ui->challengeResponseCombo->addItem(tr("Detecting hardware keys…"));

    m_ui->buttonRedetectYubikey->setEnabled(false);
    m_ui->challengeResponseCombo->setEnabled(false);
    m_ui->hardwareKeyProgress->setVisible(true);
    m_pollingHardwareKey = true;

    YubiKey::instance()->findValidKeys();
}

void DatabaseOpenWidget::hardwareKeyResponse(bool found)
{
    m_ui->challengeResponseCombo->clear();
    m_ui->buttonRedetectYubikey->setEnabled(true);
    m_ui->hardwareKeyProgress->setVisible(false);
    m_pollingHardwareKey = false;

    if (!found) {
        m_ui->challengeResponseCombo->addItem(tr("No hardware keys detected"));
        m_ui->challengeResponseCombo->setEnabled(false);
        return;
    } else {
        m_ui->challengeResponseCombo->addItem(tr("Select hardware key…"));
    }

    YubiKeySlot lastUsedSlot;
    if (config()->get(Config::RememberLastKeyFiles).toBool()) {
        auto lastChallengeResponse = config()->get(Config::LastChallengeResponse).toHash();
        if (lastChallengeResponse.contains(m_filename)) {
            // Qt doesn't read custom types in settings so extract from QString
            auto split = lastChallengeResponse.value(m_filename).toString().split(":");
            if (split.size() > 1) {
                lastUsedSlot = YubiKeySlot(split[0].toUInt(), split[1].toInt());
            }
        }
    }

    int selectedIndex = 0;
    for (auto& slot : YubiKey::instance()->foundKeys()) {
        // add detected YubiKey to combo box
        m_ui->challengeResponseCombo->addItem(YubiKey::instance()->getDisplayName(slot), QVariant::fromValue(slot));
        // Select this YubiKey + Slot if we used it in the past
        if (lastUsedSlot == slot) {
            selectedIndex = m_ui->challengeResponseCombo->count() - 1;
        }
    }

    m_ui->challengeResponseCombo->setCurrentIndex(selectedIndex);
    m_ui->challengeResponseCombo->setEnabled(true);
}

void DatabaseOpenWidget::openHardwareKeyHelp()
{
    QDesktopServices::openUrl(QUrl("https://keepassxc.org/docs#faq-cat-yubikey"));
}

void DatabaseOpenWidget::openKeyFileHelp()
{
    QDesktopServices::openUrl(QUrl("https://keepassxc.org/docs#faq-cat-keyfile"));
}