/*

 * Copyright (c) 2010, 2015, Oracle and/or its affiliates. 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

import java.lang.reflect.Layer;

import java.lang.reflect.Module;

import java.util.*;

import javax.annotation.processing.*;

import javax.lang.model.SourceVersion;

import javax.lang.model.util.*;

import static javax.lang.model.SourceVersion.*;

/**

 * An abstract annotation processor tailored to {@code javac} regression testing.

 */

public abstract class JavacTestingAbstractProcessor extends AbstractProcessor {

    private static final Set<String> allAnnotations;

    static {

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

        tmp.add("*");

        allAnnotations = Collections.unmodifiableSet(tmp);

    }

    protected Elements eltUtils;

    protected Elements elements;

    protected Types    typeUtils;

    protected Types    types;

    protected Filer    filer;

    protected Messager messager;

    protected Map<String, String> options;

    /**

     * Constructor for subclasses to call.

     */

    protected JavacTestingAbstractProcessor() {

        super();

    }

    /**

     * Return the latest source version. Unless this method is

     * overridden, an {@code IllegalStateException} will be thrown if a

     * subclass has a {@code SupportedSourceVersion} annotation.

     */

    @Override

    public SourceVersion getSupportedSourceVersion() {

        SupportedSourceVersion ssv = this.getClass().getAnnotation(SupportedSourceVersion.class);

        if (ssv != null)

            throw new IllegalStateException("SupportedSourceVersion annotation not supported here.");

        return SourceVersion.latest();

    }

    /**

     * If the processor class is annotated with {@link

     * SupportedAnnotationTypes}, return an unmodifiable set with the

     * same set of strings as the annotation.  If the class is not so

     * annotated, a one-element set containing {@code "*"} is returned

     * to indicate all annotations are processed.

     *

     * @return the names of the annotation types supported by this

     * processor, or an empty set if none

     */

    @Override

    public Set<String> getSupportedAnnotationTypes() {

        SupportedAnnotationTypes sat = this.getClass().getAnnotation(SupportedAnnotationTypes.class);

        if (sat != null)

            return super.getSupportedAnnotationTypes();

        else

            return allAnnotations;

    }

    @Override

    public void init(ProcessingEnvironment processingEnv) {

        super.init(processingEnv);

        elements = eltUtils  = processingEnv.getElementUtils();

        types = typeUtils = processingEnv.getTypeUtils();

        filer     = processingEnv.getFiler();

        messager  = processingEnv.getMessager();

        options   = processingEnv.getOptions();

    }

    protected void addExports(String moduleName, String... packageNames) {

        for (String packageName : packageNames) {

            try {

                Layer layer = Layer.boot();

                Optional<Module> m = layer.findModule(moduleName);

                if (!m.isPresent())

                    throw new Error("module not found: " + moduleName);

                m.get().addExports(packageName, getClass().getModule());

            } catch (Exception e) {

                throw new Error("failed to add exports for " + moduleName + "/" + packageName);

            }

        }

    }

    /*

     * The set of visitors below will directly extend the most recent

     * corresponding platform visitor type.

     */

    @SupportedSourceVersion(RELEASE_9)

    public static abstract class AbstractAnnotationValueVisitor<R, P> extends AbstractAnnotationValueVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses to call.

         */

        protected AbstractAnnotationValueVisitor() {

            super();

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static abstract class AbstractElementVisitor<R, P> extends AbstractElementVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses to call.

         */

        protected AbstractElementVisitor(){

            super();

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static abstract class AbstractTypeVisitor<R, P> extends AbstractTypeVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses to call.

         */

        protected AbstractTypeVisitor() {

            super();

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class ElementKindVisitor<R, P> extends ElementKindVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses; uses {@code null} for the

         * default value.

         */

        protected ElementKindVisitor() {

            super(null);

        }

        /**

         * Constructor for concrete subclasses; uses the argument for the

         * default value.

         *

         * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

         */

        protected ElementKindVisitor(R defaultValue) {

            super(defaultValue);

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class ElementScanner<R, P> extends ElementScanner9<R, P> {

        /**

         * Constructor for concrete subclasses; uses {@code null} for the

         * default value.

         */

        protected ElementScanner(){

            super(null);

        }

        /**

         * Constructor for concrete subclasses; uses the argument for the

         * default value.

         */

        protected ElementScanner(R defaultValue){

            super(defaultValue);

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class SimpleAnnotationValueVisitor<R, P> extends SimpleAnnotationValueVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses; uses {@code null} for the

         * default value.

         */

        protected SimpleAnnotationValueVisitor() {

            super(null);

        }

        /**

         * Constructor for concrete subclasses; uses the argument for the

         * default value.

         *

         * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

         */

        protected SimpleAnnotationValueVisitor(R defaultValue) {

            super(defaultValue);

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class SimpleElementVisitor<R, P> extends SimpleElementVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses; uses {@code null} for the

         * default value.

         */

        protected SimpleElementVisitor(){

            super(null);

        }

        /**

         * Constructor for concrete subclasses; uses the argument for the

         * default value.

         *

         * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

         */

        protected SimpleElementVisitor(R defaultValue){

            super(defaultValue);

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class SimpleTypeVisitor<R, P> extends SimpleTypeVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses; uses {@code null} for the

         * default value.

         */

        protected SimpleTypeVisitor(){

            super(null);

        }

        /**

         * Constructor for concrete subclasses; uses the argument for the

         * default value.

         *

         * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

         */

        protected SimpleTypeVisitor(R defaultValue){

            super(defaultValue);

        }

    }

    @SupportedSourceVersion(RELEASE_9)

    public static class TypeKindVisitor<R, P> extends TypeKindVisitor9<R, P> {

        /**

         * Constructor for concrete subclasses to call; uses {@code null}

         * for the default value.

         */

        protected TypeKindVisitor() {

            super(null);

        }

        /**

         * Constructor for concrete subclasses to call; uses the argument

         * for the default value.

         *

         * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

         */

        protected TypeKindVisitor(R defaultValue) {

            super(defaultValue);

        }

    }

}