/**

  * 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.core.impl;

 import java.util.Collections;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Set;

 import javax.annotation.processing.AbstractProcessor;

 import javax.annotation.processing.Completion;

 import javax.annotation.processing.Completions;

 import javax.annotation.processing.Messager;

 import javax.annotation.processing.Processor;

 import javax.annotation.processing.RoundEnvironment;

 import javax.lang.model.element.AnnotationMirror;

 import javax.lang.model.element.Element;

 import javax.lang.model.element.ElementKind;

 import javax.lang.model.element.ExecutableElement;

 import javax.lang.model.element.TypeElement;

 import javax.lang.model.element.VariableElement;

 import javax.lang.model.type.TypeKind;

 import javax.tools.Diagnostic;

 import org.apidesign.bck2brwsr.core.JavaScriptBody;

 import org.openide.util.lookup.ServiceProvider;

 /**

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 @ServiceProvider(service = Processor.class)

 public final class JavaScriptProcesor extends AbstractProcessor {

     @Override

     public Set<String> getSupportedAnnotationTypes() {

         Set<String> set = new HashSet<>();

         set.add(JavaScriptBody.class.getName());

         return set;

     }

     @Override

     public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {

         final Messager msg = processingEnv.getMessager();

         for (Element e : roundEnv.getElementsAnnotatedWith(JavaScriptBody.class)) {

             if (e.getKind() != ElementKind.METHOD && e.getKind() != ElementKind.CONSTRUCTOR) {

                 continue;

             }

             ExecutableElement ee = (ExecutableElement)e;

             List<? extends VariableElement> params = ee.getParameters();

             JavaScriptBody jsb = e.getAnnotation(JavaScriptBody.class);

             if (jsb == null) {

                 continue;

             }

             String[] arr = jsb.args();

             if (params.size() != arr.length) {

                 msg.printMessage(Diagnostic.Kind.ERROR, "Number of args arguments does not match real arguments!", e);

             }

             if (ee.getReturnType().getKind() == TypeKind.LONG) {

                 msg.printMessage(Diagnostic.Kind.WARNING, "Don't return long. Return double and convert it to long in Java code.", e);

             }

         }

         return true;

     }

     @Override

     public Iterable<? extends Completion> getCompletions(Element e, 

         AnnotationMirror annotation, ExecutableElement member, String userText

     ) {

         StringBuilder sb = new StringBuilder();

         if (e.getKind() == ElementKind.METHOD && member.getSimpleName().contentEquals("args")) {

             ExecutableElement ee = (ExecutableElement) e;

             String sep = "";

             sb.append("{ ");

             for (VariableElement ve : ee.getParameters()) {

                 sb.append(sep).append('"').append(ve.getSimpleName())

                     .append('"');

                 sep = ", ";

             }

             sb.append(" }");

             return Collections.nCopies(1, Completions.of(sb.toString()));

         }

         return null;

     }

 }