/*

 * Copyright (c) 2013, 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.

 */

/*

 * @test

 * @summary Ensuring javax.lang.model.**, javax.tools.**, javax.annotation.processing.**

 *          and com.sun.source.** don't export inappropriate types.

 * @library /tools/javac/lib

 * @modules java.compiler

 *          jdk.compiler

 * @build JavacTestingAbstractProcessor NoPrivateTypesExported

 * @compile -processor NoPrivateTypesExported NoPrivateTypesExported.java

 */

import java.lang.annotation.Documented;

import java.util.Arrays;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import javax.annotation.processing.RoundEnvironment;

import javax.lang.model.element.AnnotationMirror;

import javax.lang.model.element.AnnotationValue;

import javax.lang.model.element.Element;

import javax.lang.model.element.ElementKind;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.PackageElement;

import javax.lang.model.element.TypeElement;

import javax.lang.model.element.TypeParameterElement;

import javax.lang.model.element.VariableElement;

import javax.lang.model.type.ArrayType;

import javax.lang.model.type.DeclaredType;

import javax.lang.model.type.IntersectionType;

import javax.lang.model.type.TypeMirror;

import javax.lang.model.type.TypeVariable;

import javax.lang.model.type.WildcardType;

import javax.tools.Diagnostic.Kind;

public class NoPrivateTypesExported extends JavacTestingAbstractProcessor {

    private static final String[] javaxLangModelPackages = new String[] {

        "javax.lang.model",

        "javax.lang.model.element",

        "javax.lang.model.type",

        "javax.lang.model.util",

    };

    private static final Set<String> javaxLangModelAcceptable;

    private static final String[] javaxToolsProcessingPackages = new String[] {

        "javax.annotation.processing",

        "javax.tools",

    };

    private static final Set<String> javaxToolsProcessingAcceptable;

    private static final String[] comSunSourcePackages = new String[] {

        "com.sun.source.doctree",

        "com.sun.source.tree",

        "com.sun.source.util"

    };

    private static final Set<String> comSunSourceAcceptable;

    static {

        javaxLangModelAcceptable = new HashSet<>(Arrays.asList(

            "java.io.",

            "java.lang.",

            "java.net.",

            "java.nio.",

            "java.util.",

            "javax.lang.model.",

            "javax.annotation.processing.SupportedSourceVersion",

            "jdk.Exported"

        ));

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

        javaxToolsProcessingAcceptableTemp.addAll(javaxLangModelAcceptable);

        javaxToolsProcessingAcceptableTemp.addAll(Arrays.asList(

                "javax.annotation.processing.",

                "javax.tools."

        ));

        javaxToolsProcessingAcceptable = javaxToolsProcessingAcceptableTemp;

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

        comSunSourceAcceptableTemp.addAll(javaxToolsProcessingAcceptable);

        comSunSourceAcceptableTemp.addAll(Arrays.asList(

                "com.sun.source.doctree.",

                "com.sun.source.tree.",

                "com.sun.source.util."

        ));

        comSunSourceAcceptable = comSunSourceAcceptableTemp;

    }

    @Override

    public boolean process(Set<? extends TypeElement> annotations,

                           RoundEnvironment roundEnv) {

        if (roundEnv.processingOver()) {

            verifyPackage(javaxLangModelPackages, javaxLangModelAcceptable);

            verifyPackage(javaxToolsProcessingPackages, javaxToolsProcessingAcceptable);

            verifyPackage(comSunSourcePackages, comSunSourceAcceptable);

        }

        return true;

    }

    private void verifyPackage(String[] packagesToTest, Set<String> acceptable) {

        for (String packageToTest : packagesToTest) {

            PackageElement packageElement = processingEnv.getElementUtils()

                    .getPackageElement(packageToTest);

            verifyReferredTypesAcceptable(packageElement, acceptable);

        }

    }

    private void verifyReferredTypesAcceptable(Element rootElement,

                                               final Set<String> acceptable) {

        new ElementScanner<Void, Void>() {

            @Override public Void visitType(TypeElement e, Void p) {

                verifyTypeAcceptable(e.getSuperclass(), acceptable);

                verifyTypesAcceptable(e.getInterfaces(), acceptable);

                scan(e.getTypeParameters(), p);

                scan(e.getEnclosedElements(), p);

                verifyAnnotations(e.getAnnotationMirrors(), acceptable);

                return null;

            }

            @Override public Void visitTypeParameter(TypeParameterElement e, Void p) {

                verifyTypesAcceptable(e.getBounds(), acceptable);

                scan(e.getEnclosedElements(), p);

                verifyAnnotations(e.getAnnotationMirrors(), acceptable);

                return null;

            }

            @Override public Void visitPackage(PackageElement e, Void p) {

                scan(e.getEnclosedElements(), p);

                verifyAnnotations(e.getAnnotationMirrors(), acceptable);

                return null;

            }

            @Override public Void visitVariable(VariableElement e, Void p) {

                verifyTypeAcceptable(e.asType(), acceptable);

                scan(e.getEnclosedElements(), p);

                verifyAnnotations(e.getAnnotationMirrors(), acceptable);

                return null;

            }

            @Override

            public Void visitExecutable(ExecutableElement e, Void p) {

                scan(e.getTypeParameters(), p);

                verifyTypeAcceptable(e.getReturnType(), acceptable);

                scan(e.getParameters(), p);

                verifyTypesAcceptable(e.getThrownTypes(), acceptable);

                scan(e.getEnclosedElements(), p);

                verifyAnnotations(e.getAnnotationMirrors(), acceptable);

                return null;

            }

        }.scan(rootElement, null);

    }

    private void verifyAnnotations(Iterable<? extends AnnotationMirror> annotations,

                                   Set<String> acceptable) {

        for (AnnotationMirror mirror : annotations) {

            Element annotationElement = mirror.getAnnotationType().asElement();

            if (annotationElement.getAnnotation(Documented.class) == null) {

                note("Ignoring undocumented annotation: " + mirror.getAnnotationType());

            }

            verifyTypeAcceptable(mirror.getAnnotationType(), acceptable);

            for (AnnotationValue value : mirror.getElementValues().values()) {

                verifyAnnotationValue(value, acceptable);

            }

        }

    }

    private void verifyAnnotationValue(AnnotationValue value,

                                       final Set<String> acceptable) {

        value.accept(new SimpleAnnotationValueVisitor<Void, Void>() {

            @Override public Void visitType(TypeMirror t, Void p) {

                verifyTypeAcceptable(t, acceptable);

                return null;

            }

            @Override

            public Void visitEnumConstant(VariableElement c, Void p) {

                verifyReferredTypesAcceptable(c, acceptable);

                return null;

            }

            @Override public Void visitArray(List<? extends AnnotationValue> vals,

                                             Void p) {

                for (AnnotationValue val : vals) {

                    val.accept(this, p);

                }

                return null;

            }

            @Override protected Void defaultAction(Object o, Void p) {

                error("Unexpected AnnotationValue: " + o.toString());

                return super.defaultAction(o, p);

            }

        }, null);

    }

    private void verifyTypesAcceptable(Iterable<? extends TypeMirror> types,

                                       Set<String> acceptable) {

        if (types == null) return ;

        for (TypeMirror type : types) {

            verifyTypeAcceptable(type, acceptable);

        }

    }

    private void verifyTypeAcceptable(TypeMirror type, Set<String> acceptable) {

        if (type == null) return ;

        verifyAnnotations(type.getAnnotationMirrors(), acceptable);

        switch (type.getKind()) {

            case BOOLEAN: case BYTE: case CHAR: case DOUBLE: case FLOAT:

            case INT: case LONG: case SHORT: case VOID: case NONE: case NULL:

                return ;

            case DECLARED:

                DeclaredType dt = (DeclaredType) type;

                TypeElement outermostTypeElement = outermostTypeElement(dt.asElement());

                String outermostType = outermostTypeElement.getQualifiedName().toString();

                boolean isAcceptable = false;

                for (String acceptablePackage : acceptable) {

                    if (outermostType.startsWith(acceptablePackage)) {

                        isAcceptable = true;

                        break;

                    }

                }

                if (!isAcceptable) {

                    error("Type not acceptable for this API: " + dt.toString());

                }

                for (TypeMirror bound : dt.getTypeArguments()) {

                    verifyTypeAcceptable(bound, acceptable);

                }

                break;

            case ARRAY:

                verifyTypeAcceptable(((ArrayType) type).getComponentType(), acceptable);

                break;

            case INTERSECTION:

                for (TypeMirror element : ((IntersectionType) type).getBounds()) {

                    verifyTypeAcceptable(element, acceptable);

                }

                break;

            case TYPEVAR:

                verifyTypeAcceptable(((TypeVariable) type).getLowerBound(), acceptable);

                verifyTypeAcceptable(((TypeVariable) type).getUpperBound(), acceptable);

                break;

            case WILDCARD:

                verifyTypeAcceptable(((WildcardType) type).getExtendsBound(), acceptable);

                verifyTypeAcceptable(((WildcardType) type).getSuperBound(), acceptable);

                break;

            default:

                error("Type not acceptable for this API: " + type.toString());

                break;

        }

    }

    private TypeElement outermostTypeElement(Element el) {

        while (el.getEnclosingElement().getKind() != ElementKind.PACKAGE) {

            el = el.getEnclosingElement();

        }

        return (TypeElement) el;

    }

    private void error(String text) {

        processingEnv.getMessager().printMessage(Kind.ERROR, text);

    }

    private void note(String text) {

        processingEnv.getMessager().printMessage(Kind.NOTE, text);

    }

}