/**

 * Java 4 Browser Bytecode Translator

 * Copyright (C) 2012-2012 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.htmlpage;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStreamWriter;

import java.io.Writer;

import java.util.Locale;

import java.util.Set;

import javax.annotation.processing.AbstractProcessor;

import javax.annotation.processing.Processor;

import javax.annotation.processing.RoundEnvironment;

import javax.annotation.processing.SupportedAnnotationTypes;

import javax.lang.model.element.Element;

import javax.lang.model.element.PackageElement;

import javax.lang.model.element.TypeElement;

import javax.tools.Diagnostic;

import javax.tools.FileObject;

import javax.tools.StandardLocation;

import org.apidesign.bck2brwsr.htmlpage.api.Page;

import org.openide.util.lookup.ServiceProvider;

/** Annotation processor to process an XHTML page and generate appropriate 

 * "id" file.

 *

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

 */

@ServiceProvider(service=Processor.class)

@SupportedAnnotationTypes("org.apidesign.bck2brwsr.htmlpage.api.Page")

public final class PageProcessor extends AbstractProcessor {

    @Override

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

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

            Page p = e.getAnnotation(Page.class);

            PackageElement pe = (PackageElement)e;

            String pkg = pe.getQualifiedName().toString();

            ProcessPage pp;

            try {

                InputStream is = openStream(pkg, p.xhtml());

                pp = ProcessPage.readPage(is);

                is.close();

            } catch (IOException iOException) {

                processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, "Can't read " + p.xhtml(), e);

                return false;

            }

            Writer w;

            try {

                FileObject java = processingEnv.getFiler().createSourceFile(pkg + '.' + p.name(), e);

                w = new OutputStreamWriter(java.openOutputStream());

                w.append("package " + pkg + ";\n");

                w.append("import org.apidesign.bck2brwsr.htmlpage.api.*;\n");

                w.append("class ").append(p.name()).append(" {\n");

                for (String id : pp.ids()) {

                    String tag = pp.tagNameForId(id);

                    String type = type(tag);

                    w.append("  ").append("public static final ").

                        append(type).append(' ').append(cnstnt(id)).append(" = new ").

                        append(type).append("(\"").append(id).append("\");\n");

                }

                w.append("}");

                w.close();

            } catch (IOException ex) {

                processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, "Can't create " + p.name() + ".java", e);

                return false;

            }

        }

        return true;

    }

    private InputStream openStream(String pkg, String name) throws IOException {

        FileObject fo = processingEnv.getFiler().getResource(

            StandardLocation.SOURCE_PATH, pkg, name);

        try {

            return fo.openInputStream();

        } catch (IOException ex) {

            return processingEnv.getFiler().getResource(StandardLocation.CLASS_OUTPUT, pkg, name).openInputStream();

        }

    }

    private static String type(String tag) {

        if (tag.equals("title")) {

            return "Title";

        }

        if (tag.equals("button")) {

            return "Button";

        }

        if (tag.equals("input")) {

            return "Input";

        }

        return "Element";

    }

    private static String cnstnt(String id) {

        return id.toUpperCase(Locale.ENGLISH).replace('.', '_');

    }

}