Implement XEP-0447: Stateless file sharing: File sharing element (#448)

Implements parsing for the file sharing element from XEP-0447:
Stateless files sharing version 0.2.

https://xmpp.org/extensions/xep-0447.html

Co-authored-by: Jonah Brüchert <jbb@kaidan.im>

6 files changed, 253 insertions, 0 deletions

diff --git a/src/base/QXmppConstants.cpp b/src/base/QXmppConstants.cpp
index 86438f15..7f58911c 100644
--- a/src/base/QXmppConstants.cpp
+++ b/src/base/QXmppConstants.cpp
@@ -80,6 +80,8 @@ const char *ns_data = "jabber:x:data";
 // XEP-0095: Stream Initiation
 const char *ns_stream_initiation = "http://jabber.org/protocol/si";
 const char *ns_stream_initiation_file_transfer = "http://jabber.org/protocol/si/profile/file-transfer";
+// XEP-0103: URL Address Information
+const char *ns_url_data = "http://jabber.org/protocol/url-data";
 // XEP-0108: User Activity
 const char *ns_activity = "http://jabber.org/protocol/activity";
 // XEP-0115: Entity Capabilities
@@ -188,5 +190,7 @@ const char *ns_fallback_indication = "urn:xmpp:fallback:0";
 const char *ns_tm = "urn:xmpp:tm:1";
 // XEP-0446: File metadata element
 const char *ns_file_metadata = "urn:xmpp:file:metadata:0";
+// XEP-0447: Stateless file sharing
+const char *ns_sfs = "urn:xmpp:sfs:0";
 // XEP-0450: Automatic Trust Management (ATM)
 const char *ns_atm = "urn:xmpp:atm:1";
diff --git a/src/base/QXmppConstants_p.h b/src/base/QXmppConstants_p.h
index 4f8dd2ed..d040ed27 100644
--- a/src/base/QXmppConstants_p.h
+++ b/src/base/QXmppConstants_p.h
@@ -92,6 +92,8 @@ extern const char *ns_data;
 // XEP-0095: Stream Initiation
 extern const char *ns_stream_initiation;
 extern const char *ns_stream_initiation_file_transfer;
+// XEP-0103: URL Address Information
+extern const char *ns_url_data;
 // XEP-0108: User Activity
 extern const char *ns_activity;
 // XEP-0115: Entity Capabilities
@@ -200,6 +202,8 @@ extern const char *ns_fallback_indication;
 extern const char *ns_tm;
 // XEP-0446: File metadata element
 extern const char *ns_file_metadata;
+// XEP-0447: Stateless file sharing
+extern const char *ns_sfs;
 // XEP-0450: Automatic Trust Management (ATM)
 extern const char *ns_atm;
 
diff --git a/src/base/QXmppFileShare.cpp b/src/base/QXmppFileShare.cpp
new file mode 100644
index 00000000..8d73dbe5
--- /dev/null
+++ b/src/base/QXmppFileShare.cpp
@@ -0,0 +1,151 @@
+// SPDX-FileCopyrightText: 2022 Linus Jahn <lnj@kaidan.im>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "QXmppFileShare.h"
+
+#include "QXmppConstants_p.h"
+#include "QXmppFileMetadata.h"
+
+#include <optional>
+
+#include <QDomElement>
+#include <QUrl>
+#include <QXmlStreamWriter>
+
+using Disposition = QXmppFileShare::Disposition;
+
+static std::optional<Disposition> dispositionFromString(const QString &str)
+{
+    if (str == "inline") {
+        return Disposition::Inline;
+    }
+    if (str == "attachment") {
+        return Disposition::Attachment;
+    }
+    return {};
+}
+
+static QString dispositionToString(Disposition value)
+{
+    switch (value) {
+    case Disposition::Inline:
+        return QStringLiteral("inline");
+    case Disposition::Attachment:
+        return QStringLiteral("attachment");
+    }
+    Q_UNREACHABLE();
+}
+
+/// \cond
+class QXmppFileSharePrivate : public QSharedData
+{
+public:
+    QXmppFileMetadata metadata;
+    QVector<QUrl> httpSources;
+    QXmppFileShare::Disposition disposition = Disposition::Inline;
+};
+/// \endcond
+
+///
+/// \class QXmppFileSharePrivate
+///
+/// File sharing element from \xep{0447, Stateless file sharing}. Contains
+/// metadata and source URLs.
+///
+/// \note jinglepub references are currently missing
+///
+/// \since QXmpp 1.5
+///
+
+/// Default constructor
+QXmppFileShare::QXmppFileShare()
+    : d(new QXmppFileSharePrivate)
+{
+}
+
+QXmppFileShare::QXmppFileShare(const QXmppFileShare &) = default;
+QXmppFileShare::QXmppFileShare(QXmppFileShare &&) noexcept = default;
+QXmppFileShare::~QXmppFileShare() = default;
+QXmppFileShare &QXmppFileShare::operator=(const QXmppFileShare &) = default;
+QXmppFileShare &QXmppFileShare::operator=(QXmppFileShare &&) noexcept = default;
+
+/// Returns the disposition setting for this file.
+QXmppFileShare::Disposition QXmppFileShare::disposition() const
+{
+    return d->disposition;
+}
+
+/// Sets the disposition setting for this file.
+void QXmppFileShare::setDisposition(Disposition disp)
+{
+    d->disposition = disp;
+}
+
+const QXmppFileMetadata &QXmppFileShare::metadata() const
+{
+    return d->metadata;
+}
+
+void QXmppFileShare::setMetadata(const QXmppFileMetadata &metadata)
+{
+    d->metadata = metadata;
+}
+
+const QVector<QUrl> &QXmppFileShare::httpSources() const
+{
+    return d->httpSources;
+}
+
+void QXmppFileShare::setHttpSources(const QVector<QUrl> &newHttpSources)
+{
+    d->httpSources = newHttpSources;
+}
+
+/// \cond
+bool QXmppFileShare::parse(const QDomElement &el)
+{
+    if (el.tagName() == "file-sharing" && el.namespaceURI() == ns_sfs) {
+        // disposition
+        d->disposition = dispositionFromString(el.attribute("disposition"))
+                             .value_or(Disposition::Inline);
+
+        // file metadata
+        auto fileEl = el.firstChildElement("file");
+        d->metadata = QXmppFileMetadata();
+        if (!d->metadata.parse(fileEl)) {
+            return false;
+        }
+
+        // sources:
+        // expect that there's only one sources element with the correct namespace
+        auto sources = el.firstChildElement("sources");
+        for (auto urlEl = sources.firstChildElement("url-data");
+             !urlEl.isNull();
+             urlEl = urlEl.nextSiblingElement("url-data")) {
+            if (urlEl.namespaceURI() == "http://jabber.org/protocol/url-data") {
+                d->httpSources.append(QUrl(urlEl.attribute("target")));
+            }
+        }
+        return true;
+    }
+    return false;
+}
+
+void QXmppFileShare::toXml(QXmlStreamWriter *writer) const
+{
+    writer->writeStartElement("file-sharing");
+    writer->writeDefaultNamespace(ns_sfs);
+    writer->writeAttribute("disposition", dispositionToString(d->disposition));
+    d->metadata.toXml(writer);
+    writer->writeStartElement("sources");
+    for (const auto &source : d->httpSources) {
+        writer->writeStartElement("url-data");
+        writer->writeDefaultNamespace(ns_url_data);
+        writer->writeAttribute("target", source.toString());
+        writer->writeEndElement();
+    }
+    writer->writeEndElement();
+    writer->writeEndElement();
+}
+/// \endcond
diff --git a/src/base/QXmppFileShare.h b/src/base/QXmppFileShare.h
new file mode 100644
index 00000000..7d38df23
--- /dev/null
+++ b/src/base/QXmppFileShare.h
@@ -0,0 +1,52 @@
+// SPDX-FileCopyrightText: 2022 Linus Jahn <lnj@kaidan.im>
+//
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#ifndef QXMPPFILESHARE_H
+#define QXMPPFILESHARE_H
+
+#include "QXmppGlobal.h"
+
+#include <QSharedDataPointer>
+
+class QDomElement;
+class QUrl;
+class QXmlStreamWriter;
+class QXmppFileSharePrivate;
+class QXmppFileMetadata;
+
+class QXMPP_EXPORT QXmppFileShare
+{
+public:
+    enum Disposition {
+        Inline,
+        Attachment,
+    };
+
+    QXmppFileShare();
+    QXmppFileShare(const QXmppFileShare &);
+    QXmppFileShare(QXmppFileShare &&) noexcept;
+    ~QXmppFileShare();
+
+    QXmppFileShare &operator=(const QXmppFileShare &);
+    QXmppFileShare &operator=(QXmppFileShare &&) noexcept;
+
+    Disposition disposition() const;
+    void setDisposition(Disposition);
+
+    const QXmppFileMetadata &metadata() const;
+    void setMetadata(const QXmppFileMetadata &);
+
+    const QVector<QUrl> &httpSources() const;
+    void setHttpSources(const QVector<QUrl> &newHttpSources);
+
+    /// \cond
+    bool parse(const QDomElement &el);
+    void toXml(QXmlStreamWriter *writer) const;
+    /// \endcond
+
+private:
+    QSharedDataPointer<QXmppFileSharePrivate> d;
+};
+
+#endif  // QXMPPFILESHARE_H
diff --git a/src/base/QXmppMessage.cpp b/src/base/QXmppMessage.cpp
index 74e18149..f45789f0 100644
--- a/src/base/QXmppMessage.cpp
+++ b/src/base/QXmppMessage.cpp
@@ -9,6 +9,7 @@
 
 #include "QXmppBitsOfBinaryDataList.h"
 #include "QXmppConstants_p.h"
+#include "QXmppFileShare.h"
 #include "QXmppGlobal_p.h"
 #include "QXmppMixInvitation.h"
 #ifdef BUILD_OMEMO
@@ -151,6 +152,9 @@ public:
 
     // XEP-0434: Trust Messages (TM)
     std::optional<QXmppTrustMessageElement> trustMessageElement;
+
+    // XEP-0448: Encryption for stateless file sharing
+    QVector<QXmppFileShare> sharedFiles;
 };
 
 QXmppMessagePrivate::QXmppMessagePrivate()
@@ -1205,6 +1209,26 @@ void QXmppMessage::setTrustMessageElement(const std::optional<QXmppTrustMessageE
     d->trustMessageElement = trustMessageElement;
 }
 
+///
+/// Returns the via \xep{0447, Stateless file sharing} shared files attached to this message.
+///
+/// \since QXmpp 1.5
+///
+const QVector<QXmppFileShare> &QXmppMessage::sharedFiles() const
+{
+    return d->sharedFiles;
+}
+
+///
+/// Sets the via \xep{0447, Stateless file sharing} shared files attached to this message.
+///
+/// \since QXmpp 1.5
+///
+void QXmppMessage::setSharedFiles(const QVector<QXmppFileShare> &sharedFiles)
+{
+    d->sharedFiles = sharedFiles;
+}
+
 /// \cond
 void QXmppMessage::parse(const QDomElement &element)
 {
@@ -1489,6 +1513,14 @@ bool QXmppMessage::parseExtension(const QDomElement &element, QXmpp::SceMode sce
             d->trustMessageElement = trustMessageElement;
             return true;
         }
+        // XEP-0448: Stateless file sharing
+        if (checkElement(element, QStringLiteral("file-sharing"), ns_sfs)) {
+            QXmppFileShare share;
+            if (share.parse(element)) {
+                d->sharedFiles.push_back(std::move(share));
+            }
+            return true;
+        }
     }
     return false;
 }
@@ -1739,5 +1771,10 @@ void QXmppMessage::serializeExtensions(QXmlStreamWriter *writer, QXmpp::SceMode
         if (d->trustMessageElement) {
             d->trustMessageElement->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 43949118..a4d4fcbe 100644
--- a/src/base/QXmppMessage.h
+++ b/src/base/QXmppMessage.h
@@ -8,6 +8,7 @@
 #ifndef QXMPPMESSAGE_H
 #define QXMPPMESSAGE_H
 
+#include "QXmppFileShare.h"
 #include "QXmppStanza.h"
 
 #include <optional>
@@ -248,6 +249,10 @@ public:
     std::optional<QXmppTrustMessageElement> trustMessageElement() const;
     void setTrustMessageElement(const std::optional<QXmppTrustMessageElement> &trustMessageElement);
 
+    // XEP-0447: Stateless file sharing
+    const QVector<QXmppFileShare> &sharedFiles() const;
+    void setSharedFiles(const QVector<QXmppFileShare> &sharedFiles);
+
     /// \cond
 #ifdef BUILD_OMEMO
     // XEP-0384: OMEMO Encryption