Add install reason why component is uninstalled

In details view uninstallable and installable components are listed. For
installable components a reason is shown why the component is installed.
Added similar kind of message for uninstallable components as well.

Task-number: QTIFW-2581
Change-Id: Idbf31200793a6c89a4ed4a6fc115f49889b5f9b5
Reviewed-by: Arttu Tarkiainen <arttu.tarkiainen@qt.io>

6 files changed, 119 insertions, 13 deletions

diff --git a/src/libs/installer/packagemanagercore.cpp b/src/libs/installer/packagemanagercore.cpp
index 918b01ad6..363609a92 100644
--- a/src/libs/installer/packagemanagercore.cpp
+++ b/src/libs/installer/packagemanagercore.cpp
@@ -2107,7 +2107,6 @@ QList<Component*> PackageManagerCore::orderedComponentsToInstall() const
 bool PackageManagerCore::calculateComponents(QString *displayString)
 {
     QString htmlOutput;
-    QString lastInstallReason;
     if (!calculateComponentsToUninstall() ||
             !calculateComponentsToInstall()) {
         htmlOutput.append(QString::fromLatin1("<h2><font color=\"red\">%1</font></h2><ul>")
@@ -2125,13 +2124,24 @@ bool PackageManagerCore::calculateComponents(QString *displayString)
 
     QList<Component*> componentsToRemove = componentsToUninstall();
     if (!componentsToRemove.isEmpty()) {
+        QMap<QString, QStringList> orderedUninstallReasons;
         htmlOutput.append(QString::fromLatin1("<h3>%1</h3><ul>").arg(tr("Components about to "
-            "be removed.")));
-        foreach (Component *component, componentsToRemove)
-            htmlOutput.append(QString::fromLatin1("<li> %1 </li>").arg(component->name()));
+            "be removed:")));
+        foreach (Component *component, componentsToRemove) {
+            const QString reason = uninstallReason(component);
+            QStringList value = orderedUninstallReasons.value(reason);
+            orderedUninstallReasons.insert(reason, value << component->name());
+        }
+        for (auto &reason : orderedUninstallReasons.keys()) {
+            htmlOutput.append(QString::fromLatin1("<h4>%1</h4><ul>").arg(reason));
+            foreach (const QString componentName, orderedUninstallReasons.value(reason))
+                htmlOutput.append(QString::fromLatin1("<li> %1 </li>").arg(componentName));
+            htmlOutput.append(QLatin1String("</ul>"));
+        }
         htmlOutput.append(QLatin1String("</ul>"));
     }
 
+    QString lastInstallReason;
     foreach (Component *component, orderedComponentsToInstall()) {
         const QString reason = installReason(component);
         if (lastInstallReason != reason) {
@@ -2201,6 +2211,22 @@ QString PackageManagerCore::installReason(Component *component) const
 }
 
 /*!
+    Returns the reason why \a component needs to be uninstalled:
+
+    \list
+        \li The component was scheduled for uninstallation.
+        \li The component was replaced by another component.
+        \li The component is virtual and its dependencies are uninstalled.
+        \li The components dependencies are uninstalled.
+        \li The components autodependencies are uninstalled.
+    \endlist
+*/
+QString PackageManagerCore::uninstallReason(Component *component) const
+{
+    return d->uninstallerCalculator()->uninstallReason(component);
+}
+
+/*!
     Returns a list of components that depend on \a _component. The list can be
     empty.
 
diff --git a/src/libs/installer/packagemanagercore.h b/src/libs/installer/packagemanagercore.h
index 012c57d58..523661797 100644
--- a/src/libs/installer/packagemanagercore.h
+++ b/src/libs/installer/packagemanagercore.h
@@ -240,6 +240,7 @@ public:
 
     QString componentsToInstallError() const;
     QString installReason(Component *component) const;
+    QString uninstallReason(Component *component) const;
 
     QList<Component*> dependees(const Component *component) const;
     QList<Component*> installDependants(const Component *component) const;
diff --git a/src/libs/installer/packagemanagercore_p.cpp b/src/libs/installer/packagemanagercore_p.cpp
index 4aaa27cfd..464a68109 100644
--- a/src/libs/installer/packagemanagercore_p.cpp
+++ b/src/libs/installer/packagemanagercore_p.cpp
@@ -2792,6 +2792,8 @@ void PackageManagerCorePrivate::calculateUninstallComponents()
         QPair<Component*, Component*> comp = componentsToReplace().value(component->name());
         if (comp.first) {
             if (comp.first->isSelectedForInstallation() || comp.first->updateRequested()) {
+                uninstallerCalculator()->insertUninstallReason(component,
+                    UninstallerCalculator::Replaced, comp.first->name());
                 selectedComponentsToUninstall.append(comp.second);
             }
         }
diff --git a/src/libs/installer/uninstallercalculator.cpp b/src/libs/installer/uninstallercalculator.cpp
index 7d5ce9e2a..a8c47e523 100644
--- a/src/libs/installer/uninstallercalculator.cpp
+++ b/src/libs/installer/uninstallercalculator.cpp
@@ -66,8 +66,10 @@ void UninstallerCalculator::appendComponentToUninstall(Component *component)
     QSet<Component *> dependees = QSet<Component *>(dependeesList.begin(),
         dependeesList.end()).subtract(m_componentsToUninstall);
 
-    foreach (Component *dependee, dependees)
+    foreach (Component *dependee, dependees) {
         appendComponentToUninstall(dependee);
+        insertUninstallReason(dependee, UninstallerCalculator::Dependent, component->name());
+    }
 
     m_componentsToUninstall.insert(component);
 }
@@ -119,6 +121,7 @@ void UninstallerCalculator::appendComponentsToUninstall(const QList<Component*>
             // A component requested auto uninstallation, keep it to resolve their dependencies as well.
             if (!autoDependencies.isEmpty()) {
                 autoDependOnList.append(component);
+                insertUninstallReason(component, UninstallerCalculator::AutoDependent, autoDependencies.join(QLatin1String(", ")));
                 component->setInstallAction(ComponentModelHelper::AutodependUninstallation);
             }
         }
@@ -130,6 +133,50 @@ void UninstallerCalculator::appendComponentsToUninstall(const QList<Component*>
         appendVirtualComponentsToUninstall();
 }
 
+void UninstallerCalculator::insertUninstallReason(Component *component, UninstallReasonType uninstallReason,
+                                                  const QString &referencedComponentName)
+{
+    // keep the first reason
+    if (m_toUninstallComponentIdReasonHash.contains(component->name()))
+        return;
+    m_toUninstallComponentIdReasonHash.insert(component->name(),
+        qMakePair(uninstallReason, referencedComponentName));
+}
+
+QString UninstallerCalculator::uninstallReason(Component *component) const
+{
+    UninstallerCalculator::UninstallReasonType reason = uninstallReasonType(component);
+    switch (reason) {
+        case Selected:
+            return QCoreApplication::translate("UninstallerCalculator",
+                "Deselected Components:");
+        case Replaced:
+            return QCoreApplication::translate("UninstallerCalculator", "Components replaced "
+                "by \"%1\":").arg(uninstallReasonReferencedComponent(component));
+        case VirtualDependent:
+            return QCoreApplication::translate("UninstallerCalculator",
+                "Removing virtual components without existing dependencies:");
+        case Dependent:
+            return QCoreApplication::translate("UninstallerCalculator", "Components "
+                "dependency \"%1\" removed:").arg(uninstallReasonReferencedComponent(component));
+        case AutoDependent:
+            return QCoreApplication::translate("UninstallerCalculator", "Components "
+                "autodependency \"%1\" removed:").arg(uninstallReasonReferencedComponent(component));
+    }
+    return QString();
+}
+
+UninstallerCalculator::UninstallReasonType UninstallerCalculator::uninstallReasonType(Component *c) const
+{
+    return m_toUninstallComponentIdReasonHash.value(c->name()).first;
+}
+
+QString UninstallerCalculator::uninstallReasonReferencedComponent(Component *component) const
+{
+    return m_toUninstallComponentIdReasonHash.value(component->name()).second;
+}
+
+
 void UninstallerCalculator::appendVirtualComponentsToUninstall()
 {
     QList<Component*> unneededVirtualList;
@@ -148,8 +195,10 @@ void UninstallerCalculator::appendVirtualComponentsToUninstall()
                     break;
                 }
             }
-            if (!required)
+            if (!required) {
                 unneededVirtualList.append(component);
+                insertUninstallReason(component, UninstallerCalculator::VirtualDependent);
+            }
         }
     }
 
diff --git a/src/libs/installer/uninstallercalculator.h b/src/libs/installer/uninstallercalculator.h
index fb7035d4e..c20616e93 100644
--- a/src/libs/installer/uninstallercalculator.h
+++ b/src/libs/installer/uninstallercalculator.h
@@ -43,11 +43,26 @@ class PackageManagerCore;
 class INSTALLER_EXPORT UninstallerCalculator
 {
 public:
+    enum UninstallReasonType
+    {
+        Selected,         // "Deselected Component(s)"
+        Replaced,         // "Component(s) replaced by other components"
+        VirtualDependent, // "No dependencies to virtual component"
+        Dependent,        // "Removed as dependency component is removed"
+        AutoDependent     // "Removed as autodependency component is removed"
+    };
+
     UninstallerCalculator(const QList<Component *> &installedComponents, PackageManagerCore *core);
 
     QSet<Component*> componentsToUninstall() const;
 
     void appendComponentsToUninstall(const QList<Component*> &components);
+    void insertUninstallReason(Component *component,
+                               UninstallReasonType installReasonType,
+                               const QString &referencedComponentName = QString());
+    QString uninstallReason(Component *component) const;
+    UninstallerCalculator::UninstallReasonType uninstallReasonType(Component *c) const;
+    QString uninstallReasonReferencedComponent(Component *component) const;
 
 private:
 
@@ -57,6 +72,7 @@ private:
     QList<Component *> m_installedComponents;
     QSet<Component *> m_componentsToUninstall;
     PackageManagerCore *m_core;
+    QHash<QString, QPair<UninstallReasonType, QString> > m_toUninstallComponentIdReasonHash;
 };
 
 }
diff --git a/tests/auto/installer/solver/tst_solver.cpp b/tests/auto/installer/solver/tst_solver.cpp
index 2f4e17855..5e499da2d 100644
--- a/tests/auto/installer/solver/tst_solver.cpp
+++ b/tests/auto/installer/solver/tst_solver.cpp
@@ -39,6 +39,9 @@
 using namespace QInstaller;
 
 typedef QMap<Component *, QStringList> ComponentToStringList;
+typedef QList<QPair<Component *, UninstallerCalculator::UninstallReasonType>> UninstallReasonList;
+
+Q_DECLARE_METATYPE(UninstallReasonList)
 
 class Data {
 public:
@@ -218,7 +221,6 @@ private slots:
                         << (QList<Component *>() << componentA)
                         << (QList<Component *>());
         }
-
     }
 
     void unresolvedDependencyVersion()
@@ -242,7 +244,9 @@ private slots:
         QTest::addColumn<QList<Component *> >("selectedToUninstall");
         QTest::addColumn<QList<Component *> >("installedComponents");
         QTest::addColumn<QSet<Component *> >("expectedResult");
+        QTest::addColumn<UninstallReasonList >("uninstallReasons");
 
+        UninstallReasonList uninstallReasonList;
         PackageManagerCore *core = new PackageManagerCore();
         core->setPackageManager();
         NamedComponent *componentA = new NamedComponent(core, QLatin1String("A"));
@@ -259,11 +263,15 @@ private slots:
         componentB->setInstalled();
         componentAB->setInstalled();
 
+        uninstallReasonList.append(qMakePair(componentAB, UninstallerCalculator::Selected));
+        uninstallReasonList.append(qMakePair(componentB, UninstallerCalculator::Dependent));
         QTest::newRow("Uninstaller resolved") << core
                     << (QList<Component *>() << componentAB)
                     << (QList<Component *>() << componentA << componentB)
-                    << (QSet<Component *>() << componentAB << componentB);
+                    << (QSet<Component *>() << componentAB << componentB)
+                    << (uninstallReasonList);
 
+        uninstallReasonList.clear();
         core = new PackageManagerCore();
         core->setPackageManager();
         NamedComponent *compA = new NamedComponent(core, QLatin1String("A"));
@@ -277,10 +285,13 @@ private slots:
         compA->setInstalled();
         compB->setInstalled();
 
+        uninstallReasonList.append(qMakePair(compA, UninstallerCalculator::Selected));
+        uninstallReasonList.append(qMakePair(compB, UninstallerCalculator::Dependent));
         QTest::newRow("Cascade dependencies") << core
                     << (QList<Component *>() << compA)
                     << (QList<Component *>() << compB)
-                    << (QSet<Component *>() << compA << compB);
+                    << (QSet<Component *>() << compA << compB)
+                    << (uninstallReasonList);
     }
 
     void resolveUninstaller()
@@ -289,17 +300,19 @@ private slots:
         QFETCH(QList<Component *> , selectedToUninstall);
         QFETCH(QList<Component *> , installedComponents);
         QFETCH(QSet<Component *> , expectedResult);
-
+        QFETCH(UninstallReasonList, uninstallReasons);
         UninstallerCalculator calc(installedComponents, core);
         calc.appendComponentsToUninstall(selectedToUninstall);
         QSet<Component *> result = calc.componentsToUninstall();
-
+        for (auto pair : uninstallReasons) {
+            UninstallerCalculator::UninstallReasonType type = calc.uninstallReasonType(pair.first);
+            QCOMPARE(pair.second, type);
+        }
         QCOMPARE(result.count(), expectedResult.count());
         QCOMPARE(result, expectedResult);
         delete core;
     }
 
-
     void checkComponent_data()
     {
         QTest::addColumn<QList<Component *> >("componentsToCheck");
@@ -342,7 +355,6 @@ private slots:
         QTest::newRow("AutoDepend and dependency")
                 << (QList<Component *>() << componentC << componentD << componentE)
                 << result;
-
     }
 
     void checkComponent()