/***************************************************************************
 *   Copyright (C) 2018 by Chinmoy Ranjan Pradhan <chinmoyrp65@gmail.com>  *
 *                                                                         *
 *   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 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include "signaturepropertiesdialog.h"

#include <KColumnResizer>
#include <KLocalizedString>

#include <QDialogButtonBox>
#include <QFormLayout>
#include <QGroupBox>
#include <QLabel>
#include <QPushButton>
#include <QVBoxLayout>
#include <QVector>

#include "core/document.h"
#include "core/form.h"

#include "certificateviewer.h"
#include "revisionviewer.h"
#include "signatureguiutils.h"

static QString getValidDisplayString(const QString &str)
{
    return !str.isEmpty() ? str : i18n("Not Available");
}

SignaturePropertiesDialog::SignaturePropertiesDialog(Okular::Document *doc, const Okular::FormFieldSignature *form, QWidget *parent)
    : QDialog(parent)
    , m_doc(doc)
    , m_signatureForm(form)
{
    setModal(true);
    setWindowTitle(i18n("Signature Properties"));

    const Okular::SignatureInfo &signatureInfo = form->signatureInfo();
    const Okular::SignatureInfo::SignatureStatus signatureStatus = signatureInfo.signatureStatus();
    const QString readableSignatureStatus = SignatureGuiUtils::getReadableSignatureStatus(signatureStatus);
    const QString signerName = getValidDisplayString(signatureInfo.signerName());
    const QString signingTime = getValidDisplayString(signatureInfo.signingTime().toString(Qt::DefaultLocaleLongDate));
    const QString signingLocation = getValidDisplayString(signatureInfo.location());
    const QString signingReason = getValidDisplayString(signatureInfo.reason());

    // signature validation status
    QString modificationSummary;
    if (signatureStatus == Okular::SignatureInfo::SignatureValid) {
        if (signatureInfo.signsTotalDocument()) {
            modificationSummary = i18n("The document has not been modified since it was signed.");
        } else {
            modificationSummary = i18n(
                "The revision of the document that was covered by this signature has not been modified;\n"
                "however there have been subsequent changes to the document.");
        }
    } else if (signatureStatus == Okular::SignatureInfo::SignatureDigestMismatch) {
        modificationSummary = i18n("The document has been modified in a way not permitted by a previous signer.");
    } else {
        modificationSummary = i18n("The document integrity verification could not be completed.");
    }

    auto signatureStatusBox = new QGroupBox(i18n("Validity Status"));
    auto signatureStatusFormLayout = new QFormLayout(signatureStatusBox);
    signatureStatusFormLayout->setLabelAlignment(Qt::AlignLeft);
    signatureStatusFormLayout->addRow(i18n("Signature Validity:"), new QLabel(readableSignatureStatus));
    signatureStatusFormLayout->addRow(i18n("Document Modifications:"), new QLabel(modificationSummary));

    // additional information
    auto extraInfoBox = new QGroupBox(i18n("Additional Information"));
    auto extraInfoFormLayout = new QFormLayout(extraInfoBox);
    extraInfoFormLayout->setLabelAlignment(Qt::AlignLeft);
    extraInfoFormLayout->addRow(i18n("Signed By:"), new QLabel(signerName));
    extraInfoFormLayout->addRow(i18n("Signing Time:"), new QLabel(signingTime));
    extraInfoFormLayout->addRow(i18n("Reason:"), new QLabel(signingReason));
    extraInfoFormLayout->addRow(i18n("Location:"), new QLabel(signingLocation));

    // keep width of column 1 same
    auto resizer = new KColumnResizer(this);
    resizer->addWidgetsFromLayout(signatureStatusFormLayout->layout(), 0);
    resizer->addWidgetsFromLayout(extraInfoFormLayout->layout(), 0);

    // document revision info
    QGroupBox *revisionBox = nullptr;
    if (signatureStatus != Okular::SignatureInfo::SignatureStatusUnknown && !signatureInfo.signsTotalDocument()) {
        revisionBox = new QGroupBox(i18n("Document Version"));
        auto revisionLayout = new QHBoxLayout(revisionBox);
        const QVector<const Okular::FormFieldSignature *> signatureFormFields = SignatureGuiUtils::getSignatureFormFields(m_doc, true, -1);
        revisionLayout->addWidget(new QLabel(i18nc("Document Revision <current> of <total>", "Document Revision %1 of %2", signatureFormFields.indexOf(m_signatureForm) + 1, signatureFormFields.size())));
        revisionLayout->addStretch();
        auto revisionBtn = new QPushButton(i18n("View Signed Version..."));
        connect(revisionBtn, &QPushButton::clicked, this, &SignaturePropertiesDialog::viewSignedVersion);
        revisionLayout->addWidget(revisionBtn);
    }

    // button box
    auto btnBox = new QDialogButtonBox(QDialogButtonBox::Close, this);
    auto certPropBtn = new QPushButton(i18n("View Certificate..."));
    certPropBtn->setEnabled(!signatureInfo.certificateInfo().isNull());
    btnBox->addButton(certPropBtn, QDialogButtonBox::ActionRole);
    connect(btnBox, &QDialogButtonBox::rejected, this, &SignaturePropertiesDialog::reject);
    connect(certPropBtn, &QPushButton::clicked, this, &SignaturePropertiesDialog::viewCertificateProperties);

    auto mainLayout = new QVBoxLayout(this);
    mainLayout->addWidget(signatureStatusBox);
    mainLayout->addWidget(extraInfoBox);
    if (revisionBox) {
        mainLayout->addWidget(revisionBox);
    }
    mainLayout->addWidget(btnBox);

    resize(mainLayout->sizeHint());
}

void SignaturePropertiesDialog::viewCertificateProperties()
{
    CertificateViewer certViewer(m_signatureForm->signatureInfo().certificateInfo(), this);
    certViewer.exec();
}

void SignaturePropertiesDialog::viewSignedVersion()
{
    const QByteArray data = m_doc->requestSignedRevisionData(m_signatureForm->signatureInfo());
    RevisionViewer revViewer(data, this);
    revViewer.viewRevision();
}

#include "moc_signaturepropertiesdialog.cpp"
