[JENKINS-69339] badge icon for Management links (#6995)

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>
Co-authored-by: Basil Crow <me@basilcrow.com>
Co-authored-by: Daniel Beck <1831569+daniel-beck@users.noreply.github.com>
Co-authored-by: Tim Jacomb <timjacomb1@gmail.com>
Co-authored-by: Alexander Brandes <mc.cache@web.de>

core/src/main/java/hudson/diagnosis/OldDataMonitor.java

@@ -57,6 +57,7 @@ import java.util.concurrent.ConcurrentMap;
 import java.util.function.Predicate;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import jenkins.management.Badge;
 import jenkins.model.Jenkins;
 import org.jenkinsci.Symbol;
 import org.kohsuke.accmod.Restricted;
@@ -471,5 +472,14 @@ public class OldDataMonitor extends AdministrativeMonitor {
         public String getDisplayName() {
             return Messages.OldDataMonitor_DisplayName();
         }
+
+        @Override
+        public Badge getBadge() {
+            int size = get(Jenkins.get()).data.size();
+            if (size > 0) {
+                return new Badge(Integer.toString(size), Messages.OldDataMonitor_OldDataTooltip(), Badge.Severity.WARNING);
+            }
+            return null;
+        }
     }
 }

core/src/main/java/hudson/model/AdministrativeMonitor.java

@@ -70,7 +70,9 @@ import org.kohsuke.stapler.interceptor.RequirePOST;
  * {@code http://SERVER/jenkins/manage} page. This view should typically render
  * a DIV box with class='alert alert-danger' or class='alert alert-warning' with a human-readable text
  * inside it. It often also contains a link to a page that provides more details
- * about the problem.
+ * about the problem.<br>
+ * Additionally 2 numbers are shown in the Jenkins header of administrators, one with the number or active
+ * non-security relevant monitors and one with the number of active security relevant monitors.
  * </dd>
  * </dl>
  *

core/src/main/java/hudson/model/ManagementLink.java

@@ -34,6 +34,7 @@ import hudson.security.Permission;
 import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import jenkins.management.Badge;
 import jenkins.model.Jenkins;
 import org.jvnet.localizer.Localizable;
 import org.kohsuke.accmod.Restricted;
@@ -214,5 +215,15 @@ public abstract class ManagementLink implements ExtensionPoint, Action {
         }
     }
 
+    /**
+     * A {@link Badge} shown as overlay over the icon on "Manage Jenkins".
+     *
+     * @return badge or {@code null} if no badge should be shown.
+     * @since TODO
+     */
+    public @CheckForNull Badge getBadge() {
+        return null;
+    }
+
     private static final Logger LOGGER = Logger.getLogger(ManagementLink.class.getName());
 }

core/src/main/java/jenkins/management/Badge.java

@@ -0,0 +1,104 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2022, Markus Winter
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package jenkins.management;
+
+import edu.umd.cs.findbugs.annotations.NonNull;
+import hudson.diagnosis.OldDataMonitor;
+import hudson.model.AdministrativeMonitor;
+import hudson.model.ManagementLink;
+import java.util.Locale;
+
+/**
+ *  Definition of a badge that can be returned by a {@link ManagementLink} implementation.
+ *  The badge is shown as a small overlay over the corresponding icon on the {@code Manage Jenkins} page,
+ *  it can display additional information in a tooltip and change it's color depending on the severity.
+ *
+ *  <p>
+ *  A badge mainly serves as a fast feedback for the corresponding management page.
+ *  It could be used to just display some short status information or hint that some action can be taken.
+ *  For example the badge on {@code Manage Plugins} shows information about the number of available updates
+ *  and in its tooltip additionally how many updates contain incompatible changes or fix
+ *  security vulnerabilities. It also changes its color when there are security fixes available.
+ *
+ *  <p>
+ *  A badge might display the same information as an {@link AdministrativeMonitor}. While an {@link AdministrativeMonitor}
+ *  can be disabled, a badge will always be shown. E.g. the badge of {@link OldDataMonitor.ManagementLinkImpl} always shows the number of old data entries.
+ *
+ *  @since TODO
+ */
+public class Badge {
+
+    private final String text;
+    private final String tooltip;
+    private final Severity severity;
+
+    /**
+     * Create a new Badge
+     *
+     * @param text  The text to be shown in the badge.
+     *      Keep it short, ideally just a number. More than 6 or 7 characters do not look good. Avoid spaces as they will lead to line breaks.
+     *      as this might lead to line breaks.
+     * @param tooltip  The tooltip to show for the badge.
+     *      Do not include html tags.
+     * @param severity  The severity of the badge (danger, warning, info)
+     */
+    public Badge(@NonNull String text, @NonNull String tooltip, @NonNull Severity severity) {
+        this.text = text;
+        this.tooltip = tooltip;
+        this.severity = severity;
+    }
+
+    /**
+     * The text to be shown in the badge.
+     *
+     * @return badge text
+     */
+    public String getText() {
+        return text;
+    }
+
+    /**
+     * The tooltip of the badge.
+     *
+     * @return tooltip
+     */
+    public String getTooltip() {
+        return tooltip;
+    }
+
+    /**
+     * The severity of the badge.
+     * Influences the background color of the badge.
+     *
+     * @return severity as String
+     */
+    public String getSeverity() {
+        return severity.toString().toLowerCase(Locale.US);
+    }
+
+    public enum Severity {
+        DANGER, WARNING, INFO
+    }
+}

core/src/main/java/jenkins/management/PluginsLink.java

@@ -28,11 +28,11 @@ import edu.umd.cs.findbugs.annotations.NonNull;
 import hudson.Extension;
 import hudson.model.ManagementLink;
 import hudson.model.UpdateCenter;
+import hudson.model.UpdateSite.Plugin;
 import hudson.security.Permission;
+import java.util.List;
 import jenkins.model.Jenkins;
 import org.jenkinsci.Symbol;
-import org.kohsuke.accmod.Restricted;
-import org.kohsuke.accmod.restrictions.NoExternalUse;
 
 /**
  * @author <a href="mailto:nicolas.deloof@gmail.com">Nicolas De Loof</a>
@@ -72,13 +72,49 @@ public class PluginsLink extends ManagementLink {
         return Category.CONFIGURATION;
     }
 
-    @Restricted(NoExternalUse.class)
-    public int getUpdateCount() {
+    @Override
+    public Badge getBadge() {
         final UpdateCenter updateCenter = Jenkins.get().getUpdateCenter();
         if (!updateCenter.isSiteDataReady()) {
             // Do not display message during this page load, but possibly later.
-            return 0;
+            return null;
         }
-        return updateCenter.getUpdates().size();
+        List<Plugin> plugins = updateCenter.getUpdates();
+        int size = plugins.size();
+        if (size > 0) {
+            StringBuilder tooltip = new StringBuilder();
+            Badge.Severity severity = Badge.Severity.WARNING;
+            int securityFixSize = (int) plugins.stream().filter(plugin -> plugin.fixesSecurityVulnerabilities()).count();
+            int incompatibleSize = (int) plugins.stream().filter(plugin -> !plugin.isCompatibleWithInstalledVersion()).count();
+            if (size > 1) {
+                tooltip.append(Messages.PluginsLink_updatesAvailable(size));
+            } else {
+                tooltip.append(Messages.PluginsLink_updateAvailable());
+            }
+            switch (incompatibleSize) {
+                case 0:
+                    break;
+                case 1:
+                    tooltip.append("\n").append(Messages.PluginsLink_incompatibleUpdateAvailable());
+                    break;
+                default:
+                    tooltip.append("\n").append(Messages.PluginsLink_incompatibleUpdatesAvailable(incompatibleSize));
+                    break;
+            }
+            switch (securityFixSize) {
+                case 0:
+                    break;
+                case 1:
+                    tooltip.append("\n").append(Messages.PluginsLink_securityUpdateAvailable());
+                    severity = Badge.Severity.DANGER;
+                    break;
+                default:
+                    tooltip.append("\n").append(Messages.PluginsLink_securityUpdatesAvailable(securityFixSize));
+                    severity = Badge.Severity.DANGER;
+                    break;
+            }
+            return new Badge(Integer.toString(size), tooltip.toString(), severity);
+        }
+        return null;
     }
 }