Add how many rooms you have in common to the user detail dialog

Eventually this will be expanded into an actual list you can look
through, but this can at least give you an idea the
number of rooms this user shares with you. If the user doesn't share any
rooms with you (e.g. they left) then the label is hidden.

src/CMakeLists.txt

@@ -196,6 +196,8 @@ add_library(neochat STATIC
     models/messagecontentfiltermodel.h
     models/pinnedmessagemodel.cpp
     models/pinnedmessagemodel.h
+    models/commonroomsmodel.cpp
+    models/commonroomsmodel.h
 )
 
 set_source_files_properties(qml/OsmLocationPlugin.qml PROPERTIES

src/models/commonroomsmodel.cpp

@@ -0,0 +1,74 @@
+// SPDX-FileCopyrightText: 2025 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "commonroomsmodel.h"
+#include "jobs/neochatgetcommonroomsjob.h"
+
+#include <QGuiApplication>
+
+using namespace Quotient;
+
+CommonRoomsModel::CommonRoomsModel(QObject *parent)
+    : QAbstractListModel(parent)
+{
+}
+
+NeoChatConnection *CommonRoomsModel::connection() const
+{
+    return m_connection;
+}
+
+void CommonRoomsModel::setConnection(NeoChatConnection *connection)
+{
+    m_connection = connection;
+    Q_EMIT connectionChanged();
+    reload();
+}
+
+QString CommonRoomsModel::userId() const
+{
+    return m_userId;
+}
+
+void CommonRoomsModel::setUserId(const QString &userId)
+{
+    m_userId = userId;
+    Q_EMIT userIdChanged();
+    reload();
+}
+
+QVariant CommonRoomsModel::data(const QModelIndex &index, int roleName) const
+{
+    Q_UNUSED(index)
+    Q_UNUSED(roleName)
+    return {};
+}
+
+int CommonRoomsModel::rowCount(const QModelIndex &parent) const
+{
+    Q_UNUSED(parent)
+    return m_commonRooms.size();
+}
+
+void CommonRoomsModel::reload()
+{
+    if (!m_connection || m_userId.isEmpty()) {
+        return;
+    }
+
+    if (!m_connection->canCheckMutualRooms()) {
+        return;
+    }
+
+    m_connection->callApi<NeochatGetCommonRoomsJob>(m_userId).then([this](const auto job) {
+        const auto &replyData = job->jsonData();
+        beginResetModel();
+        for (const auto &roomId : replyData[u"joined"_s].toArray()) {
+            m_commonRooms.push_back(roomId.toString());
+        }
+        endResetModel();
+        Q_EMIT countChanged();
+    });
+}
+
+#include "moc_commonroomsmodel.cpp"

src/models/commonroomsmodel.h

@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: 2025 Joshua Goins <josh@redstrate.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <QAbstractListModel>
+#include <QQmlEngine>
+
+#include "neochatconnection.h"
+#include "neochatroom.h"
+
+#include <Quotient/events/roommessageevent.h>
+#include <Quotient/roommember.h>
+
+/**
+ * @brief Model to show the common or mutual rooms between you and another user.
+ */
+class CommonRoomsModel : public QAbstractListModel
+{
+    Q_OBJECT
+    QML_ELEMENT
+    Q_PROPERTY(NeoChatConnection *connection WRITE setConnection READ connection NOTIFY connectionChanged REQUIRED)
+    Q_PROPERTY(QString userId WRITE setUserId READ userId NOTIFY userIdChanged REQUIRED)
+    Q_PROPERTY(int count READ rowCount NOTIFY countChanged)
+
+public:
+    enum Roles {
+        TextRole = Qt::DisplayRole,
+        LongitudeRole,
+        LatitudeRole,
+        AssetRole,
+        AuthorRole,
+    };
+    Q_ENUM(Roles)
+
+    explicit CommonRoomsModel(QObject *parent = nullptr);
+
+    [[nodiscard]] NeoChatConnection *connection() const;
+    void setConnection(NeoChatConnection *connection);
+
+    [[nodiscard]] QString userId() const;
+    void setUserId(const QString &userId);
+
+    [[nodiscard]] QVariant data(const QModelIndex &index, int roleName) const override;
+    [[nodiscard]] Q_INVOKABLE int rowCount(const QModelIndex &parent = {}) const override;
+
+Q_SIGNALS:
+    void connectionChanged();
+    void userIdChanged();
+    void countChanged();
+
+private:
+    void reload();
+
+    QPointer<NeoChatConnection> m_connection;
+    QString m_userId;
+    QList<QString> m_commonRooms;
+};

src/qml/UserDetailDialog.qml

@@ -56,6 +56,8 @@ Kirigami.Dialog {
             ColumnLayout {
                 Layout.fillWidth: true
 
+                spacing: 0
+
                 Kirigami.Heading {
                     level: 1
                     Layout.fillWidth: true
@@ -71,6 +73,19 @@ Kirigami.Dialog {
                     textFormat: TextEdit.PlainText
                     text: root.user.id
                 }
+
+                QQC2.Label {
+                    property CommonRoomsModel model: CommonRoomsModel {
+                        connection: root.connection
+                        userId: root.user.id
+                    }
+
+                    text: i18ncp("@info", "One mutual room", "%1 mutual rooms", model.count)
+                    color: Kirigami.Theme.disabledTextColor
+                    visible: model.count > 0
+
+                    Layout.topMargin: Kirigami.Units.smallSpacing
+                }
             }
             QQC2.AbstractButton {
                 Layout.minimumHeight: avatar.height * 0.75