/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.bck2brwsr.ide.editor;

 import com.sun.source.tree.AnnotationTree;

 import com.sun.source.tree.AssignmentTree;

 import com.sun.source.tree.CompilationUnitTree;

 import com.sun.source.tree.ExpressionTree;

 import com.sun.source.tree.LiteralTree;

 import com.sun.source.tree.MethodTree;

 import com.sun.source.util.SourcePositions;

 import com.sun.source.util.TreePath;

 import com.sun.source.util.TreePathScanner;

 import com.sun.source.util.Trees;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.List;

 import java.util.concurrent.atomic.AtomicBoolean;

 import javax.lang.model.element.TypeElement;

 import javax.swing.text.Document;

 import org.netbeans.api.editor.mimelookup.MimeRegistration;

 import org.netbeans.api.java.source.CompilationInfo;

 import org.netbeans.api.java.source.JavaParserResultTask;

 import org.netbeans.api.java.source.JavaSource;

 import org.netbeans.api.lexer.Language;

 import org.netbeans.api.lexer.TokenHierarchy;

 import org.netbeans.api.lexer.TokenSequence;

 import org.netbeans.modules.parsing.api.Snapshot;

 import org.netbeans.modules.parsing.spi.Parser;

 import org.netbeans.modules.parsing.spi.Scheduler;

 import org.netbeans.modules.parsing.spi.SchedulerEvent;

 import org.netbeans.modules.parsing.spi.SchedulerTask;

 import org.netbeans.modules.parsing.spi.TaskFactory;

 import org.openide.util.Exceptions;

 /**

  *

  * @author Tomas Zezula

  */

 public final class JSEmbeddingProvider extends JavaParserResultTask<Parser.Result> {

     private static final int PRIORITY = 1000;

     private static final String JS_ANNOTATION = "org.apidesign.bck2brwsr.core.JavaScriptBody";  //NOI18N

     private static final String BODY = "body";                            //NOI18N

     private static final String JAVA_MIME_TYPE = "text/x-java";           //NOI18N

     private static final String JAVASCRIPT_MIME_TYPE = "text/javascript"; //NOI18N

     private final AtomicBoolean canceled = new AtomicBoolean();

     private JSEmbeddingProvider() {

         super(JavaSource.Phase.ELEMENTS_RESOLVED);

     }

     @Override

     public int getPriority() {

         return PRIORITY;

     }

     @Override

     public void cancel() {

         canceled.set(true);

     }

     @Override

     public Class<? extends Scheduler> getSchedulerClass() {

         return Scheduler.EDITOR_SENSITIVE_TASK_SCHEDULER;

     }

     @Override

     public void run(Parser.Result t, SchedulerEvent se) {

         canceled.set(false);

         final CompilationInfo ci = CompilationInfo.get(t);

         final CompilationUnitTree cu = ci.getCompilationUnit();

         final Trees trees = ci.getTrees();

         final SourcePositions sp = trees.getSourcePositions();

         final Finder f = new Finder(trees);

         final List<LiteralTree> result = new ArrayList<LiteralTree>();

         f.scan(cu, result);

         if (!result.isEmpty()) {

             try {

                 final TokenHierarchy<Document> tk = TokenHierarchy.get(ci.getDocument());

                 final Language<?> java = Language.find(JAVA_MIME_TYPE);

                 final Language<?> javaScript = Language.find(JAVASCRIPT_MIME_TYPE);

                 if (java != null && javaScript != null) {

                     final TokenSequence<?> seq = tk.tokenSequence(java);

                     if (seq != null) {

                         for (LiteralTree lt : result) {

                             final int start = (int) sp.getStartPosition(cu, lt);

                             final int end = (int) sp.getEndPosition(cu, lt);

                             seq.move(start);

                             while (seq.moveNext() && seq.offset() < end) {

                                 seq.createEmbedding(javaScript, 1, 1, true);

                             }

                         }

                     }

                 }

             } catch (IOException ioe) {

                 Exceptions.printStackTrace(ioe);

             }

         }

     }

     private static final class Finder extends TreePathScanner<Void, List<? super LiteralTree>> {

         private final Trees trees;

         private CompilationUnitTree cu;

         private boolean inEmbedding;

         Finder(final Trees trees) {

             this.trees = trees;

         }

         @Override

         public Void visitCompilationUnit(

                 final CompilationUnitTree unit,

                 final List p) {

             this.cu = unit;

             return super.visitCompilationUnit(unit, p);

         }

         @Override

         public Void visitMethod(

                 final MethodTree m,

                 final List<? super LiteralTree> p) {

             for (AnnotationTree a : m.getModifiers().getAnnotations()) {

                 final TypeElement ae = (TypeElement) trees.getElement(TreePath.getPath(cu, a.getAnnotationType()));

                 if (ae != null && JS_ANNOTATION.contentEquals(ae.getQualifiedName())) {

                     final List<? extends ExpressionTree> args =  a.getArguments();

                     for (ExpressionTree kvp : args) {

                         if (kvp instanceof AssignmentTree) {

                             final AssignmentTree assignemt = (AssignmentTree) kvp;

                             if (BODY.equals(assignemt.getVariable().toString())) {

                                 inEmbedding = true;

                                 try {

                                     scan(assignemt.getExpression(), p);

                                 } finally {

                                     inEmbedding = false;

                                 }

                             }

                         }

                     }

                 }

             }

             return null;

         }

         @Override

         public Void visitLiteral(LiteralTree node, List<? super LiteralTree> p) {

             if (inEmbedding) {

                 p.add(node);

             }

             return super.visitLiteral(node, p);

         }

     }

     @MimeRegistration(

             service = TaskFactory.class,

             mimeType = JAVA_MIME_TYPE)

     public static final class Factory extends TaskFactory {

         @Override

         public Collection<? extends SchedulerTask> create(Snapshot snpsht) {

             return Collections.singleton(new JSEmbeddingProvider());

         }

     }

 }