/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.netbeans.modules.junit;

import org.netbeans.modules.junit.api.JUnitTestUtil;
import com.sun.source.tree.Tree;
import com.sun.source.util.TreePath;
import java.awt.EventQueue;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.lang.model.element.Element;
import org.netbeans.api.java.classpath.ClassPath;
import org.netbeans.api.java.project.JavaProjectConstants;
import org.netbeans.api.java.queries.UnitTestForSourceQuery;
import org.netbeans.api.java.source.CancellableTask;
import org.netbeans.api.java.source.CompilationController;
import org.netbeans.api.java.source.JavaSource.Phase;
import org.netbeans.api.java.source.TreeUtilities;
import org.netbeans.api.project.FileOwnerQuery;
import org.netbeans.api.project.Project;
import org.netbeans.api.project.ProjectUtils;
import org.netbeans.api.project.SourceGroup;
import org.netbeans.spi.gototest.TestLocator;
import org.netbeans.modules.junit.plugin.JUnitPlugin;
//import org.netbeans.modules.junit.plugin.JUnitPlugin.Location;
import org.netbeans.modules.gsf.testrunner.plugin.CommonPlugin.Location;
import org.netbeans.spi.java.classpath.support.ClassPathSupport;
import org.openide.filesystems.FileObject;
import org.openide.util.NbBundle;
import org.openide.util.RequestProcessor;

/**
 * Jumps to the opposite class or method.
 * If the cursor is currently in a source method, this action will jump to the
 * corresponding test method and vice versa. If the cursor is currently in a
 * source class but not in any method, this action will switch to the beginning
 * of the corresponding class.
 *
 * @see  OpenTestAction
 * @author  Marian Petras
 */
@SuppressWarnings("serial")
@org.openide.util.lookup.ServiceProvider(service=org.netbeans.spi.gototest.TestLocator.class)
public final class GoToOppositeAction implements TestLocator {
    
    public GoToOppositeAction() {
    }
    

    public boolean asynchronous() {
        return true;
    }

    public LocationResult findOpposite(FileObject fileObj, int caretOffset) {
        throw new UnsupportedOperationException("JUnit's GoToOppositeAction is asynchronous");
    }
        
    public void findOpposite(FileObject fileObj, int caretOffset, LocationListener callback) {
        boolean isJavaFile = false;
        ClassPath srcCP;
        FileObject fileObjRoot;
        Project project;
        boolean sourceToTest = true;
        
        if ((fileObj == null)
          || !fileObj.isFolder() && !(isJavaFile = JUnitTestUtil.isJavaFile(fileObj))
          || ((srcCP = ClassPath.getClassPath(fileObj, ClassPath.SOURCE)) == null)
          || ((fileObjRoot = srcCP.findOwnerRoot(fileObj)) == null)
          || ((project = FileOwnerQuery.getOwner(fileObjRoot)) == null)
          || (UnitTestForSourceQuery.findUnitTests(fileObjRoot).length == 0)
              && !(sourceToTest = false)         //side effect - assignment
              && (!isJavaFile || (UnitTestForSourceQuery.findSources(fileObjRoot).length == 0))) {
            callback.foundLocation(fileObj, new LocationResult(null));
            return;
        }
        
        JUnitPlugin plugin = JUnitTestUtil.getPluginForProject(project);
        assert plugin != null;
        
        SourceGroup[] srcGroups;
        FileObject[] srcRoots;
        srcGroups = ProjectUtils.getSources(project)
                    .getSourceGroups(JavaProjectConstants.SOURCES_TYPE_JAVA);
        srcRoots = new FileObject[srcGroups.length];
        for (int i = 0; i < srcGroups.length; i++) {
            srcRoots[i] = srcGroups[i].getRootFolder();
        }
        ClassPath srcClassPath = ClassPathSupport.createClassPath(srcRoots);

        RequestProcessor requestProcessor = new RequestProcessor(GoToOppositeAction.class.getName(), 1);
	JUnitPlugin pluginIT = JUnitTestUtil.getITPluginForProject(project);
        assert pluginIT != null;
	requestProcessor.post(
                new ActionImpl(plugin, pluginIT,
                               callback,
                               new Location(fileObj),
                               sourceToTest,
                               srcClassPath));
    }
    
    /**
     * Determines an element at the current cursor position.
     */
    private class ElementFinder implements CancellableTask<CompilationController> {
        
        /** */
        private final int caretPosition;
        /** */
        private volatile boolean cancelled;
        /** */
        private Element element = null;
        
        /**
         */
        private ElementFinder(int caretPosition) {
            this.caretPosition = caretPosition;
        }
    
        /**
         */
        public void run(CompilationController controller) throws IOException {
            controller.toPhase(Phase.RESOLVED);     //cursor position needed
            if (cancelled) {
                return;
            }

            TreePath treePath = controller.getTreeUtilities()
                                          .pathFor(caretPosition);
            if (treePath != null) {
                if (cancelled) {
                    return;
                }
                
                TreePath parent = treePath.getParentPath();
                while (parent != null) {
                    Tree.Kind parentKind = parent.getLeaf().getKind();
                    if ((TreeUtilities.CLASS_TREE_KINDS.contains(parentKind))
                            || (parentKind == Tree.Kind.COMPILATION_UNIT)) {
                        break;
                    }
                    treePath = parent;
                    parent = treePath.getParentPath();
                }

            }

            if (treePath != null) {
                if (cancelled) {
                    return;
                }

                try {
                    element = controller.getTrees().getElement(treePath);
                } catch (IllegalArgumentException ex) {
                    Logger.getLogger("global").log(Level.WARNING, null, ex);
                }
            }
        }
        
        /**
         */
        public void cancel() {
            cancelled = true;
        }
        
        /**
         */
        Element getElement() {
            return element;
        }

    }
    
    /**
     * 
     */
    private class ActionImpl implements Runnable {
        
        private final JUnitPlugin plugin;
        private final JUnitPlugin pluginIT;
        private final Location currLocation;
        private final boolean sourceToTest;
        private final ClassPath srcClassPath;
        private final LocationListener callback;
        
        private Location oppoLocation;
	private Location oppoLocationIT;
        
        ActionImpl(JUnitPlugin plugin,
                   JUnitPlugin pluginIT,
                   LocationListener callback,
                   Location currLocation,
                   boolean sourceToTest,
                   ClassPath srcClassPath) {
            this.plugin = plugin;
            this.pluginIT = pluginIT;
            this.currLocation = currLocation;
            this.sourceToTest = sourceToTest;
            this.srcClassPath = srcClassPath;
            this.callback = callback;
        }
        
        public void run() {
            findOppositeLocation();
            if (oppoLocation != null || oppoLocationIT != null) {
                goToOppositeLocation();
            } else if (sourceToTest) {
                displayNoOppositeLocationFound();
            }
        }
        
        /**
         */
        private void findOppositeLocation() {
            oppoLocation = sourceToTest
                  ? JUnitPluginTrampoline.DEFAULT.getTestLocation(plugin,
                                                                  currLocation)
                  : JUnitPluginTrampoline.DEFAULT.getTestedLocation(plugin,
                                                                  currLocation);
	    oppoLocationIT = sourceToTest
		    ? JUnitPluginTrampoline.DEFAULT.getTestLocation(pluginIT,
		    currLocation)
		    : JUnitPluginTrampoline.DEFAULT.getTestedLocation(pluginIT,
		    currLocation);
        }
        
        /**
         */
        private void goToOppositeLocation() {
	    if (oppoLocation != null) {
		assert oppoLocation.getFileObject() != null;
		callback.foundLocation(currLocation.getFileObject(), new LocationResult(oppoLocation.getFileObject(), -1));
	    }
	    if (oppoLocationIT != null) {
		assert oppoLocationIT.getFileObject() != null;
		callback.foundLocation(currLocation.getFileObject(), new LocationResult(oppoLocationIT.getFileObject(), -1));
	    }
        }
        
        /**
         */
        private void displayNoOppositeLocationFound() {
            String sourceClsName;
            FileObject fileObj = currLocation.getFileObject();
            sourceClsName = srcClassPath.getResourceName(fileObj, '.', false);
            String msgKey = !fileObj.isFolder()
                            ? "MSG_test_class_not_found"                //NOI18N
                            : (sourceClsName.length() != 0)
                              ? "MSG_testsuite_class_not_found"         //NOI18N
                              : "MSG_testsuite_class_not_found_def_pkg";//NOI18N
            callback.foundLocation(currLocation.getFileObject(), 
                    new LocationResult(NbBundle.getMessage(getClass(), msgKey, sourceClsName)));
        }
    }
    
    /**
     * Checks whether this action should be enabled for &quot;Go To Test&quot;
     * or for &quot;Go To Tested Class&quot or whether it should be disabled.
     * 
     * @return  {@code Boolean.TRUE} if this action should be enabled for
     *          &quot;Go To Test&quot;,<br />
     *          {@code Boolean.FALSE} if this action should be enabled for
     *          &quot;Go To Tested Class&quot;,<br />
     *          {@code null} if this action should be disabled
     */
    private Boolean checkDirection(FileObject fileObj) {
        ClassPath srcCP;
        FileObject fileObjRoot;
        
        boolean isJavaFile = false;
        boolean sourceToTest = true;
        boolean enabled = (fileObj != null)
          && (fileObj.isFolder() || (isJavaFile = JUnitTestUtil.isJavaFile(fileObj)))
          && ((srcCP = ClassPath.getClassPath(fileObj, ClassPath.SOURCE)) != null)
          && ((fileObjRoot = srcCP.findOwnerRoot(fileObj)) != null)
          && ((UnitTestForSourceQuery.findUnitTests(fileObjRoot).length != 0)
              || (sourceToTest = false)         //side effect - assignment
              || isJavaFile && (UnitTestForSourceQuery.findSources(fileObjRoot).length != 0));
        
        return enabled ? Boolean.valueOf(sourceToTest)
                       : null;
    }
    
    public boolean appliesTo(FileObject fo) {
        Project project = FileOwnerQuery.getOwner(fo);
        if (project != null) {
            JUnitPlugin plugin = JUnitTestUtil.getPluginForProject(project);
	    boolean applies = false;
            if (plugin instanceof DefaultPlugin) {
                Location loc = new Location(fo);
                Location test = ((DefaultPlugin) plugin).getTestLocation(loc);
                Location tested = ((DefaultPlugin) plugin).getTestedLocation(loc);
                applies = JUnitTestUtil.isJavaFile(fo) && (test != null || tested != null);
            }
	    if(applies) {
		return true;
	    } else {
		plugin = JUnitTestUtil.getITPluginForProject(project);
		if (plugin instanceof DefaultITPlugin) {
		    Location loc = new Location(fo);
		    Location test = ((DefaultITPlugin) plugin).getTestLocation(loc);
		    Location tested = ((DefaultITPlugin) plugin).getTestedLocation(loc);
		    return JUnitTestUtil.isJavaFile(fo) && (test != null || tested != null);
		}
	    }
        }
        return JUnitTestUtil.isJavaFile(fo);
    }

    public FileType getFileType(FileObject fo) {
        Boolean b = checkDirection(fo);
        
        if (b == null) {
            return FileType.NEITHER;
        } else if (b.booleanValue()) {
            return FileType.TESTED;
        } else {
            return FileType.TEST;
        }
    }
}