Implement XEP-0444: Message Reactions (#492)

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

12 files changed, 372 insertions, 0 deletions

diff --git a/doc/doap.xml b/doc/doap.xml
index a21293d4..c9b9e3e1 100644
--- a/doc/doap.xml
+++ b/doc/doap.xml
@@ -592,6 +592,14 @@ SPDX-License-Identifier: CC0-1.0
     </implements>
     <implements>
       <xmpp:SupportedXep>
+        <xmpp:xep rdf:resource='https://xmpp.org/extensions/xep-0444.html'/>
+        <xmpp:status>complete</xmpp:status>
+        <xmpp:version>0.1</xmpp:version>
+        <xmpp:since>1.5</xmpp:since>
+      </xmpp:SupportedXep>
+    </implements>
+    <implements>
+      <xmpp:SupportedXep>
         <xmpp:xep rdf:resource='https://xmpp.org/extensions/xep-0446.html'/>
         <xmpp:status>complete</xmpp:status>
         <xmpp:version>0.2</xmpp:version>
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 089039b7..1b4595f5 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -54,6 +54,7 @@ set(INSTALL_HEADER_FILES
     base/QXmppLogger.h
     base/QXmppMamIq.h
     base/QXmppMessage.h
+    base/QXmppMessageReaction.h
     base/QXmppMixInfoItem.h
     base/QXmppMixInvitation.h
     base/QXmppMixIq.h
@@ -183,6 +184,7 @@ set(SOURCE_FILES
     base/QXmppLogger.cpp
     base/QXmppMamIq.cpp
     base/QXmppMessage.cpp
+    base/QXmppMessageReaction.cpp
     base/QXmppMixInvitation.cpp
     base/QXmppMixIq.cpp
     base/QXmppMixItems.cpp
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
diff --git a/src/client/QXmppClient.cpp b/src/client/QXmppClient.cpp
index f8be81b0..f69bc29b 100644
--- a/src/client/QXmppClient.cpp
+++ b/src/client/QXmppClient.cpp
@@ -112,6 +112,8 @@ QStringList QXmppClientPrivate::discoveryFeatures()
         ns_spoiler,
         // XEP-0428: Fallback Indication
         ns_fallback_indication,
+        // XEP-0444: Message Reactions
+        ns_reactions,
     };
 }
 /// \endcond
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index e43b50c6..3e55e4d9 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -43,6 +43,7 @@ add_simple_test(qxmppmammanager)
 add_simple_test(qxmppmixinvitation)
 add_simple_test(qxmppmixitems)
 add_simple_test(qxmppmessage)
+add_simple_test(qxmppmessagereaction)
 add_simple_test(qxmppmessagereceiptmanager)
 add_simple_test(qxmppmixiq)
 add_simple_test(qxmppnonsaslauthiq)
diff --git a/tests/qxmppmessage/tst_qxmppmessage.cpp b/tests/qxmppmessage/tst_qxmppmessage.cpp
index 1aa2c673..ee964a4c 100644
--- a/tests/qxmppmessage/tst_qxmppmessage.cpp
+++ b/tests/qxmppmessage/tst_qxmppmessage.cpp
@@ -8,6 +8,7 @@
 #include "QXmppBitsOfBinaryDataList.h"
 #include "QXmppEncryptedFileSource.h"
 #include "QXmppMessage.h"
+#include "QXmppMessageReaction.h"
 #include "QXmppMixInvitation.h"
 #include "QXmppOutOfBandUrl.h"
 #include "QXmppTrustMessageElement.h"
@@ -53,6 +54,7 @@ private slots:
     void testSlashMe();
     void testMixInvitation();
     void testTrustMessageElement();
+    void testReaction();
     void testE2eeFallbackBody();
     void testFileSharing();
     void testEncryptedFileSource();
@@ -1129,6 +1131,30 @@ void tst_QXmppMessage::testTrustMessageElement()
     QVERIFY(message2.trustMessageElement());
 }
 
+void tst_QXmppMessage::testReaction()
+{
+    const QByteArray xml(
+        "<message id=\"96d73204-a57a-11e9-88b8-4889e7820c76\" to=\"romeo@capulet.net/orchard\" type=\"chat\">"
+        "<store xmlns=\"urn:xmpp:hints\"/>"
+        "<reactions xmlns=\"urn:xmpp:reactions:0\" id=\"744f6e18-a57a-11e9-a656-4889e7820c76\">"
+        "<reaction>🐢</reaction>"
+        "<reaction>👋</reaction>"
+        "</reactions>"
+        "</message>");
+
+    QXmppMessage message1;
+    QVERIFY(!message1.reaction());
+
+    parsePacket(message1, xml);
+    QVERIFY(message1.reaction());
+    serializePacket(message1, xml);
+
+    QXmppMessage message2;
+    message2.addHint(QXmppMessage::Store);
+    message2.setReaction(QXmppMessageReaction());
+    QVERIFY(message2.reaction());
+}
+
 void tst_QXmppMessage::testE2eeFallbackBody()
 {
     const QByteArray xml(
diff --git a/tests/qxmppmessagereaction/tst_qxmppmessagereaction.cpp b/tests/qxmppmessagereaction/tst_qxmppmessagereaction.cpp
new file mode 100644
index 00000000..8acbe6c9
--- /dev/null
+++ b/tests/qxmppmessagereaction/tst_qxmppmessagereaction.cpp
@@ -0,0 +1,110 @@
+// SPDX-FileCopyrightText: 2022 Melvin Keskin <melvo@olomono.de>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "QXmppMessageReaction.h"
+
+#include "util.h"
+#include <QObject>
+
+class tst_QXmppMessageReaction : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void testIsMessageReaction_data();
+    void testIsMessageReaction();
+    void testMessageReaction();
+    void testMessageReactionWithDuplicateEmojis();
+    void testMessageReactionRemoval();
+};
+
+void tst_QXmppMessageReaction::testIsMessageReaction_data()
+{
+    QTest::addColumn<QByteArray>("xml");
+    QTest::addColumn<bool>("isValid");
+
+    QTest::newRow("valid")
+        << QByteArrayLiteral("<reactions xmlns=\"urn:xmpp:reactions:0\"/>")
+        << true;
+    QTest::newRow("invalidTag")
+        << QByteArrayLiteral("<invalid xmlns=\"urn:xmpp:reactions:0\"/>")
+        << false;
+    QTest::newRow("invalidNamespace")
+        << QByteArrayLiteral("<reactions xmlns=\"invalid\"/>")
+        << false;
+}
+
+void tst_QXmppMessageReaction::testIsMessageReaction()
+{
+    QFETCH(QByteArray, xml);
+    QFETCH(bool, isValid);
+
+    QCOMPARE(QXmppMessageReaction::isMessageReaction(xmlToDom(xml)), isValid);
+}
+
+void tst_QXmppMessageReaction::testMessageReaction()
+{
+    const QByteArray xml(
+        "<reactions xmlns=\"urn:xmpp:reactions:0\" id=\"744f6e18-a57a-11e9-a656-4889e7820c76\">"
+        "<reaction>🐢</reaction>"
+        "<reaction>👋</reaction>"
+        "</reactions>");
+
+    QXmppMessageReaction reaction1;
+    QVERIFY(reaction1.messageId().isEmpty());
+    QVERIFY(reaction1.emojis().isEmpty());
+
+    parsePacket(reaction1, xml);
+    QCOMPARE(reaction1.messageId(), QStringLiteral("744f6e18-a57a-11e9-a656-4889e7820c76"));
+    QCOMPARE(reaction1.emojis().at(0), QStringLiteral("🐢"));
+    QCOMPARE(reaction1.emojis().at(1), QStringLiteral("👋"));
+
+    serializePacket(reaction1, xml);
+
+    QXmppMessageReaction reaction2;
+    reaction2.setMessageId(QStringLiteral("744f6e18-a57a-11e9-a656-4889e7820c76"));
+    reaction2.setEmojis({ QStringLiteral("🐢"), QStringLiteral("👋") });
+
+    QCOMPARE(reaction1.messageId(), QStringLiteral("744f6e18-a57a-11e9-a656-4889e7820c76"));
+    QCOMPARE(reaction1.emojis().at(0), QStringLiteral("🐢"));
+    QCOMPARE(reaction1.emojis().at(1), QStringLiteral("👋"));
+
+    serializePacket(reaction2, xml);
+}
+
+void tst_QXmppMessageReaction::testMessageReactionWithDuplicateEmojis()
+{
+    const QByteArray xml(
+        "<reactions xmlns=\"urn:xmpp:reactions:0\" id=\"744f6e18-a57a-11e9-a656-4889e7820c76\">"
+        "<reaction>🐢</reaction>"
+        "<reaction>👋</reaction>"
+        "<reaction>🐢</reaction>"
+        "<reaction>👋</reaction>"
+        "</reactions>");
+
+    QXmppMessageReaction reaction;
+
+    parsePacket(reaction, xml);
+    QCOMPARE(reaction.messageId(), QStringLiteral("744f6e18-a57a-11e9-a656-4889e7820c76"));
+    QCOMPARE(reaction.emojis().size(), 2);
+    QCOMPARE(reaction.emojis().at(0), QStringLiteral("🐢"));
+    QCOMPARE(reaction.emojis().at(1), QStringLiteral("👋"));
+}
+
+void tst_QXmppMessageReaction::testMessageReactionRemoval()
+{
+    const QByteArray xml(
+        "<reactions xmlns=\"urn:xmpp:reactions:0\" id=\"744f6e18-a57a-11e9-a656-4889e7820c76\"/>");
+
+    QXmppMessageReaction reaction;
+
+    parsePacket(reaction, xml);
+    QCOMPARE(reaction.messageId(), QStringLiteral("744f6e18-a57a-11e9-a656-4889e7820c76"));
+    QCOMPARE(reaction.emojis().size(), 0);
+
+    serializePacket(reaction, xml);
+}
+
+QTEST_MAIN(tst_QXmppMessageReaction)
+#include "tst_qxmppmessagereaction.moc"