Implement XEP-0334: Message Processing Hints

This implements parsing and serialization of XEP-0334: Message
Processing Hints in version 0.3.0.

https://xmpp.org/extensions/xep-0334.html

Co-authored-by: Juan Aragon <jaaragont@gmail.com>
Co-authored-by: Sam Truscott <sam@wumpus.co.uk>

4 files changed, 74 insertions, 0 deletions

diff --git a/src/base/QXmppConstants.cpp b/src/base/QXmppConstants.cpp
index 80c97b56..92ff8689 100644
--- a/src/base/QXmppConstants.cpp
+++ b/src/base/QXmppConstants.cpp
@@ -133,6 +133,8 @@ const char* ns_mam = "urn:xmpp:mam:1";
 const char* ns_idle = "urn:xmpp:idle:1";
 // XEP-0333: Chat Markers
 const char* ns_chat_markers = "urn:xmpp:chat-markers:0";
+// XEP-0334: Message Processing Hints
+const char* ns_message_processing_hints = "urn:xmpp:hints";
 // XEP-0352: Client State Indication
 const char* ns_csi = "urn:xmpp:csi:0";
 // XEP-0363: HTTP File Upload
diff --git a/src/base/QXmppConstants_p.h b/src/base/QXmppConstants_p.h
index 86003970..ba39ee05 100644
--- a/src/base/QXmppConstants_p.h
+++ b/src/base/QXmppConstants_p.h
@@ -145,6 +145,8 @@ extern const char* ns_mam;
 extern const char* ns_idle;
 // XEP-0333: Char Markers
 extern const char* ns_chat_markers;
+// XEP-0334: Message Processing Hints:
+extern const char* ns_message_processing_hints;
 // XEP-0352: Client State Indication
 extern const char* ns_csi;
 // XEP-0363: HTTP File Upload
diff --git a/src/base/QXmppMessage.cpp b/src/base/QXmppMessage.cpp
index 54ef4cd6..9806edf0 100644
--- a/src/base/QXmppMessage.cpp
+++ b/src/base/QXmppMessage.cpp
@@ -64,6 +64,13 @@ static const QStringList ENCRYPTION_NAMESPACES = {
     ns_omemo
 };
 
+static const QStringList HINT_TYPES = {
+    QStringLiteral("no-permanent-store"),
+    QStringLiteral("no-store"),
+    QStringLiteral("no-copy"),
+    QStringLiteral("store")
+};
+
 static const QStringList ENCRYPTION_NAMES = {
     QString(),
     QString(),
@@ -121,6 +128,9 @@ public:
     // XEP-0308: Last Message Correction
     QString replaceId;
 
+    // XEP-0334: Message Processing Hints
+    quint8 hints;
+
     // XEP-0367: Message Attaching
     QString attachId;
 
@@ -161,6 +171,8 @@ QXmppMessage::QXmppMessage(const QString& from, const QString& to, const
     d->marker = NoMarker;
 
     d->privatemsg = false;
+
+    d->hints = 0;
 }
 
 /// Constructs a copy of \a other.
@@ -546,6 +558,38 @@ void QXmppMessage::setReplaceId(const QString &replaceId)
     d->replaceId = replaceId;
 }
 
+/// Returns true if the message contains the hint passed, as defined in
+/// XEP-0334: Message Processing Hints
+
+bool QXmppMessage::hasHint(const Hint hint) const
+{
+    return d->hints & hint;
+}
+
+/// Adds a hint to the message, as defined in XEP-0334: Message Processing
+/// Hints
+
+void QXmppMessage::addHint(const Hint hint)
+{
+    d->hints |= hint;
+}
+
+/// Removes a hint from the message, as defined in XEP-0334: Message Processing
+/// Hints
+
+void QXmppMessage::removeHint(const Hint hint)
+{
+    d->hints &= ~hint;
+}
+
+/// Removes all hints from the message, as defined in XEP-0334: Message
+/// Processing Hints
+
+void QXmppMessage::removeAllHints()
+{
+    d->hints = 0;
+}
+
 /// Returns the message id this message is linked/attached to. See XEP-0367:
 /// Message Attaching for details.
 
@@ -848,6 +892,9 @@ void QXmppMessage::parse(const QDomElement &element)
             else {
                 extensions << QXmppElement(xElement);
             }
+        // XEP-0334: Message Processing Hints
+        } else if (xElement.namespaceURI() == ns_message_processing_hints && HINT_TYPES.contains(xElement.tagName())) {
+            addHint(Hint(1 << HINT_TYPES.indexOf(xElement.tagName())));
         // XEP-0367: Message Attaching
         } else if (xElement.tagName() == "attach-to" && xElement.namespaceURI() == ns_message_attaching) {
             d->attachId = xElement.attribute("id");
@@ -1000,6 +1047,15 @@ void QXmppMessage::toXml(QXmlStreamWriter *xmlWriter) const
         xmlWriter->writeEndElement();
     }
 
+    // XEP-0334: Message Processing Hints
+    for (quint8 i = 0; i < HINT_TYPES.size(); i++) {
+        if (hasHint(Hint(1 << i))) {
+            xmlWriter->writeStartElement(HINT_TYPES.at(i));
+            xmlWriter->writeAttribute("xmlns", ns_message_processing_hints);
+            xmlWriter->writeEndElement();
+        }
+    }
+
     // XEP-0367: Message Attaching
     if (!d->attachId.isEmpty()) {
         xmlWriter->writeStartElement("attach-to");
diff --git a/src/base/QXmppMessage.h b/src/base/QXmppMessage.h
index 69e2d451..9021f0cb 100644
--- a/src/base/QXmppMessage.h
+++ b/src/base/QXmppMessage.h
@@ -66,6 +66,14 @@ public:
         Acknowledged
     };
 
+    /// XEP-0334: Message Processing Hints
+    enum Hint {
+        NoPermanentStore = 1 << 0,  ///< Do not allow permanent storage
+        NoStore = 1 << 1,           ///< Do not store at all
+        NoCopy = 1 << 2,            ///< Do not copy the message
+        Store = 1 << 3              ///< Do store the message
+    };
+
     /// This enum describes different end-to-end encryption methods. These can
     /// be used to mark a message explicitly as encrypted with a specific
     /// algothim. See XEP-0380: Explicit Message Encryption for details.
@@ -152,6 +160,12 @@ public:
     QString replaceId() const;
     void setReplaceId(const QString&);
 
+    // XEP-0334: Message Processing Hints
+    bool hasHint(const Hint hint) const;
+    void addHint(const Hint hint);
+    void removeHint(const Hint hint);
+    void removeAllHints();
+
     // XEP-0367: Message Attaching
     QString attachId() const;
     void setAttachId(const QString&);