Autocomplete usernames based on most frequent in database

* Fixes #3126
* Limit autocompletion to the top ten used usernames
- Load common usernames when database is opened
- Transition from QLineEdit to QComboBox for usernames
- Dropdown menu of the combobox lets user choose a common username
- Common usernames are autocompleted via inline completion
- Common usernames are sorted by frequency (first) and name (second)

13 files changed, 134 insertions, 10 deletions

diff --git a/src/core/Config.cpp b/src/core/Config.cpp
index c9009236a..caf41c5d9 100644
--- a/src/core/Config.cpp
+++ b/src/core/Config.cpp
@@ -179,7 +179,6 @@ void Config::init(const QString& fileName)
     m_defaults.insert("SearchLimitGroup", false);
     m_defaults.insert("MinimizeOnCopy", false);
     m_defaults.insert("MinimizeOnOpenUrl", false);
-    m_defaults.insert("UseGroupIconOnEntryCreation", false);
     m_defaults.insert("AutoTypeEntryTitleMatch", true);
     m_defaults.insert("AutoTypeEntryURLMatch", true);
     m_defaults.insert("AutoTypeDelay", 25);
diff --git a/src/core/Database.cpp b/src/core/Database.cpp
index 571406059..6e69af5b0 100644
--- a/src/core/Database.cpp
+++ b/src/core/Database.cpp
@@ -54,6 +54,7 @@ Database::Database()
 
     connect(m_metadata, SIGNAL(metadataModified()), this, SLOT(markAsModified()));
     connect(m_timer, SIGNAL(timeout()), SIGNAL(databaseModified()));
+    connect(this, SIGNAL(databaseSaved()), SLOT(updateCommonUsernames()));
 
     m_modified = false;
     m_emitModified = true;
@@ -149,6 +150,8 @@ bool Database::open(const QString& filePath, QSharedPointer<const CompositeKey>
     setFilePath(filePath);
     dbFile.close();
 
+    updateCommonUsernames();
+
     setInitialized(ok);
     markAsClean();
 
@@ -525,6 +528,17 @@ void Database::addDeletedObject(const QUuid& uuid)
     addDeletedObject(delObj);
 }
 
+QList<QString> Database::commonUsernames()
+{
+    return m_commonUsernames;
+}
+
+void Database::updateCommonUsernames(int topN)
+{
+    m_commonUsernames.clear();
+    m_commonUsernames.append(rootGroup()->usernamesRecursive(topN));
+}
+
 const QUuid& Database::cipher() const
 {
     return m_data.cipher;
diff --git a/src/core/Database.h b/src/core/Database.h
index 09602f764..86d90c6a7 100644
--- a/src/core/Database.h
+++ b/src/core/Database.h
@@ -106,6 +106,8 @@ public:
     bool containsDeletedObject(const DeletedObject& uuid) const;
     void setDeletedObjects(const QList<DeletedObject>& delObjs);
 
+    QList<QString> commonUsernames();
+
     bool hasKey() const;
     QSharedPointer<const CompositeKey> key() const;
     bool setKey(const QSharedPointer<const CompositeKey>& key,
@@ -131,6 +133,7 @@ public:
 public slots:
     void markAsModified();
     void markAsClean();
+    void updateCommonUsernames(int topN = 10);
 
 signals:
     void filePathChanged(const QString& oldPath, const QString& newPath);
@@ -184,6 +187,8 @@ private:
     bool m_modified = false;
     bool m_emitModified;
 
+    QList<QString> m_commonUsernames;
+
     QUuid m_uuid;
     static QHash<QUuid, QPointer<Database>> s_uuidMap;
     static QHash<QString, QPointer<Database>> s_filePathMap;
diff --git a/src/core/Entry.cpp b/src/core/Entry.cpp
index 2ad73b055..c1f6286d4 100644
--- a/src/core/Entry.cpp
+++ b/src/core/Entry.cpp
@@ -341,6 +341,11 @@ bool Entry::isExpired() const
     return m_data.timeInfo.expires() && m_data.timeInfo.expiryTime() < Clock::currentDateTimeUtc();
 }
 
+bool Entry::isAttributeReference(const QString& key) const
+{
+    return m_attributes->isReference(key);
+}
+
 bool Entry::isAttributeReferenceOf(const QString& key, const QUuid& uuid) const
 {
     if (!m_attributes->isReference(key)) {
diff --git a/src/core/Entry.h b/src/core/Entry.h
index c5f59f2e3..45eb95ac5 100644
--- a/src/core/Entry.h
+++ b/src/core/Entry.h
@@ -111,6 +111,7 @@ public:
 
     bool hasTotp() const;
     bool isExpired() const;
+    bool isAttributeReference(const QString& key) const;
     bool isAttributeReferenceOf(const QString& key, const QUuid& uuid) const;
     void replaceReferencesWithValues(const Entry* other);
     bool hasReferences() const;
diff --git a/src/core/Group.cpp b/src/core/Group.cpp
index 84ad531be..9be878785 100644
--- a/src/core/Group.cpp
+++ b/src/core/Group.cpp
@@ -813,6 +813,42 @@ QSet<QUuid> Group::customIconsRecursive() const
     return result;
 }
 
+QList<QString> Group::usernamesRecursive(int topN) const
+{
+    // Collect all usernames and sort for easy counting
+    QHash<QString, int> countedUsernames;
+    for (const auto* entry : entriesRecursive()) {
+        const auto username = entry->username();
+        if (!username.isEmpty() && !entry->isAttributeReference(EntryAttributes::UserNameKey)) {
+            countedUsernames.insert(username, ++countedUsernames[username]);
+        }
+    }
+
+    // Sort username/frequency pairs by frequency and name
+    QList<QPair<QString, int>> sortedUsernames;
+    for (const auto& key : countedUsernames.keys()) {
+        sortedUsernames.append({key, countedUsernames[key]});
+    }
+
+    auto comparator = [](const QPair<QString, int>& arg1, const QPair<QString, int>& arg2) {
+        if (arg1.second == arg2.second) {
+            return arg1.first < arg2.first;
+        }
+        return arg1.second > arg2.second;
+    };
+
+    std::sort(sortedUsernames.begin(), sortedUsernames.end(), comparator);
+
+    // Take first topN usernames if set
+    QList<QString> usernames;
+    int actualUsernames = topN < 0 ? sortedUsernames.size() : std::min(topN, sortedUsernames.size());
+    for (int i = 0; i < actualUsernames; i++) {
+        usernames.append(sortedUsernames[i].first);
+    }
+
+    return usernames;
+}
+
 Group* Group::findGroupByUuid(const QUuid& uuid)
 {
     if (uuid.isNull()) {
diff --git a/src/core/Group.h b/src/core/Group.h
index 9fe65d69d..4b1204465 100644
--- a/src/core/Group.h
+++ b/src/core/Group.h
@@ -158,6 +158,7 @@ public:
     QList<const Group*> groupsRecursive(bool includeSelf) const;
     QList<Group*> groupsRecursive(bool includeSelf);
     QSet<QUuid> customIconsRecursive() const;
+    QList<QString> usernamesRecursive(int topN = -1) const;
 
     Group* clone(Entry::CloneFlags entryFlags = DefaultEntryCloneFlags,
                  CloneFlags groupFlags = DefaultCloneFlags) const;
diff --git a/src/gui/entry/EditEntryWidget.cpp b/src/gui/entry/EditEntryWidget.cpp
index b3dd6e3b4..523b8cdcd 100644
--- a/src/gui/entry/EditEntryWidget.cpp
+++ b/src/gui/entry/EditEntryWidget.cpp
@@ -85,6 +85,8 @@ EditEntryWidget::EditEntryWidget(QWidget* parent)
     , m_autoTypeAssocModel(new AutoTypeAssociationsModel(this))
     , m_autoTypeDefaultSequenceGroup(new QButtonGroup(this))
     , m_autoTypeWindowSequenceGroup(new QButtonGroup(this))
+    , m_usernameCompleter(new QCompleter(this))
+    , m_usernameCompleterModel(new QStringListModel(this))
 {
     setupMain();
     setupAdvanced();
@@ -129,6 +131,12 @@ void EditEntryWidget::setupMain()
     m_mainUi->setupUi(m_mainWidget);
     addPage(tr("Entry"), FilePath::instance()->icon("actions", "document-edit"), m_mainWidget);
 
+    m_mainUi->usernameComboBox->setEditable(true);
+    m_usernameCompleter->setCompletionMode(QCompleter::InlineCompletion);
+    m_usernameCompleter->setCaseSensitivity(Qt::CaseSensitive);
+    m_usernameCompleter->setModel(m_usernameCompleterModel);
+    m_mainUi->usernameComboBox->setCompleter(m_usernameCompleter);
+
     m_mainUi->togglePasswordButton->setIcon(filePath()->onOffIcon("actions", "password-show"));
     m_mainUi->togglePasswordGeneratorButton->setIcon(filePath()->icon("actions", "password-generator"));
 #ifdef WITH_XC_NETWORKING
@@ -273,7 +281,7 @@ void EditEntryWidget::setupEntryUpdate()
 {
     // Entry tab
     connect(m_mainUi->titleEdit, SIGNAL(textChanged(QString)), this, SLOT(setModified()));
-    connect(m_mainUi->usernameEdit, SIGNAL(textChanged(QString)), this, SLOT(setModified()));
+    connect(m_mainUi->usernameComboBox->lineEdit(), SIGNAL(textChanged(QString)), this, SLOT(setModified()));
     connect(m_mainUi->passwordEdit, SIGNAL(textChanged(QString)), this, SLOT(setModified()));
     connect(m_mainUi->passwordRepeatEdit, SIGNAL(textChanged(QString)), this, SLOT(setModified()));
     connect(m_mainUi->urlEdit, SIGNAL(textChanged(QString)), this, SLOT(setModified()));
@@ -707,7 +715,7 @@ void EditEntryWidget::setForms(Entry* entry, bool restore)
     m_customData->copyDataFrom(entry->customData());
 
     m_mainUi->titleEdit->setReadOnly(m_history);
-    m_mainUi->usernameEdit->setReadOnly(m_history);
+    m_mainUi->usernameComboBox->lineEdit()->setReadOnly(m_history);
     m_mainUi->urlEdit->setReadOnly(m_history);
     m_mainUi->passwordEdit->setReadOnly(m_history);
     m_mainUi->passwordRepeatEdit->setReadOnly(m_history);
@@ -742,7 +750,7 @@ void EditEntryWidget::setForms(Entry* entry, bool restore)
     m_historyWidget->setEnabled(!m_history);
 
     m_mainUi->titleEdit->setText(entry->title());
-    m_mainUi->usernameEdit->setText(entry->username());
+    m_mainUi->usernameComboBox->lineEdit()->setText(entry->username());
     m_mainUi->urlEdit->setText(entry->url());
     m_mainUi->passwordEdit->setText(entry->password());
     m_mainUi->passwordRepeatEdit->setText(entry->password());
@@ -751,6 +759,13 @@ void EditEntryWidget::setForms(Entry* entry, bool restore)
     m_mainUi->expirePresets->setEnabled(!m_history);
     m_mainUi->togglePasswordButton->setChecked(config()->get("security/passwordscleartext").toBool());
 
+    QList<QString> commonUsernames = m_db->commonUsernames();
+    m_usernameCompleterModel->setStringList(commonUsernames);
+    QString usernameToRestore = m_mainUi->usernameComboBox->lineEdit()->text();
+    m_mainUi->usernameComboBox->clear();
+    m_mainUi->usernameComboBox->addItems(commonUsernames);
+    m_mainUi->usernameComboBox->lineEdit()->setText(usernameToRestore);
+
     m_mainUi->notesEdit->setPlainText(entry->notes());
 
     m_advancedUi->attachmentsWidget->setEntryAttachments(entry->attachments());
@@ -910,7 +925,7 @@ void EditEntryWidget::updateEntryData(Entry* entry) const
     entry->attachments()->copyDataFrom(m_advancedUi->attachmentsWidget->entryAttachments());
     entry->customData()->copyDataFrom(m_customData.data());
     entry->setTitle(m_mainUi->titleEdit->text().replace(newLineRegex, " "));
-    entry->setUsername(m_mainUi->usernameEdit->text().replace(newLineRegex, " "));
+    entry->setUsername(m_mainUi->usernameComboBox->lineEdit()->text().replace(newLineRegex, " "));
     entry->setUrl(m_mainUi->urlEdit->text().replace(newLineRegex, " "));
     entry->setPassword(m_mainUi->passwordEdit->text());
     entry->setExpires(m_mainUi->expireCheck->isChecked());
diff --git a/src/gui/entry/EditEntryWidget.h b/src/gui/entry/EditEntryWidget.h
index aea3c894b..dd7bf8c07 100644
--- a/src/gui/entry/EditEntryWidget.h
+++ b/src/gui/entry/EditEntryWidget.h
@@ -20,6 +20,7 @@
 #define KEEPASSX_EDITENTRYWIDGET_H
 
 #include <QButtonGroup>
+#include <QCompleter>
 #include <QModelIndex>
 #include <QPointer>
 #include <QScopedPointer>
@@ -175,6 +176,8 @@ private:
     AutoTypeAssociationsModel* const m_autoTypeAssocModel;
     QButtonGroup* const m_autoTypeDefaultSequenceGroup;
     QButtonGroup* const m_autoTypeWindowSequenceGroup;
+    QCompleter* const m_usernameCompleter;
+    QStringListModel* const m_usernameCompleterModel;
 
     Q_DISABLE_COPY(EditEntryWidget)
 };
diff --git a/src/gui/entry/EditEntryWidgetMain.ui b/src/gui/entry/EditEntryWidgetMain.ui
index 3e759fec7..5ed534dc2 100644
--- a/src/gui/entry/EditEntryWidgetMain.ui
+++ b/src/gui/entry/EditEntryWidgetMain.ui
@@ -164,7 +164,7 @@
     <widget class="QLineEdit" name="titleEdit"/>
    </item>
    <item row="1" column="1">
-    <widget class="QLineEdit" name="usernameEdit"/>
+    <widget class="QComboBox" name="usernameComboBox"/>
    </item>
    <item row="7" column="0" alignment="Qt::AlignRight">
     <widget class="QCheckBox" name="expireCheck">
@@ -191,7 +191,7 @@
  </customwidgets>
  <tabstops>
   <tabstop>titleEdit</tabstop>
-  <tabstop>usernameEdit</tabstop>
+  <tabstop>usernameComboBox</tabstop>
   <tabstop>passwordEdit</tabstop>
   <tabstop>passwordRepeatEdit</tabstop>
   <tabstop>togglePasswordButton</tabstop>
diff --git a/tests/TestGroup.cpp b/tests/TestGroup.cpp
index f78cb96af..bd3d36081 100644
--- a/tests/TestGroup.cpp
+++ b/tests/TestGroup.cpp
@@ -1181,3 +1181,29 @@ void TestGroup::testApplyGroupIconRecursively()
     QVERIFY(subsubgroup->iconNumber() == iconForGroups);
     QVERIFY(subsubgroupEntry->iconNumber() == iconForEntries);
 }
+
+void TestGroup::testUsernamesRecursive()
+{
+    Database* database = new Database();
+
+    // Create a subgroup
+    Group* subgroup = new Group();
+    subgroup->setName("Subgroup");
+    subgroup->setParent(database->rootGroup());
+
+    // Generate entries in the root group and the subgroup
+    Entry* rootGroupEntry = database->rootGroup()->addEntryWithPath("Root group entry");
+    rootGroupEntry->setUsername("Name1");
+
+    Entry* subgroupEntry = subgroup->addEntryWithPath("Subgroup entry");
+    subgroupEntry->setUsername("Name2");
+
+    Entry* subgroupEntryReusingUsername = subgroup->addEntryWithPath("Another subgroup entry");
+    subgroupEntryReusingUsername->setUsername("Name2");
+
+    QList<QString> usernames = database->rootGroup()->usernamesRecursive();
+    QCOMPARE(usernames.size(), 2);
+    QVERIFY(usernames.contains("Name1"));
+    QVERIFY(usernames.contains("Name2"));
+    QVERIFY(usernames.indexOf("Name2") < usernames.indexOf("Name1"));
+}
diff --git a/tests/TestGroup.h b/tests/TestGroup.h
index 0ee735949..dbe5d6f4d 100644
--- a/tests/TestGroup.h
+++ b/tests/TestGroup.h
@@ -48,6 +48,7 @@ private slots:
     void testChildrenSort();
     void testHierarchy();
     void testApplyGroupIconRecursively();
+    void testUsernamesRecursive();
 };
 
 #endif // KEEPASSX_TESTGROUP_H
diff --git a/tests/gui/TestGui.cpp b/tests/gui/TestGui.cpp
index 3579d90f3..af5107288 100644
--- a/tests/gui/TestGui.cpp
+++ b/tests/gui/TestGui.cpp
@@ -507,7 +507,7 @@ void TestGui::testEditEntry()
     QVERIFY(okButton);
     QCOMPARE(m_dbWidget->currentMode(), DatabaseWidget::Mode::EditMode);
     titleEdit->setText("multiline\ntitle");
-    editEntryWidget->findChild<QLineEdit*>("usernameEdit")->setText("multiline\nusername");
+    editEntryWidget->findChild<QComboBox*>("usernameComboBox")->lineEdit()->setText("multiline\nusername");
     editEntryWidget->findChild<QLineEdit*>("passwordEdit")->setText("multiline\npassword");
     editEntryWidget->findChild<QLineEdit*>("passwordRepeatEdit")->setText("multiline\npassword");
     editEntryWidget->findChild<QLineEdit*>("urlEdit")->setText("multiline\nurl");
@@ -594,6 +594,10 @@ void TestGui::testAddEntry()
     auto* editEntryWidget = m_dbWidget->findChild<EditEntryWidget*>("editEntryWidget");
     auto* titleEdit = editEntryWidget->findChild<QLineEdit*>("titleEdit");
     QTest::keyClicks(titleEdit, "test");
+    auto* usernameComboBox = editEntryWidget->findChild<QComboBox*>("usernameComboBox");
+    QVERIFY(usernameComboBox);
+    QTest::mouseClick(usernameComboBox, Qt::LeftButton);
+    QTest::keyClicks(usernameComboBox, "AutocompletionUsername");
     auto* editEntryWidgetButtonBox = editEntryWidget->findChild<QDialogButtonBox*>("buttonBox");
     QTest::mouseClick(editEntryWidgetButtonBox->button(QDialogButtonBox::Ok), Qt::LeftButton);
 
@@ -602,17 +606,31 @@ void TestGui::testAddEntry()
     Entry* entry = entryView->entryFromIndex(item);
 
     QCOMPARE(entry->title(), QString("test"));
+    QCOMPARE(entry->username(), QString("AutocompletionUsername"));
     QCOMPARE(entry->historyItems().size(), 0);
 
+    m_db->updateCommonUsernames();
+
     // Add entry "something 2"
     QTest::mouseClick(entryNewWidget, Qt::LeftButton);
     QTest::keyClicks(titleEdit, "something 2");
+    QTest::mouseClick(usernameComboBox, Qt::LeftButton);
+    QTest::keyClicks(usernameComboBox, "Auto");
+    QTest::keyPress(usernameComboBox, Qt::Key_Right);
     auto* passwordEdit = editEntryWidget->findChild<QLineEdit*>("passwordEdit");
     auto* passwordRepeatEdit = editEntryWidget->findChild<QLineEdit*>("passwordRepeatEdit");
     QTest::keyClicks(passwordEdit, "something 2");
     QTest::keyClicks(passwordRepeatEdit, "something 2");
     QTest::mouseClick(editEntryWidgetButtonBox->button(QDialogButtonBox::Ok), Qt::LeftButton);
 
+    QCOMPARE(m_dbWidget->currentMode(), DatabaseWidget::Mode::ViewMode);
+    item = entryView->model()->index(1, 1);
+    entry = entryView->entryFromIndex(item);
+
+    QCOMPARE(entry->title(), QString("something 2"));
+    QCOMPARE(entry->username(), QString("AutocompletionUsername"));
+    QCOMPARE(entry->historyItems().size(), 0);
+
     // Add entry "something 5" but click cancel button (does NOT add entry)
     QTest::mouseClick(entryNewWidget, Qt::LeftButton);
     QTest::keyClicks(titleEdit, "something 5");
@@ -1063,8 +1081,8 @@ void TestGui::testEntryPlaceholders()
     auto* editEntryWidget = m_dbWidget->findChild<EditEntryWidget*>("editEntryWidget");
     auto* titleEdit = editEntryWidget->findChild<QLineEdit*>("titleEdit");
     QTest::keyClicks(titleEdit, "test");
-    QLineEdit* usernameEdit = editEntryWidget->findChild<QLineEdit*>("usernameEdit");
-    QTest::keyClicks(usernameEdit, "john");
+    QComboBox* usernameComboBox = editEntryWidget->findChild<QComboBox*>("usernameComboBox");
+    QTest::keyClicks(usernameComboBox, "john");
     QLineEdit* urlEdit = editEntryWidget->findChild<QLineEdit*>("urlEdit");
     QTest::keyClicks(urlEdit, "{TITLE}.{USERNAME}");
     auto* editEntryWidgetButtonBox = editEntryWidget->findChild<QDialogButtonBox*>("buttonBox");