Implement XEP-0444: Message Reactions (#492)

https://xmpp.org/extensions/xep-0444.html

6 files changed, 223 insertions, 0 deletions

diff --git a/src/base/QXmppConstants.cpp b/src/base/QXmppConstants.cpp
index 0a8152f9..3d1afe88 100644
--- a/src/base/QXmppConstants.cpp
+++ b/src/base/QXmppConstants.cpp
@@ -199,6 +199,8 @@ const char *ns_mix_misc = "urn:xmpp:mix:misc:0";
 const char *ns_fallback_indication = "urn:xmpp:fallback:0";
 // XEP-0434: Trust Messages (TM)
 const char *ns_tm = "urn:xmpp:tm:1";
+// XEP-0444: Message Reactions
+const char *ns_reactions = "urn:xmpp:reactions:0";
 // XEP-0446: File metadata element
 const char *ns_file_metadata = "urn:xmpp:file:metadata:0";
 // XEP-0447: Stateless file sharing
diff --git a/src/base/QXmppConstants_p.h b/src/base/QXmppConstants_p.h
index f5086cc9..88489e0c 100644
--- a/src/base/QXmppConstants_p.h
+++ b/src/base/QXmppConstants_p.h
@@ -211,6 +211,8 @@ extern const char *ns_mix_misc;
 extern const char *ns_fallback_indication;
 // XEP-0434: Trust Messages (TM)
 extern const char *ns_tm;
+// XEP-0444: Message Reactions
+extern const char *ns_reactions;
 // XEP-0446: File metadata element
 extern const char *ns_file_metadata;
 // XEP-0447: Stateless file sharing
diff --git a/src/base/QXmppMessage.cpp b/src/base/QXmppMessage.cpp
index 7998598c..c0923d22 100644
--- a/src/base/QXmppMessage.cpp
+++ b/src/base/QXmppMessage.cpp
@@ -11,6 +11,7 @@
 #include "QXmppConstants_p.h"
 #include "QXmppFileShare.h"
 #include "QXmppGlobal_p.h"
+#include "QXmppMessageReaction.h"
 #include "QXmppMixInvitation.h"
 #ifdef BUILD_OMEMO
 #include "QXmppOmemoElement_p.h"
@@ -154,6 +155,9 @@ public:
     // XEP-0434: Trust Messages (TM)
     std::optional<QXmppTrustMessageElement> trustMessageElement;
 
+    // XEP-0444: Message Reactions
+    std::optional<QXmppMessageReaction> reaction;
+
     // XEP-0448: Encryption for stateless file sharing
     QVector<QXmppFileShare> sharedFiles;
 };
@@ -1239,6 +1243,32 @@ void QXmppMessage::setTrustMessageElement(const std::optional<QXmppTrustMessageE
 }
 
 ///
+/// Returns a reaction to a message as defined by \xep{0444, Message Reactions}.
+///
+/// \since QXmpp 1.5
+///
+std::optional<QXmppMessageReaction> QXmppMessage::reaction() const
+{
+    return d->reaction;
+}
+
+///
+/// Sets a reaction to a message as defined by \xep{0444, Message Reactions}.
+///
+/// The corresponding hint must be set manually:
+/// \code
+/// QXmppMessage message;
+/// message.addHint(QXmppMessage::Store);
+/// \endcode
+///
+/// \since QXmpp 1.5
+///
+void QXmppMessage::setReaction(const std::optional<QXmppMessageReaction> &reaction)
+{
+    d->reaction = reaction;
+}
+
+///
 /// Returns the via \xep{0447, Stateless file sharing} shared files attached to this message.
 ///
 /// \since QXmpp 1.5
@@ -1544,6 +1574,13 @@ bool QXmppMessage::parseExtension(const QDomElement &element, QXmpp::SceMode sce
             d->trustMessageElement = trustMessageElement;
             return true;
         }
+        // XEP-0444: Message Reactions
+        if (QXmppMessageReaction::isMessageReaction(element)) {
+            QXmppMessageReaction reaction;
+            reaction.parse(element);
+            d->reaction = std::move(reaction);
+            return true;
+        }
         // XEP-0448: Stateless file sharing
         if (checkElement(element, QStringLiteral("file-sharing"), ns_sfs)) {
             QXmppFileShare share;
@@ -1800,6 +1837,11 @@ void QXmppMessage::serializeExtensions(QXmlStreamWriter *writer, QXmpp::SceMode
             d->trustMessageElement->toXml(writer);
         }
 
+        // XEP-0444: Message Reactions
+        if (d->reaction) {
+            d->reaction->toXml(writer);
+        }
+
         // XEP-0448: Stateless file sharing
         for (const auto &fileShare : d->sharedFiles) {
             fileShare.toXml(writer);
diff --git a/src/base/QXmppMessage.h b/src/base/QXmppMessage.h
index 899f477e..be9e9b96 100644
--- a/src/base/QXmppMessage.h
+++ b/src/base/QXmppMessage.h
@@ -18,6 +18,7 @@
 
 class QXmppMessagePrivate;
 class QXmppBitsOfBinaryDataList;
+class QXmppMessageReaction;
 class QXmppMixInvitation;
 #ifdef BUILD_OMEMO
 class QXmppOmemoElement;
@@ -253,6 +254,10 @@ public:
     std::optional<QXmppTrustMessageElement> trustMessageElement() const;
     void setTrustMessageElement(const std::optional<QXmppTrustMessageElement> &trustMessageElement);
 
+    // XEP-0444: Message Reactions
+    std::optional<QXmppMessageReaction> reaction() const;
+    void setReaction(const std::optional<QXmppMessageReaction> &reaction);
+
     // XEP-0447: Stateless file sharing
     const QVector<QXmppFileShare> &sharedFiles() const;
     void setSharedFiles(const QVector<QXmppFileShare> &sharedFiles);
diff --git a/src/base/QXmppMessageReaction.cpp b/src/base/QXmppMessageReaction.cpp
new file mode 100644
index 00000000..4bf9dcb3
--- /dev/null
+++ b/src/base/QXmppMessageReaction.cpp
@@ -0,0 +1,132 @@
+// SPDX-FileCopyrightText: 2022 Melvin Keskin <melvo@olomono.de>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "QXmppMessageReaction.h"
+
+#include "QXmppConstants_p.h"
+#include "QXmppUtils.h"
+
+#include <QDomElement>
+
+class QXmppMessageReactionPrivate : public QSharedData
+{
+public:
+    QString messageId;
+    QVector<QString> emojis;
+};
+
+///
+/// \class QXmppMessageReaction
+///
+/// \brief The QXmppMessageReaction class represents a reaction to a message in the form of emojis
+/// as specified by \xep{0444, Message Reactions}.
+///
+/// \since QXmpp 1.5
+///
+
+///
+/// Constructs a message reaction.
+///
+QXmppMessageReaction::QXmppMessageReaction()
+    : d(new QXmppMessageReactionPrivate)
+{
+}
+
+QXMPP_PRIVATE_DEFINE_RULE_OF_SIX(QXmppMessageReaction)
+
+///
+/// Returns the ID of the message for that the reaction is sent.
+///
+/// For a group chat message, \code QXmppMessage::stanzaId() \endcode is used.
+///
+/// For other message types, \code QXmppMessage::originId() \endcode is used.
+/// If that is not available, \code QXmppMessage::id() \endcode is used.
+///
+/// \return the message's ID
+///
+QString QXmppMessageReaction::messageId() const
+{
+    return d->messageId;
+}
+
+///
+/// Sets the ID of the message for that the reaction is sent.
+///
+/// For a group chat message, \code QXmppMessage::stanzaId() \endcode must be used.
+/// If there is no such ID, a message reaction must not be sent.
+///
+/// For other message types, \code QXmppMessage::originId() \endcode should be used.
+/// If that is not available, \code QXmppMessage::id() \endcode should be used.
+///
+/// \param messageId message's ID
+///
+void QXmppMessageReaction::setMessageId(const QString &messageId)
+{
+    d->messageId = messageId;
+}
+
+///
+/// Returns the emojis in reaction to a message.
+///
+/// \return the emoji reactions
+///
+QVector<QString> QXmppMessageReaction::emojis() const
+{
+    return d->emojis;
+}
+
+///
+/// Sets the emojis in reaction to a message.
+///
+/// Each reaction should only consist of unicode codepoints that can be displayed as a single emoji.
+/// Duplicates are not allowed.
+///
+/// \param emojis emoji reactions
+///
+void QXmppMessageReaction::setEmojis(const QVector<QString> &emojis)
+{
+    d->emojis = emojis;
+}
+
+/// \cond
+void QXmppMessageReaction::parse(const QDomElement &element)
+{
+    d->messageId = element.attribute(QStringLiteral("id"));
+
+    for (auto childElement = element.firstChildElement();
+         !childElement.isNull();
+         childElement = childElement.nextSiblingElement()) {
+        d->emojis.append(childElement.text());
+    }
+
+    // Remove duplicate emojis.
+    std::sort(d->emojis.begin(), d->emojis.end());
+    d->emojis.erase(std::unique(d->emojis.begin(), d->emojis.end()), d->emojis.end());
+}
+
+void QXmppMessageReaction::toXml(QXmlStreamWriter *writer) const
+{
+    writer->writeStartElement(QStringLiteral("reactions"));
+    writer->writeDefaultNamespace(ns_reactions);
+    writer->writeAttribute(QStringLiteral("id"), d->messageId);
+
+    for (const auto &reaction : d->emojis) {
+        helperToXmlAddTextElement(writer, QStringLiteral("reaction"), reaction);
+    }
+    writer->writeEndElement();
+}
+/// \endcond
+
+///
+/// Determines whether the given DOM element is a message reaction element.
+///
+/// \param element DOM element being checked
+///
+/// \return true if element is a message reaction element, otherwise false
+///
+bool QXmppMessageReaction::isMessageReaction(const QDomElement &element)
+{
+    return element.tagName() == QStringLiteral("reactions") &&
+        element.namespaceURI() == ns_reactions;
+}
diff --git a/src/base/QXmppMessageReaction.h b/src/base/QXmppMessageReaction.h
new file mode 100644
index 00000000..ce8fdfc1
--- /dev/null
+++ b/src/base/QXmppMessageReaction.h
@@ -0,0 +1,40 @@
+// SPDX-FileCopyrightText: 2022 Melvin Keskin <melvo@olomono.de>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#ifndef QXMPPMESSAGEREACTION_H
+#define QXMPPMESSAGEREACTION_H
+
+#include "QXmppGlobal.h"
+
+#include <QSharedDataPointer>
+
+class QDomElement;
+class QXmlStreamWriter;
+class QXmppMessageReactionPrivate;
+
+class QXMPP_EXPORT QXmppMessageReaction
+{
+public:
+    QXmppMessageReaction();
+
+    QXMPP_PRIVATE_DECLARE_RULE_OF_SIX(QXmppMessageReaction)
+
+    QString messageId() const;
+    void setMessageId(const QString &messageId);
+
+    QVector<QString> emojis() const;
+    void setEmojis(const QVector<QString> &emojis);
+
+    /// \cond
+    void parse(const QDomElement &element);
+    void toXml(QXmlStreamWriter *writer) const;
+    /// \endcond
+
+    static bool isMessageReaction(const QDomElement &element);
+
+private:
+    QSharedDataPointer<QXmppMessageReactionPrivate> d;
+};
+
+#endif  // QXMPPMESSAGEREACTION_H