// SPDX-FileCopyrightText: 2009 Manjeet Dahiya <manjeetdahiya@gmail.com>
// SPDX-FileCopyrightText: 2010 Jeremy Lainé <jeremy.laine@m4x.org>
// SPDX-FileCopyrightText: 2015 Georg Rudoy <0xd34df00d@gmail.com>
// SPDX-FileCopyrightText: 2019 Linus Jahn <lnj@kaidan.im>
// SPDX-FileCopyrightText: 2022 Melvin Keskin <melvo@olomono.de>
//
// SPDX-License-Identifier: LGPL-2.1-or-later

#include "QXmppStanza.h"

#include "QXmppConstants_p.h"
#include "QXmppE2eeMetadata.h"
#include "QXmppStanza_p.h"
#include "QXmppUtils.h"

#include <QDateTime>
#include <QDomElement>
#include <QXmlStreamWriter>

using namespace QXmpp::Private;

uint QXmppStanza::s_uniqeIdNo = 0;

namespace QXmpp::Private {

QString conditionToString(QXmppStanza::Error::Condition condition)
{
    switch (condition) {
    case QXmppStanza::Error::NoCondition:
        return {};
    case QXmppStanza::Error::BadRequest:
        return QStringLiteral("bad-request");
    case QXmppStanza::Error::Conflict:
        return QStringLiteral("conflict");
    case QXmppStanza::Error::FeatureNotImplemented:
        return QStringLiteral("feature-not-implemented");
    case QXmppStanza::Error::Forbidden:
        return QStringLiteral("forbidden");
    case QXmppStanza::Error::Gone:
        return QStringLiteral("gone");
    case QXmppStanza::Error::InternalServerError:
        return QStringLiteral("internal-server-error");
    case QXmppStanza::Error::ItemNotFound:
        return QStringLiteral("item-not-found");
    case QXmppStanza::Error::JidMalformed:
        return QStringLiteral("jid-malformed");
    case QXmppStanza::Error::NotAcceptable:
        return QStringLiteral("not-acceptable");
    case QXmppStanza::Error::NotAllowed:
        return QStringLiteral("not-allowed");
    case QXmppStanza::Error::NotAuthorized:
        return QStringLiteral("not-authorized");
        QT_WARNING_PUSH
        QT_WARNING_DISABLE_DEPRECATED
    case QXmppStanza::Error::PaymentRequired:
        QT_WARNING_POP
        return QStringLiteral("payment-required");
    case QXmppStanza::Error::PolicyViolation:
        return QStringLiteral("policy-violation");
    case QXmppStanza::Error::RecipientUnavailable:
        return QStringLiteral("recipient-unavailable");
    case QXmppStanza::Error::Redirect:
        return QStringLiteral("redirect");
    case QXmppStanza::Error::RegistrationRequired:
        return QStringLiteral("registration-required");
    case QXmppStanza::Error::RemoteServerNotFound:
        return QStringLiteral("remote-server-not-found");
    case QXmppStanza::Error::RemoteServerTimeout:
        return QStringLiteral("remote-server-timeout");
    case QXmppStanza::Error::ResourceConstraint:
        return QStringLiteral("resource-constraint");
    case QXmppStanza::Error::ServiceUnavailable:
        return QStringLiteral("service-unavailable");
    case QXmppStanza::Error::SubscriptionRequired:
        return QStringLiteral("subscription-required");
    case QXmppStanza::Error::UndefinedCondition:
        return QStringLiteral("undefined-condition");
    case QXmppStanza::Error::UnexpectedRequest:
        return QStringLiteral("unexpected-request");
    }
    return {};
}

std::optional<QXmppStanza::Error::Condition> conditionFromString(const QString &string)
{
    if (string == "bad-request") {
        return QXmppStanza::Error::BadRequest;
    } else if (string == "conflict") {
        return QXmppStanza::Error::Conflict;
    } else if (string == "feature-not-implemented") {
        return QXmppStanza::Error::FeatureNotImplemented;
    } else if (string == "forbidden") {
        return QXmppStanza::Error::Forbidden;
    } else if (string == "gone") {
        return QXmppStanza::Error::Gone;
    } else if (string == "internal-server-error") {
        return QXmppStanza::Error::InternalServerError;
    } else if (string == "item-not-found") {
        return QXmppStanza::Error::ItemNotFound;
    } else if (string == "jid-malformed") {
        return QXmppStanza::Error::JidMalformed;
    } else if (string == "not-acceptable") {
        return QXmppStanza::Error::NotAcceptable;
    } else if (string == "not-allowed") {
        return QXmppStanza::Error::NotAllowed;
    } else if (string == "not-authorized") {
        return QXmppStanza::Error::NotAuthorized;
    } else if (string == "payment-required") {
        QT_WARNING_PUSH
        QT_WARNING_DISABLE_DEPRECATED
        return QXmppStanza::Error::PaymentRequired;
        QT_WARNING_POP
    } else if (string == "policy-violation") {
        return QXmppStanza::Error::PolicyViolation;
    } else if (string == "recipient-unavailable") {
        return QXmppStanza::Error::RecipientUnavailable;
    } else if (string == "redirect") {
        return QXmppStanza::Error::Redirect;
    } else if (string == "registration-required") {
        return QXmppStanza::Error::RegistrationRequired;
    } else if (string == "remote-server-not-found") {
        return QXmppStanza::Error::RemoteServerNotFound;
    } else if (string == "remote-server-timeout") {
        return QXmppStanza::Error::RemoteServerTimeout;
    } else if (string == "resource-constraint") {
        return QXmppStanza::Error::ResourceConstraint;
    } else if (string == "service-unavailable") {
        return QXmppStanza::Error::ServiceUnavailable;
    } else if (string == "subscription-required") {
        return QXmppStanza::Error::SubscriptionRequired;
    } else if (string == "undefined-condition") {
        return QXmppStanza::Error::UndefinedCondition;
    } else if (string == "unexpected-request") {
        return QXmppStanza::Error::UnexpectedRequest;
    }
    return std::nullopt;
}

QString typeToString(QXmppStanza::Error::Type type)
{
    switch (type) {
    case QXmppStanza::Error::NoType:
        return {};
    case QXmppStanza::Error::Cancel:
        return QStringLiteral("cancel");
    case QXmppStanza::Error::Continue:
        return QStringLiteral("continue");
    case QXmppStanza::Error::Modify:
        return QStringLiteral("modify");
    case QXmppStanza::Error::Auth:
        return QStringLiteral("auth");
    case QXmppStanza::Error::Wait:
        return QStringLiteral("wait");
    }
    return {};
}

std::optional<QXmppStanza::Error::Type> typeFromString(const QString &string)
{
    if (string == QStringLiteral("cancel")) {
        return QXmppStanza::Error::Cancel;
    } else if (string == QStringLiteral("continue")) {
        return QXmppStanza::Error::Continue;
    } else if (string == QStringLiteral("modify")) {
        return QXmppStanza::Error::Modify;
    } else if (string == QStringLiteral("auth")) {
        return QXmppStanza::Error::Auth;
    } else if (string == QStringLiteral("wait")) {
        return QXmppStanza::Error::Wait;
    }
    return std::nullopt;
}

}  // namespace QXmpp::Private

class QXmppExtendedAddressPrivate : public QSharedData
{
public:
    bool delivered;
    QString description;
    QString jid;
    QString type;
};

///
/// Constructs an empty extended address.
///
QXmppExtendedAddress::QXmppExtendedAddress()
    : d(new QXmppExtendedAddressPrivate())
{
    d->delivered = false;
}

/// Default copy-constructur
QXmppExtendedAddress::QXmppExtendedAddress(const QXmppExtendedAddress &other) = default;
/// Default move-constructur
QXmppExtendedAddress::QXmppExtendedAddress(QXmppExtendedAddress &&) = default;
QXmppExtendedAddress::~QXmppExtendedAddress() = default;
/// Default assignment operator
QXmppExtendedAddress &QXmppExtendedAddress::operator=(const QXmppExtendedAddress &other) = default;
/// Default assignment operator
QXmppExtendedAddress &QXmppExtendedAddress::operator=(QXmppExtendedAddress &&) = default;

///
/// Returns the human-readable description of the address.
///
QString QXmppExtendedAddress::description() const
{
    return d->description;
}

///
/// Sets the human-readable \a description of the address.
///
void QXmppExtendedAddress::setDescription(const QString &description)
{
    d->description = description;
}

///
/// Returns the JID of the address.
///
QString QXmppExtendedAddress::jid() const
{
    return d->jid;
}

///
/// Sets the JID of the address.
///
void QXmppExtendedAddress::setJid(const QString &jid)
{
    d->jid = jid;
}

///
/// Returns the type of the address.
///
QString QXmppExtendedAddress::type() const
{
    return d->type;
}

///
/// Sets the \a type of the address.
///
void QXmppExtendedAddress::setType(const QString &type)
{
    d->type = type;
}

///
/// Returns whether the stanza has been delivered to this address.
///
bool QXmppExtendedAddress::isDelivered() const
{
    return d->delivered;
}

///
/// Sets whether the stanza has been \a delivered to this address.
///
void QXmppExtendedAddress::setDelivered(bool delivered)
{
    d->delivered = delivered;
}

///
/// Checks whether this address is valid. The extended address is considered
/// to be valid if at least type and JID fields are non-empty.
///
bool QXmppExtendedAddress::isValid() const
{
    return !d->type.isEmpty() && !d->jid.isEmpty();
}

/// \cond
void QXmppExtendedAddress::parse(const QDomElement &element)
{
    d->delivered = element.attribute(QStringLiteral("delivered")) == QStringLiteral("true");
    d->description = element.attribute(QStringLiteral("desc"));
    d->jid = element.attribute(QStringLiteral("jid"));
    d->type = element.attribute(QStringLiteral("type"));
}

void QXmppExtendedAddress::toXml(QXmlStreamWriter *xmlWriter) const
{
    xmlWriter->writeStartElement(QStringLiteral("address"));
    if (d->delivered) {
        xmlWriter->writeAttribute(QStringLiteral("delivered"), QStringLiteral("true"));
    }
    if (!d->description.isEmpty()) {
        xmlWriter->writeAttribute(QStringLiteral("desc"), d->description);
    }
    xmlWriter->writeAttribute(QStringLiteral("jid"), d->jid);
    xmlWriter->writeAttribute(QStringLiteral("type"), d->type);
    xmlWriter->writeEndElement();
}
/// \endcond

class QXmppStanzaErrorPrivate : public QSharedData
{
public:
    int code = 0;
    QXmppStanza::Error::Type type = QXmppStanza::Error::NoType;
    QXmppStanza::Error::Condition condition = QXmppStanza::Error::NoCondition;
    QString text;
    QString by;
    QString redirectionUri;

    // XEP-0363: HTTP File Upload
    bool fileTooLarge = false;
    qint64 maxFileSize;
    QDateTime retryDate;
};

///
/// Default constructor
///
QXmppStanza::Error::Error()
    : d(new QXmppStanzaErrorPrivate)
{
}

/// Copy constructor
QXmppStanza::Error::Error(const QXmppStanza::Error &) = default;
/// Move constructor
QXmppStanza::Error::Error(QXmppStanza::Error &&) = default;

///
/// Initializes an error with a type, condition and text.
///
QXmppStanza::Error::Error(Type type, Condition cond, const QString &text)
    : d(new QXmppStanzaErrorPrivate)
{
    d->type = type;
    d->condition = cond;
    d->text = text;
}

///
/// Initializes an error with a type, condition and text (all from strings).
///
QXmppStanza::Error::Error(const QString &type, const QString &cond,
                          const QString &text)
    : d(new QXmppStanzaErrorPrivate)
{
    d->text = text;
    d->type = typeFromString(type).value_or(NoType);
    d->condition = conditionFromString(cond).value_or(NoCondition);
}

/// \cond
QXmppStanza::Error::Error(QSharedDataPointer<QXmppStanzaErrorPrivate> d)
    : d(std::move(d))
{
}
/// \endcond

/// Default destructor
QXmppStanza::Error::~Error() = default;
/// Copy operator
QXmppStanza::Error &QXmppStanza::Error::operator=(const QXmppStanza::Error &) = default;
/// Move operator
QXmppStanza::Error &QXmppStanza::Error::operator=(QXmppStanza::Error &&) = default;

///
/// Returns the human-readable description of the error.
///
QString QXmppStanza::Error::text() const
{
    return d->text;
}

///
/// Sets the description of the error.
///
void QXmppStanza::Error::setText(const QString &text)
{
    d->text = text;
}

///
/// Returns the error code.
///
int QXmppStanza::Error::code() const
{
    return d->code;
}

///
/// Sets the error code.
///
void QXmppStanza::Error::setCode(int code)
{
    d->code = code;
}

///
/// Returns the error condition.
///
/// The conditions QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect
/// can be used in combination with redirectUri().
///
QXmppStanza::Error::Condition QXmppStanza::Error::condition() const
{
    return d->condition;
}

///
/// Sets the error condition.
///
/// The conditions QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect
/// can be used in combination with setRedirectUri().
///
void QXmppStanza::Error::setCondition(Condition cond)
{
    d->condition = cond;
}

///
/// Returns the type of the error.
///
QXmppStanza::Error::Type QXmppStanza::Error::type() const
{
    return d->type;
}

///
/// Returns the optional JID of the creator of the error.
///
/// This is useful to ditinguish between errors generated by the local server
/// and by the remote server for example. However, the value is optional.
///
/// \since QXmpp 1.3
///
QString QXmppStanza::Error::by() const
{
    return d->by;
}

///
/// Sets the optional JID of the creator of the error.
///
/// This is useful to ditinguish between errors generated by the local server
/// and by the remote server for example. However, the value is optional.
///
/// \since QXmpp 1.3
///
void QXmppStanza::Error::setBy(const QString &by)
{
    d->by = by;
}

///
/// Sets the type of the error.
///
void QXmppStanza::Error::setType(QXmppStanza::Error::Type type)
{
    d->type = type;
}

///
/// Returns the optionally included redirection URI for the error conditions
/// QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect.
///
/// \sa setRedirectionUri()
///
/// \since QXmpp 1.3
///
QString QXmppStanza::Error::redirectionUri() const
{
    return d->redirectionUri;
}

///
/// Sets the optional redirection URI for the error conditions
/// QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect.
///
/// \sa redirectionUri()
///
/// \since QXmpp 1.3
///
void QXmppStanza::Error::setRedirectionUri(const QString &redirectionUri)
{
    d->redirectionUri = redirectionUri;
}

///
/// Returns true, if an HTTP File Upload failed, because the file was too
/// large.
///
/// \since QXmpp 1.1
///
bool QXmppStanza::Error::fileTooLarge() const
{
    return d->fileTooLarge;
}

///
/// Sets whether the requested file for HTTP File Upload was too large.
///
/// You should also set maxFileSize in this case.
///
/// \since QXmpp 1.1
///
void QXmppStanza::Error::setFileTooLarge(bool fileTooLarge)
{
    d->fileTooLarge = fileTooLarge;
}

///
/// Returns the maximum file size allowed for uploading via. HTTP File Upload.
///
/// \since QXmpp 1.1
///
qint64 QXmppStanza::Error::maxFileSize() const
{
    return d->maxFileSize;
}

///
/// Sets the maximum file size allowed for uploading via. HTTP File Upload.
///
/// This sets fileTooLarge to true.
///
/// \since QXmpp 1.1
///
void QXmppStanza::Error::setMaxFileSize(qint64 maxFileSize)
{
    setFileTooLarge(true);
    d->maxFileSize = maxFileSize;
}

///
/// Returns when to retry the upload request via. HTTP File Upload.
///
/// \since QXmpp 1.1
///
QDateTime QXmppStanza::Error::retryDate() const
{
    return d->retryDate;
}

///
/// Sets the datetime when the client can retry to request the upload slot.
///
void QXmppStanza::Error::setRetryDate(const QDateTime &retryDate)
{
    d->retryDate = retryDate;
}

/// \cond
void QXmppStanza::Error::parse(const QDomElement &errorElement)
{
    d->code = errorElement.attribute(QStringLiteral("code")).toInt();
    d->type = typeFromString(errorElement.attribute(QStringLiteral("type"))).value_or(NoType);
    d->by = errorElement.attribute(QStringLiteral("by"));

    for (auto element = errorElement.firstChildElement();
         !element.isNull();
         element = element.nextSiblingElement()) {
        if (element.namespaceURI() == ns_stanza) {
            if (element.tagName() == QStringLiteral("text")) {
                d->text = element.text();
            } else {
                d->condition = conditionFromString(element.tagName()).value_or(NoCondition);

                // redirection URI
                if (d->condition == Gone || d->condition == Redirect) {
                    d->redirectionUri = element.text();

                    // .text() returns empty string if nothing was set
                    if (d->redirectionUri.isEmpty()) {
                        d->redirectionUri.clear();
                    }
                }
            }
        } else if (element.namespaceURI() == ns_http_upload) {
            // XEP-0363: HTTP File Upload
            // file is too large
            if (element.tagName() == QStringLiteral("file-too-large")) {
                d->fileTooLarge = true;
                d->maxFileSize = element.firstChildElement(QStringLiteral("max-file-size"))
                                     .text()
                                     .toLongLong();
                // retry later
            } else if (element.tagName() == QStringLiteral("retry")) {
                d->retryDate = QXmppUtils::datetimeFromString(
                    element.attribute(QStringLiteral("stamp")));
            }
        }
    }
}

void QXmppStanza::Error::toXml(QXmlStreamWriter *writer) const
{
    if (d->condition == NoCondition && d->type == NoType) {
        return;
    }

    writer->writeStartElement(QStringLiteral("error"));
    helperToXmlAddAttribute(writer, QStringLiteral("by"), d->by);
    if (d->type != NoType) {
        writer->writeAttribute(QStringLiteral("type"), typeToString(d->type));
    }

    if (d->code > 0) {
        helperToXmlAddAttribute(writer, QStringLiteral("code"), QString::number(d->code));
    }

    if (d->condition != NoCondition) {
        writer->writeStartElement(conditionToString(d->condition));
        writer->writeDefaultNamespace(ns_stanza);

        // redirection URI
        if (!d->redirectionUri.isEmpty() && (d->condition == Gone || d->condition == Redirect)) {
            writer->writeCharacters(d->redirectionUri);
        }

        writer->writeEndElement();
    }
    if (!d->text.isEmpty()) {
        writer->writeStartElement(QStringLiteral("text"));
        writer->writeAttribute(QStringLiteral("xml:lang"), QStringLiteral("en"));
        writer->writeDefaultNamespace(ns_stanza);
        writer->writeCharacters(d->text);
        writer->writeEndElement();
    }

    // XEP-0363: HTTP File Upload
    if (d->fileTooLarge) {
        writer->writeStartElement(QStringLiteral("file-too-large"));
        writer->writeDefaultNamespace(ns_http_upload);
        helperToXmlAddTextElement(writer, QStringLiteral("max-file-size"),
                                  QString::number(d->maxFileSize));
        writer->writeEndElement();
    } else if (!d->retryDate.isNull() && d->retryDate.isValid()) {
        writer->writeStartElement(QStringLiteral("retry"));
        writer->writeDefaultNamespace(ns_http_upload);
        writer->writeAttribute(QStringLiteral("stamp"),
                               QXmppUtils::datetimeToString(d->retryDate));
        writer->writeEndElement();
    }

    writer->writeEndElement();
}
/// \endcond

///
/// \class QXmppE2eeMetadata
///
/// \brief The QXmppE2eeMetadata class contains data used for end-to-end
/// encryption purposes.
///
/// \since QXmpp 1.5
///

class QXmppE2eeMetadataPrivate : public QSharedData
{
public:
    QXmpp::EncryptionMethod encryption;
    QByteArray senderKey;

    // XEP-0420: Stanza Content Encryption
    QDateTime sceTimestamp;
};

///
/// Constructs a class for end-to-end encryption metadata.
///
QXmppE2eeMetadata::QXmppE2eeMetadata()
    : d(new QXmppE2eeMetadataPrivate)
{
}

/// \cond
QXmppE2eeMetadata::QXmppE2eeMetadata(QSharedDataPointer<QXmppE2eeMetadataPrivate> d)
    : d(d)
{
}
/// \endcond

/// Copy-constructor.
QXmppE2eeMetadata::QXmppE2eeMetadata(const QXmppE2eeMetadata &other) = default;
/// Move-constructor.
QXmppE2eeMetadata::QXmppE2eeMetadata(QXmppE2eeMetadata &&) = default;
QXmppE2eeMetadata::~QXmppE2eeMetadata() = default;
/// Assignment operator.
QXmppE2eeMetadata &QXmppE2eeMetadata::operator=(const QXmppE2eeMetadata &other) = default;
/// Assignment move-operator.
QXmppE2eeMetadata &QXmppE2eeMetadata::operator=(QXmppE2eeMetadata &&) = default;

///
/// Returns the used encryption protocol.
///
/// \return the encryption protocol
///
QXmpp::EncryptionMethod QXmppE2eeMetadata::encryption() const
{
    return d->encryption;
}

///
/// Sets the used encryption protocol.
///
/// \param encryption encryption protocol
///
void QXmppE2eeMetadata::setEncryption(QXmpp::EncryptionMethod encryption)
{
    d->encryption = encryption;
}

///
/// Returns the ID of this stanza's sender's public long-term key.
///
/// The sender key ID is not part of a transmitted stanza and thus not de- /
/// serialized.
/// Instead, the key ID is set by an encryption protocol such as
/// \xep{0384, OMEMO Encryption} during decryption.
/// It can be used by trust management protocols such as
/// \xep{0450, Automatic Trust Management (ATM)}.
///
/// \return the ID of the sender's key
///
/// \since QXmpp 1.5
///
QByteArray QXmppE2eeMetadata::senderKey() const
{
    return d->senderKey;
}

///
/// Sets the ID of this stanza's sender's public long-term key.
///
/// The sender key ID is not part of a transmitted stanza and thus not de- /
/// serialized.
/// Instead, it is set by an encryption protocol such as
/// \xep{0384, OMEMO Encryption} during decryption.
/// It can be used by trust management protocols such as
/// \xep{0450, Automatic Trust Management (ATM)}.
///
/// \param keyId ID of the sender's key
///
/// \since QXmpp 1.5
///
void QXmppE2eeMetadata::setSenderKey(const QByteArray &keyId)
{
    d->senderKey = keyId;
}

///
/// Returns the timestamp affix element's content as defined by
/// \xep{0420, Stanza Content Encryption} (SCE).
///
/// The SCE timestamp is part of an encrypted stanza's SCE envelope,
/// not an unencrypted direct child of a transmitted stanza and thus not de- /
/// serialized by it.
/// Instead, it is set by an encryption protocol such as
/// \xep{0384, OMEMO Encryption} after decryption.
/// It can be used by trust management protocols such as
/// \xep{0450, Automatic Trust Management (ATM)}.
///
/// \since QXmpp 1.5
///
QDateTime QXmppE2eeMetadata::sceTimestamp() const
{
    return d->sceTimestamp;
}

///
/// Sets the timestamp affix element's content as defined by
/// \xep{0420, Stanza Content Encryption} (SCE).
///
/// The SCE timestamp is part of an encrypted stanza's SCE envelope,
/// not an unencrypted direct child of a transmitted stanza and thus not de- /
/// serialized by it.
/// Instead, it is set by an encryption protocol such as
/// \xep{0384, OMEMO Encryption} after decryption.
/// It can be used by trust management protocols such as
/// \xep{0450, Automatic Trust Management (ATM)}.
///
/// \since QXmpp 1.5
///
void QXmppE2eeMetadata::setSceTimestamp(const QDateTime &timestamp)
{
    d->sceTimestamp = timestamp;
}

class QXmppStanzaPrivate : public QSharedData
{
public:
    QString to;
    QString from;
    QString id;
    QString lang;
    QSharedDataPointer<QXmppStanzaErrorPrivate> error;
    QXmppElementList extensions;
    QList<QXmppExtendedAddress> extendedAddresses;
    QSharedDataPointer<QXmppE2eeMetadataPrivate> e2eeMetadata;
};

///
/// Constructs a QXmppStanza with the specified sender and recipient.
///
/// \param from
/// \param to
///
QXmppStanza::QXmppStanza(const QString &from, const QString &to)
    : d(new QXmppStanzaPrivate)
{
    d->to = to;
    d->from = from;
}

/// Constructs a copy of \a other.
QXmppStanza::QXmppStanza(const QXmppStanza &other) = default;
/// Move constructor.
QXmppStanza::QXmppStanza(QXmppStanza &&) = default;
/// Destroys a QXmppStanza.
QXmppStanza::~QXmppStanza() = default;
/// Assigns \a other to this stanza.
QXmppStanza &QXmppStanza::operator=(const QXmppStanza &other) = default;
/// Move-assignment operator.
QXmppStanza &QXmppStanza::operator=(QXmppStanza &&) = default;

///
/// Returns the stanza's recipient JID.
///
QString QXmppStanza::to() const
{
    return d->to;
}

///
/// Sets the stanza's recipient JID.
///
/// \param to
///
void QXmppStanza::setTo(const QString &to)
{
    d->to = to;
}

///
/// Returns the stanza's sender JID.
///
QString QXmppStanza::from() const
{
    return d->from;
}

///
/// Sets the stanza's sender JID.
///
/// \param from
///
void QXmppStanza::setFrom(const QString &from)
{
    d->from = from;
}

///
/// Returns the stanza's identifier.
///
QString QXmppStanza::id() const
{
    return d->id;
}

///
/// Sets the stanza's identifier.
///
/// \param id
///
void QXmppStanza::setId(const QString &id)
{
    d->id = id;
}

///
/// Returns the stanza's language.
///
QString QXmppStanza::lang() const
{
    return d->lang;
}

///
/// Sets the stanza's language.
///
/// \param lang
///
void QXmppStanza::setLang(const QString &lang)
{
    d->lang = lang;
}

///
/// Returns the stanza's error.
///
/// If the stanza has no error a default constructed QXmppStanza::Error is returned.
///
QXmppStanza::Error QXmppStanza::error() const
{
    return d->error ? Error { d->error } : Error();
}

///
/// Returns the stanza's error.
///
/// \since QXmpp 1.5
///
std::optional<QXmppStanza::Error> QXmppStanza::errorOptional() const
{
    if (d->error) {
        return Error { d->error };
    }
    return {};
}

///
/// Sets the stanza's error.
///
/// \param error
///
void QXmppStanza::setError(const QXmppStanza::Error &error)
{
    d->error = error.d;
}

///
/// Sets the stanza's error.
///
/// If you set an empty optional, this will remove the error.
///
/// \since QXmpp 1.5
///
void QXmppStanza::setError(const std::optional<Error> &error)
{
    if (error) {
        d->error = error->d;
    } else {
        d->error = nullptr;
    }
}

///
/// Returns the stanza's "extensions".
///
/// Extensions are XML elements which are not handled internally by QXmpp.
///
QXmppElementList QXmppStanza::extensions() const
{
    return d->extensions;
}

///
/// Sets the stanza's "extensions".
///
/// \param extensions
///
void QXmppStanza::setExtensions(const QXmppElementList &extensions)
{
    d->extensions = extensions;
}

///
/// Returns the stanza's extended addresses as defined by \xep{0033, Extended
/// Stanza Addressing}.
///
QList<QXmppExtendedAddress> QXmppStanza::extendedAddresses() const
{
    return d->extendedAddresses;
}

///
/// Sets the stanza's extended addresses as defined by \xep{0033, Extended
/// Stanza Addressing}.
///
void QXmppStanza::setExtendedAddresses(const QList<QXmppExtendedAddress> &addresses)
{
    d->extendedAddresses = addresses;
}

///
/// Returns additional data for end-to-end encryption purposes.
///
/// \since QXmpp 1.5
///
std::optional<QXmppE2eeMetadata> QXmppStanza::e2eeMetadata() const
{
    if (d->e2eeMetadata) {
        return QXmppE2eeMetadata(d->e2eeMetadata);
    }
    return {};
}

///
/// Sets additional data for end-to-end encryption purposes.
///
/// \since QXmpp 1.5
///
void QXmppStanza::setE2eeMetadata(const std::optional<QXmppE2eeMetadata> &e2eeMetadata)
{
    if (e2eeMetadata) {
        d->e2eeMetadata = e2eeMetadata->d;
    } else {
        d->e2eeMetadata = nullptr;
    }
}

/// \cond
void QXmppStanza::generateAndSetNextId()
{
    // get back
    ++s_uniqeIdNo;
    d->id = "qxmpp" + QString::number(s_uniqeIdNo);
}

void QXmppStanza::parse(const QDomElement &element)
{
    d->from = element.attribute("from");
    d->to = element.attribute("to");
    d->id = element.attribute("id");
    d->lang = element.attribute("lang");

    QDomElement errorElement = element.firstChildElement("error");
    if (!errorElement.isNull()) {
        Error error;
        error.parse(errorElement);
        d->error = error.d;
    }

    // XEP-0033: Extended Stanza Addressing
    for (auto addressElement = element.firstChildElement("addresses").firstChildElement("address");
         !addressElement.isNull();
         addressElement = addressElement.nextSiblingElement("address")) {
        QXmppExtendedAddress address;
        address.parse(addressElement);
        if (address.isValid()) {
            d->extendedAddresses << address;
        }
    }
}

void QXmppStanza::extensionsToXml(QXmlStreamWriter *xmlWriter, QXmpp::SceMode sceMode) const
{
    // XEP-0033: Extended Stanza Addressing
    if (sceMode & QXmpp::ScePublic && !d->extendedAddresses.isEmpty()) {
        xmlWriter->writeStartElement("addresses");
        xmlWriter->writeDefaultNamespace(ns_extended_addressing);
        for (const auto &address : d->extendedAddresses) {
            address.toXml(xmlWriter);
        }
        xmlWriter->writeEndElement();
    }

    // other extensions
    for (const auto &extension : d->extensions) {
        extension.toXml(xmlWriter);
    }
}

/// \endcond