/*

 * Copyright (c) 2014, 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

 * @bug 8029161 8029376

 */

import com.sun.source.tree.CompilationUnitTree;

import com.sun.source.tree.IdentifierTree;

import com.sun.source.tree.MemberSelectTree;

import com.sun.source.util.JavacTask;

import com.sun.source.util.TreePathScanner;

import com.sun.source.util.Trees;

import com.sun.tools.javac.api.JavacTool;

import java.io.IOException;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import javax.lang.model.element.Element;

import javax.lang.model.element.ElementKind;

import javax.lang.model.type.TypeKind;

import javax.tools.Diagnostic;

import javax.tools.DiagnosticListener;

import javax.tools.JavaFileObject;

import javax.tools.SimpleJavaFileObject;

public class VerifyErroneousAnnotationsAttributed {

    public static void main(String... args) throws IOException, URISyntaxException {

        new VerifyErroneousAnnotationsAttributed().run();

    }

    void run() {

        int failCount = 0;

        for (String ann : generateAnnotations()) {

            String code = PATTERN.replace("PLACEHOLDER", ann);

            try {

                validate(code);

            } catch (Throwable t) {

                System.out.println("Failed for: ");

                System.out.println(code);

                t.printStackTrace(System.out);

                failCount++;

            }

        }

        if (failCount > 0) {

            throw new IllegalStateException("failed sub-tests: " + failCount);

        }

    }

    List<String> generateAnnotations() {

        List<String> result = new ArrayList<>();

        result.addAll(Kind.ANNOTATION.generateValue(2, true));

        result.addAll(Kind.ANNOTATION.generateValue(2, false));

        return result;

    }

    enum Kind {

        INT("i", "ValueInt") {

            @Override public List<String> generateValue(int depth, boolean valid) {

                if (valid) {

                    return Arrays.asList("INT_VALUE");

                } else {

                    return Arrays.asList("BROKEN_INT_VALUE");

                }

            }

        },

        ANNOTATION("a", "ValueAnnotation") {

            @Override public List<String> generateValue(int depth, boolean valid) {

                String ad = "@Annotation" + depth + (valid ? "" : "Unknown");

                if (depth <= 0) {

                    return Arrays.asList(ad);

                }

                List<String> result = new ArrayList<>();

                final Kind[][] generateKindCombinations = new Kind[][] {

                    new Kind[] {Kind.INT},

                    new Kind[] {Kind.ANNOTATION},

                    new Kind[] {Kind.INT, Kind.ANNOTATION}

                };

                for (boolean generateAssignment : new boolean[] {false, true}) {

                    for (boolean generateValid : new boolean[] {false, true}) {

                        for (Kind[] generateKinds : generateKindCombinations) {

                            if (generateKinds.length > 1 && generateValid && !generateAssignment) {

                                //skip: the same code is generated for generateValid == false.

                                continue;

                            }

                            List<String> attributes = generateAttributes(generateAssignment,

                                    generateValid, depth, generateKinds);

                            String annotation;

                            if (generateAssignment) {

                                annotation = ad;

                            } else {

                                annotation = ad + generateKinds[0].annotationWithValueSuffix;

                            }

                            for (String attr : attributes) {

                                result.add(annotation + "(" + attr + ")");

                            }

                        }

                    }

                }

                return result;

            }

            List<String> generateAttributes(boolean generateAssignment, boolean valid, int depth,

                                            Kind... kinds) {

                List<List<String>> combinations = new ArrayList<>();

                for (boolean subValid : new boolean[] {false, true}) {

                    for (Kind k : kinds) {

                        String prefix;

                        if (generateAssignment) {

                            if (valid) {

                                prefix = k.validAttributeName + "=";

                            } else {

                                prefix = "invalid" + k.validAttributeName + "=";

                            }

                        } else {

                            prefix = "";

                        }

                        List<String> combination = new ArrayList<>();

                        combinations.add(combination);

                        for (String val : k.generateValue(depth - 1, subValid)) {

                            combination.add(prefix + val);

                        }

                    }

                }

                List<String> result = new ArrayList<>();

                combine(combinations, new StringBuilder(), result);

                return result;

            }

            void combine(List<List<String>> combinations, StringBuilder current, List<String> to) {

                if (combinations.isEmpty()) {

                    to.add(current.toString());

                    return ;

                }

                int currLen = current.length();

                for (String str : combinations.get(0)) {

                    if (current.length() > 0) current.append(", ");

                    current.append(str);

                    combine(combinations.subList(1, combinations.size()), current, to);

                    current.delete(currLen, current.length());

                }

            }

        };

        String validAttributeName;

        String annotationWithValueSuffix;

        private Kind(String validAttributeName, String annotationWithValueSuffix) {

            this.validAttributeName = validAttributeName;

            this.annotationWithValueSuffix = annotationWithValueSuffix;

        }

        public abstract List<String> generateValue(int depth, boolean valid);

    }

    private static final String PATTERN =

            "public class Test {\n" +

            "    public static final int INT_VALUE = 1;\n" +

            "    @interface Annotation0 {}\n" +

            "    @interface Annotation1 {int i() default 0; Annotation0 a() default @Annotation0; }\n" +

            "    @interface Annotation2 {int i() default 0; Annotation1 a() default @Annotation1; }\n" +

            "    @interface Annotation1ValueInt {int value() default 0; }\n" +

            "    @interface Annotation2ValueInt {int value() default 0; }\n" +

            "    @interface Annotation1ValueAnnotation {Annotation0 a() default @Annotation0; }\n" +

            "    @interface Annotation2ValueAnnotation {Annotation1 a() default @Annotation1; }\n" +

            "    PLACEHOLDER\n" +

            "    private void test() { }\n" +

            "}";

    static final class TestCase {

        final String code;

        final boolean valid;

        public TestCase(String code, boolean valid) {

            this.code = code;

            this.valid = valid;

        }

    }

    final JavacTool tool = JavacTool.create();

    final DiagnosticListener<JavaFileObject> devNull = new DiagnosticListener<JavaFileObject>() {

        @Override public void report(Diagnostic<? extends JavaFileObject> diagnostic) {}

    };

    void validate(String code) throws IOException, URISyntaxException {

        JavacTask task = tool.getTask(null,

                                      null,

                                      devNull,

                                      Arrays.asList("-XDshouldStopPolicy=FLOW"),

                                      null,

                                      Arrays.asList(new MyFileObject(code)));

        final Trees trees = Trees.instance(task);

        final CompilationUnitTree cut = task.parse().iterator().next();

        task.analyze();

        //ensure all the annotation attributes are annotated meaningfully

        //all the attributes in the test file should contain either an identifier

        //or a select, so only checking those for a reasonable Element/Symbol.

        new TreePathScanner<Void, Void>() {

            @Override

            public Void visitIdentifier(IdentifierTree node, Void p) {

                verifyAttributedMeaningfully();

                return super.visitIdentifier(node, p);

            }

            @Override

            public Void visitMemberSelect(MemberSelectTree node, Void p) {

                verifyAttributedMeaningfully();

                return super.visitMemberSelect(node, p);

            }

            private void verifyAttributedMeaningfully() {

                Element el = trees.getElement(getCurrentPath());

                if (el == null || el.getKind() == ElementKind.OTHER ||

                        el.asType().getKind() == TypeKind.OTHER) {

                    throw new IllegalStateException("Not attributed properly: " +

                            getCurrentPath().getParentPath().getLeaf());

                }

            }

        }.scan(cut, null);

    }

    static class MyFileObject extends SimpleJavaFileObject {

        private final String text;

        public MyFileObject(String text) {

            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);

            this.text = text;

        }

        @Override

        public CharSequence getCharContent(boolean ignoreEncodingErrors) {

            return text;

        }

    }

}