/*

 * Copyright (c) 2018, Google Inc. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 */

import static java.nio.charset.StandardCharsets.UTF_8;

import java.io.IOError;

import java.io.IOException;

import java.io.OutputStream;

import java.util.Set;

import javax.annotation.processing.RoundEnvironment;

import javax.annotation.processing.SupportedAnnotationTypes;

import javax.lang.model.element.PackageElement;

import javax.lang.model.element.TypeElement;

@SupportedAnnotationTypes("*")

public class Processor extends JavacTestingAbstractProcessor {

    boolean first = true;

    @Override

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

        if (first) {

            // Annotations are present on the initial package-info loaded from the classpath.

            PackageElement p = processingEnv.getElementUtils().getPackageElement("p");

            if (p.getAnnotationMirrors().isEmpty()) {

                throw new AssertionError(

                        "expected package annotations: " + p.getAnnotationMirrors());

            }

            // Overwrite the package-info with a new unannotated package-info.

            try (OutputStream os =

                    processingEnv

                            .getFiler()

                            .createSourceFile("p.package-info")

                            .openOutputStream()) {

                os.write("package p;".getBytes(UTF_8));

            } catch (IOException e) {

                throw new IOError(e);

            }

            first = false;

        }

        // The package-info's symbol should be reset between rounds, and when annotation

        // processing is over the package-info should be unannotated.

        PackageElement p = processingEnv.getElementUtils().getPackageElement("p");

        if (roundEnv.processingOver()) {

            if (!p.getAnnotationMirrors().isEmpty()) {

                throw new AssertionError(

                        "expected no package annotations: " + p.getAnnotationMirrors());

            }

        }

        return false;

    }

}