[464535] Contribution to smart import mechanism

See https://wiki.eclipse.org/E4/UI/Smart_Import

Change-Id: I070e84c33191679d919fa22196546d05c5bfd618
Signed-off-by: Mickael Istria <mistria@redhat.com>

7 files changed, 392 insertions, 0 deletions

diff --git a/org.eclipse.m2e.importer/META-INF/MANIFEST.MF b/org.eclipse.m2e.importer/META-INF/MANIFEST.MF
new file mode 100644
index 00000000..6f58749d
--- /dev/null
+++ b/org.eclipse.m2e.importer/META-INF/MANIFEST.MF
@@ -0,0 +1,18 @@
+Manifest-Version: 1.0
+Bundle-ManifestVersion: 2
+Bundle-Name: %Bundle-Name
+Bundle-SymbolicName: org.eclipse.m2e.importer;singleton:=true
+Bundle-Version: 1.7.0.qualifier
+Bundle-Vendor: %Bundle-Vendor
+Bundle-Localization: plugin
+Require-Bundle: org.eclipse.e4.ui.importer,
+ org.eclipse.ui,
+ org.eclipse.core.runtime,
+ org.eclipse.core.resources,
+ org.eclipse.ui.ide,
+ org.eclipse.m2e.core;bundle-version="1.6.0",
+ org.eclipse.m2e.core.ui;bundle-version="1.6.0",
+ org.slf4j.api;bundle-version="1.6.2"
+Bundle-RequiredExecutionEnvironment: JavaSE-1.7
+Bundle-ActivationPolicy: lazy
+Bundle-Activator: org.eclipse.m2e.importer.internal.Activator
diff --git a/org.eclipse.m2e.importer/build.properties b/org.eclipse.m2e.importer/build.properties
new file mode 100644
index 00000000..6e6a38f7
--- /dev/null
+++ b/org.eclipse.m2e.importer/build.properties
@@ -0,0 +1,6 @@
+source.. = src/
+output.. = target/classes
+bin.includes = META-INF/,\
+               .,\
+               plugin.properties,\
+               plugin.xml
\ No newline at end of file
diff --git a/org.eclipse.m2e.importer/plugin.properties b/org.eclipse.m2e.importer/plugin.properties
new file mode 100644
index 00000000..e5b6534d
--- /dev/null
+++ b/org.eclipse.m2e.importer/plugin.properties
@@ -0,0 +1,2 @@
+Bundle-Vendor = Eclipse.org - m2e
+Bundle-Name = m2e extension for import framework
\ No newline at end of file
diff --git a/org.eclipse.m2e.importer/plugin.xml b/org.eclipse.m2e.importer/plugin.xml
new file mode 100644
index 00000000..d1d0b96e
--- /dev/null
+++ b/org.eclipse.m2e.importer/plugin.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<?eclipse version="3.4"?>
+<plugin>
+   <extension
+         point="org.eclipse.e4.ui.importer.projectConfigurators">
+      <projectConfigurator
+            class="org.eclipse.m2e.importer.internal.MavenProjectConfigurator"
+            label="Maven">
+         <activeWhen>
+            <hasFile
+                  path="pom.xml">
+            </hasFile>
+         </activeWhen>
+      </projectConfigurator>
+   </extension>
+</plugin>
diff --git a/org.eclipse.m2e.importer/pom.xml b/org.eclipse.m2e.importer/pom.xml
new file mode 100644
index 00000000..15d15df3
--- /dev/null
+++ b/org.eclipse.m2e.importer/pom.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>org.eclipse.m2e</groupId>
+    <artifactId>m2e-core</artifactId>
+    <version>1.7.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>org.eclipse.m2e.importer</artifactId>
+  <packaging>eclipse-plugin</packaging>
+
+  <name>Maven Integration for Eclipse Importer framework</name>
+
+</project>
diff --git a/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/Activator.java b/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/Activator.java
new file mode 100644
index 00000000..b6b87a45
--- /dev/null
+++ b/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/Activator.java
@@ -0,0 +1,64 @@
+/*******************************************************************************
+ * Copyright (c) 2014-2015 Red Hat Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+package org.eclipse.m2e.importer.internal;
+
+import org.eclipse.core.runtime.Status;
+import org.eclipse.ui.plugin.AbstractUIPlugin;
+import org.osgi.framework.BundleContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * The activator class controls the plug-in life cycle
+ */
+public class Activator extends AbstractUIPlugin {
+
+    // The plug-in ID
+    public static final String PLUGIN_ID = "org.eclipse.m2e.importer"; //$NON-NLS-1$
+
+    // The shared instance
+    private static Activator plugin;
+
+    /**
+     * The constructor
+     */
+    public Activator() {
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.eclipse.ui.plugin.AbstractUIPlugin#start(org.osgi.framework.
+     * BundleContext)
+     */
+    public void start(BundleContext context) throws Exception {
+        super.start(context);
+        plugin = this;
+    }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see org.eclipse.ui.plugin.AbstractUIPlugin#stop(org.osgi.framework.
+     * BundleContext)
+     */
+    public void stop(BundleContext context) throws Exception {
+        plugin = null;
+        super.stop(context);
+    }
+
+    /**
+     * Returns the shared instance
+     *
+     * @return the shared instance
+     */
+    public static Activator getDefault() {
+        return plugin;
+    }
+
+}
diff --git a/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/MavenProjectConfigurator.java b/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/MavenProjectConfigurator.java
new file mode 100644
index 00000000..df54c08a
--- /dev/null
+++ b/org.eclipse.m2e.importer/src/org/eclipse/m2e/importer/internal/MavenProjectConfigurator.java
@@ -0,0 +1,269 @@
+/*******************************************************************************
+ * Copyright (c) 2014-2015 Red Hat Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+package org.eclipse.m2e.importer.internal;
+
+import java.io.File;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+
+import org.eclipse.core.resources.IContainer;
+import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IFolder;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IProjectDescription;
+import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Path;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.jface.wizard.IWizard;
+import org.eclipse.m2e.core.MavenPlugin;
+import org.eclipse.m2e.core.internal.IMavenConstants;
+import org.eclipse.m2e.core.internal.lifecyclemapping.discovery.LifecycleMappingDiscoveryRequest;
+import org.eclipse.m2e.core.internal.project.ProjectConfigurationManager;
+import org.eclipse.m2e.core.project.IProjectConfigurationManager;
+import org.eclipse.m2e.core.project.LocalProjectScanner;
+import org.eclipse.m2e.core.project.MavenProjectInfo;
+import org.eclipse.m2e.core.project.MavenUpdateRequest;
+import org.eclipse.m2e.core.project.ResolverConfiguration;
+import org.eclipse.m2e.core.ui.internal.wizards.LifecycleMappingDiscoveryHelper;
+import org.eclipse.m2e.core.ui.internal.wizards.MappingDiscoveryJob;
+import org.eclipse.ui.internal.wizards.datatransfer.EasymportJob;
+import org.eclipse.ui.wizards.datatransfer.ProjectConfigurator;
+
+public class MavenProjectConfigurator implements ProjectConfigurator {
+
+    private static class CumulativeMappingDiscoveryJob extends MappingDiscoveryJob {
+        private static CumulativeMappingDiscoveryJob INSTANCE;
+        private Set<IProject> toProcess;
+        private boolean started;
+
+        public synchronized static CumulativeMappingDiscoveryJob getInstance() {
+            if (INSTANCE == null) {
+                INSTANCE = new CumulativeMappingDiscoveryJob();
+            }
+            return INSTANCE;
+        }
+
+        private CumulativeMappingDiscoveryJob() {
+            super(null);
+            this.toProcess = Collections.synchronizedSet(new HashSet<IProject>());
+        }
+        
+        public IStatus runInWorkspace(IProgressMonitor monitor) throws CoreException {
+            try {
+                // This makes job execution wait until the main Import job is completed
+                // So the mapping discovery happens as a next step, after projects are imported in workspace
+                getJobManager().join(EasymportJob.class, monitor);
+            } catch (InterruptedException ex) {
+                throw new CoreException(new Status(IStatus.WARNING,
+                        Activator.getDefault().getBundle().getSymbolicName(), ex.getMessage(), ex));
+            }
+            synchronized (this.toProcess) {
+                this.started = true;
+            }
+            // Detect and resolve Lifecycle Mapping issues
+            try {
+                LifecycleMappingDiscoveryRequest discoveryRequest = LifecycleMappingDiscoveryHelper
+                        .createLifecycleMappingDiscoveryRequest(toProcess, monitor);
+                if (discoveryRequest.isMappingComplete()) {
+                    return Status.OK_STATUS;
+                }
+                // Some errors were detected
+                discoverProposals(discoveryRequest, monitor);
+                openProposalWizard(toProcess, discoveryRequest);
+            } finally {
+                this.toProcess.clear();
+                this.started = false;
+            }
+            return Status.OK_STATUS;
+        }
+
+        public void addProjects(Collection<IProject> projects) {
+            synchronized (this.toProcess) {
+                if (this.started) {
+                    throw new IllegalStateException("Cannot add projects when processing is started");
+                }
+                if (projects != null) {
+                    this.toProcess.addAll(projects);
+                }
+            }
+        }
+
+    }
+
+    /**
+     * This singleton job will loop running on the background to update
+     * configuration of Maven projects as they're imported.
+     * 
+     * @author mistria
+     *
+     */
+    private static class UpdateMavenConfigurationJob extends Job {
+
+        private static UpdateMavenConfigurationJob INSTANCE;
+        private Set<IProject> toProcess;
+
+        public synchronized static UpdateMavenConfigurationJob getInstance() {
+            if (INSTANCE == null) {
+                INSTANCE = new UpdateMavenConfigurationJob();
+            }
+            return INSTANCE;
+        }
+
+        private UpdateMavenConfigurationJob() {
+            super("Update Maven projects configuration");
+            this.toProcess = Collections.synchronizedSet(new HashSet<IProject>());
+            this.setUser(true);
+        }
+
+        /**
+         * Rather than scheduling this job another time, requestors simply add
+         * to ask for being processed here. The job lifecycle will take care of
+         * processing it as best.
+         * 
+         * @param project
+         */
+        public void addProjectToProcess(IProject project) {
+            synchronized (this.toProcess) {
+                toProcess.add(project);
+            }
+        }
+
+        @Override
+        protected IStatus run(IProgressMonitor monitor) {
+            Set<IProject> toProcessNow = new HashSet<IProject>();
+            while (!monitor.isCanceled()) {
+                synchronized (this.toProcess) {
+                    if (this.toProcess.isEmpty()) {
+                        CumulativeMappingDiscoveryJob.getInstance().schedule();
+                        return Status.OK_STATUS;
+                    } else {
+                        toProcessNow.addAll(this.toProcess);
+                        this.toProcess.removeAll(toProcessNow);
+                    }
+                }
+                if (!toProcessNow.isEmpty()) {
+                    CumulativeMappingDiscoveryJob.getInstance().addProjects(toProcessNow);
+                    ProjectConfigurationManager configurationManager = (ProjectConfigurationManager) MavenPlugin
+                            .getProjectConfigurationManager();
+                    MavenUpdateRequest request = new MavenUpdateRequest(
+                            toProcessNow.toArray(new IProject[toProcessNow.size()]), false, false);
+                    Map<String, IStatus> updateStatus = configurationManager.updateProjectConfiguration(request, true,
+                            false, false, monitor);
+                }
+            }
+            return new Status(IStatus.CANCEL, Activator.getDefault().getBundle().getSymbolicName(),
+                    "Cancelled by user");
+        }
+
+    }
+
+    // TODO Uncomment @Override when following API got merged.
+    // this is commented in order to check it in build before API is available
+    // and avoid
+    // build failure because inteface doesn't declare the method (yet).
+    // @Override
+    public Set<File> findConfigurableLocations(File root, IProgressMonitor monitor) {
+        LocalProjectScanner scanner = new LocalProjectScanner(
+                ResourcesPlugin.getWorkspace().getRoot().getLocation().toFile(), root.getAbsolutePath(), false,
+                MavenPlugin.getMavenModelManager());
+        try {
+            scanner.run(monitor);
+        } catch (Exception ex) {
+            Activator.getDefault().getLog().log(new Status(IStatus.ERROR, Activator.PLUGIN_ID, ex.getMessage(), ex));
+            return null;
+        }
+        Queue<MavenProjectInfo> projects = new LinkedList<MavenProjectInfo>();
+        projects.addAll(scanner.getProjects());
+        HashSet<File> res = new HashSet<File>();
+        while (!projects.isEmpty()) {
+            MavenProjectInfo projectInfo = projects.poll();
+            res.add(projectInfo.getPomFile().getParentFile());
+            projects.addAll(projectInfo.getProjects());
+        }
+        return res;
+    }
+
+    @Override
+    public boolean canConfigure(IProject project, Set<IPath> ignoredPaths, IProgressMonitor monitor) {
+        return shouldBeAnEclipseProject(project, monitor);
+    }
+
+    @Override
+    public IWizard getConfigurationWizard() {
+        // no need for a wizard, will just set up the m2e nature
+        return null;
+    }
+
+    @Override
+    public void configure(final IProject project, Set<IPath> excludedDirectories, final IProgressMonitor monitor) {
+        // copied from
+        // org.eclipse.m2e.core.ui.internal.actions.EnableNatureAction
+
+        final ResolverConfiguration configuration = new ResolverConfiguration();
+        configuration.setResolveWorkspaceProjects(true);
+        final IProjectConfigurationManager configurationManager = MavenPlugin.getProjectConfigurationManager();
+        try {
+            if (!project.hasNature(IMavenConstants.NATURE_ID)) {
+                IProjectDescription description = project.getDescription();
+                String[] prevNatures = description.getNatureIds();
+                String[] newNatures = new String[prevNatures.length + 1];
+                System.arraycopy(prevNatures, 0, newNatures, 1, prevNatures.length);
+                newNatures[0] = IMavenConstants.NATURE_ID;
+                description.setNatureIds(newNatures);
+                project.setDescription(description, monitor);
+            }
+            UpdateMavenConfigurationJob.getInstance().addProjectToProcess(project);
+            if (UpdateMavenConfigurationJob.getInstance().getState() == Job.NONE) {
+                UpdateMavenConfigurationJob.getInstance().schedule();
+            }
+        } catch (Exception ex) {
+            Activator.getDefault().getLog().log(new Status(IStatus.ERROR, Activator.PLUGIN_ID, ex.getMessage(), ex));
+        }
+    }
+
+    @Override
+    public boolean shouldBeAnEclipseProject(IContainer container, IProgressMonitor monitor) {
+        IFile pomFile = container.getFile(new Path(IMavenConstants.POM_FILE_NAME));
+        return pomFile.exists();
+        // debated on m2e-dev:
+        // https://dev.eclipse.org/mhonarc/lists/m2e-dev/msg01852.html
+        // if (!pomFile.exists()) {
+        // return false;
+        // }
+        // try {
+        // Model pomModel =
+        // MavenPlugin.getMavenModelManager().readMavenModel(pomFile);
+        // return !pomModel.getPackaging().equals("pom"); // TODO find symbol
+        // for "pom"
+        // } catch (CoreException ex) {
+        // Activator.log(IStatus.ERROR, "Could not parse pom file " +
+        // pomFile.getLocation(), ex);
+        // return false;
+        // }
+    }
+
+    @Override
+    public Set<IFolder> getDirectoriesToIgnore(IProject project, IProgressMonitor monitor) {
+        Set<IFolder> res = new HashSet<IFolder>();
+        // TODO: get these values from pom/project config
+        res.add(project.getFolder("src"));
+        res.add(project.getFolder("target"));
+        return res;
+    }
+
+}