/*

 * Copyright (c) 2015, 2019, 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 8072480 8203814

 * @summary Check the platform classpath contains the correct elements.

 * @library /tools/lib

 * @modules jdk.compiler/com.sun.tools.javac.code

 *          jdk.compiler/com.sun.tools.javac.api

 *          jdk.compiler/com.sun.tools.javac.main

 *          jdk.compiler/com.sun.tools.javac.platform

 *          jdk.compiler/com.sun.tools.javac.util

 *          jdk.jdeps/com.sun.tools.classfile

 *          jdk.jdeps/com.sun.tools.javap

 * @build toolbox.ToolBox ElementStructureTest

 * @run main ElementStructureTest

 */

import java.io.BufferedReader;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.io.Reader;

import java.io.Writer;

import java.net.URI;

import java.net.URL;

import java.net.URLClassLoader;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.security.MessageDigest;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.EnumSet;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import java.util.Map.Entry;

import java.util.ServiceLoader;

import java.util.Set;

import java.util.TreeMap;

import java.util.TreeSet;

import java.util.function.Predicate;

import java.util.regex.Pattern;

import java.util.stream.Stream;

import javax.lang.model.element.AnnotationMirror;

import javax.lang.model.element.AnnotationValue;

import javax.lang.model.element.Element;

import javax.lang.model.element.ElementVisitor;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.Modifier;

import javax.lang.model.element.ModuleElement;

import javax.lang.model.element.NestingKind;

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.TypeMirror;

import javax.tools.FileObject;

import javax.tools.JavaCompiler;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileObject;

import javax.tools.JavaFileObject.Kind;

import javax.tools.StandardLocation;

import javax.tools.ToolProvider;

import com.sun.source.util.JavacTask;

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.ConstantPoolException;

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

import com.sun.tools.javac.code.Symbol.CompletionFailure;

import com.sun.tools.javac.platform.PlatformProvider;

import toolbox.ToolBox;

/**To generate the hash values for version N, invoke this class like:

 *

 *     java ElementStructureTest generate-hashes $LANGTOOLS_DIR/make/data/symbols/include.list (<classes-for-N> N)+

 *

 * Where <classes-for-N> is the file produced by make/src/classes/build/tools/symbolgenerator/Probe.java.

 * So, to produce hashes for 6, 7 and 8, this command can be used:

 *

 *     java ElementStructureTest generate-hashes classes-6 6 classes-7 7 classes-8 8

 *

 * To inspect differences between the actual and expected output for version N, invoke this class like:

 *

 *     java ElementStructureTest generate-output $LANGTOOLS_DIR/make/data/symbols/include.list (<classes-for-N> N <actual-output-file> <expected-output-file>)+

 *

 * For example, to get the actual and expected output for 6 in /tmp/actual and /tmp/expected, respectively:

 *

 *     java ElementStructureTest generate-output $LANGTOOLS_DIR/make/data/symbols/include.list classes-6 6 /tmp/actual /tmp/expected

 */

public class ElementStructureTest {

    static final byte[] hash6 = new byte[] {

        (byte) 0x99, (byte) 0x34, (byte) 0x82, (byte) 0xCF,

        (byte) 0xE0, (byte) 0x53, (byte) 0xF3, (byte) 0x13,

        (byte) 0x4E, (byte) 0xCF, (byte) 0x49, (byte) 0x32,

        (byte) 0xB7, (byte) 0x52, (byte) 0x0F, (byte) 0x68

    };

    static final byte[] hash7 = new byte[] {

        (byte) 0x3C, (byte) 0x03, (byte) 0xEA, (byte) 0x4A,

        (byte) 0x62, (byte) 0xD2, (byte) 0x18, (byte) 0xE5,

        (byte) 0xA5, (byte) 0xC2, (byte) 0xB7, (byte) 0x85,

        (byte) 0x90, (byte) 0xFA, (byte) 0x98, (byte) 0xCD

    };

    static final byte[] hash8 = new byte[] {

        (byte) 0x0B, (byte) 0xEB, (byte) 0x16, (byte) 0xF5,

        (byte) 0x7F, (byte) 0xB0, (byte) 0x18, (byte) 0xF1,

        (byte) 0x78, (byte) 0x11, (byte) 0xED, (byte) 0x30,

        (byte) 0x19, (byte) 0x4D, (byte) 0xDE, (byte) 0x8A

    };

    final static Map<String, byte[]> version2Hash = new HashMap<>();

    static {

        version2Hash.put("6", hash6);

        version2Hash.put("7", hash7);

        version2Hash.put("8", hash8);

    }

    public static void main(String... args) throws Exception {

        if (args.length == 0) {

            new ElementStructureTest().doTest();

            return ;

        }

        switch (args[0]) {

            case "generate-hashes":

                new ElementStructureTest().generateHashes(args);

                break;

            case "generate-output":

                new ElementStructureTest().generateOutput(args);

                break;

            default:

                throw new IllegalStateException("Unrecognized request: " + args[0]);

        }

    }

    void doTest() throws Exception {

        for (PlatformProvider provider : ServiceLoader.load(PlatformProvider.class)) {

            for (String ver : provider.getSupportedPlatformNames()) {

                if (!version2Hash.containsKey(ver))

                    continue;

                try (ByteArrayOutputStream baos = new ByteArrayOutputStream(); Writer output = new OutputStreamWriter(baos, "UTF-8")) {

                    run(output, ver);

                    output.close();

                    byte[] actual = MessageDigest.getInstance("MD5").digest(baos.toByteArray());

                    if (!Arrays.equals(version2Hash.get(ver), actual))

                        throw new AssertionError("Wrong hash: " + toHex(actual) + " for version: " + ver);

                }

            }

        }

    }

    void generateHashes(String... args) throws Exception {

        Predicate<String> ignoreList = constructAcceptIgnoreList(args[1]);

        for (int i = 2; i < args.length; i += 2) {

            try (ByteArrayOutputStream baos = new ByteArrayOutputStream(); Writer output = new OutputStreamWriter(baos, "UTF-8")) {

                realClasses(args[i], ignoreList, output, args[i + 1]);

                output.close();

                System.err.println("version:" + args[i + 1] + "; " + toHex(MessageDigest.getInstance("MD5").digest(baos.toByteArray())));

            }

        }

    }

    void generateOutput(String... args) throws Exception {

        Predicate<String> ignoreList = constructAcceptIgnoreList(args[1]);

        for (int i = 2; i < args.length; i += 4) {

            try (Writer actual = Files.newBufferedWriter(Paths.get(args[i + 2]));

                 Writer expected = Files.newBufferedWriter(Paths.get(args[i + 3]))) {

                run(actual, args[i + 1]);

                realClasses(args[i], ignoreList, expected, args[i + 1]);

            }

        }

    }

    Predicate<String> constructAcceptIgnoreList(String fromFiles) throws IOException {

        StringBuilder acceptPattern = new StringBuilder();

        StringBuilder rejectPattern = new StringBuilder();

        for (String file : fromFiles.split(File.pathSeparator)) {

            try (Stream<String> lines = Files.lines(Paths.get(file))) {

                lines.forEach(line -> {

                    if (line.isEmpty())

                        return;

                    StringBuilder targetPattern;

                    switch (line.charAt(0)) {

                        case '+':

                            targetPattern = acceptPattern;

                            break;

                        case '-':

                            targetPattern = rejectPattern;

                            break;

                        default:

                            return ;

                    }

                    line = line.substring(1);

                    if (line.endsWith("/")) {

                        line += "[^/]*";

                    } else {

                        line += "|" + line + "$[^/]*";

                    }

                    line = line.replace("/", ".");

                    if (targetPattern.length() != 0)

                        targetPattern.append("|");

                    targetPattern.append(line);

                });

            }

        }

        Pattern accept = Pattern.compile(acceptPattern.toString());

        Pattern reject = Pattern.compile(rejectPattern.toString());

        return clazzName -> accept.matcher(clazzName).matches() && !reject.matcher(clazzName).matches();

    }

    private static String toHex(byte[] bytes) {

        StringBuilder hex = new StringBuilder();

        String delim = "";

        for (byte b : bytes) {

            hex.append(delim);

            hex.append(String.format("(byte) 0x%02X", b));

            delim = ", ";

        }

        return hex.toString();

    }

    void run(Writer output, String version) throws Exception {

        List<String> options = Arrays.asList("--release", version, "-classpath", "");

        List<ToolBox.JavaSource> files = Arrays.asList(new ToolBox.JavaSource("Test", ""));

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

        JavacTaskImpl task = (JavacTaskImpl) compiler.getTask(null, null, null, options, null, files);

        task.analyze();

        JavaFileManager fm = task.getContext().get(JavaFileManager.class);

        for (String pack : packages(fm)) {

            PackageElement packEl = task.getElements().getPackageElement(pack);

            if (packEl == null) {

                throw new AssertionError("Cannot find package: " + pack);

            }

            new ExhaustiveElementScanner(task, output, p -> true).visit(packEl);

        }

    }

    void realClasses(String location, Predicate<String> acceptor, Writer output, String version) throws Exception {

        Path classes = Paths.get(location);

        Map<String, JavaFileObject> className2File = new HashMap<>();

        Map<JavaFileObject, String> file2ClassName = new HashMap<>();

        try (BufferedReader descIn = Files.newBufferedReader(classes)) {

            String classFileData;

            while ((classFileData = descIn.readLine()) != null) {

                ByteArrayOutputStream data = new ByteArrayOutputStream();

                for (int i = 0; i < classFileData.length(); i += 2) {

                    data.write(Integer.parseInt(classFileData.substring(i, i + 2), 16));

                }

                JavaFileObject file = new ByteArrayJavaFileObject(data.toByteArray());

                try (InputStream in = new ByteArrayInputStream(data.toByteArray())) {

                    String name = ClassFile.read(in).getName().replace("/", ".");

                    className2File.put(name, file);

                    file2ClassName.put(file, name);

                } catch (IOException | ConstantPoolException ex) {

                    throw new IllegalStateException(ex);

                }

            }

        }

        try (JavaFileManager fm = new TestFileManager(className2File, file2ClassName)) {

            JavacTaskImpl task = (JavacTaskImpl) ToolProvider.getSystemJavaCompiler().getTask(null, fm, null, Arrays.asList("-source", version), null, Arrays.asList(new ToolBox.JavaSource("Test", "")));

            task.parse();

            PACK: for (String pack : packages(fm)) {

                PackageElement packEl = task.getElements().getPackageElement(pack);

                assert packEl != null;

                new ExhaustiveElementScanner(task, output, acceptor).visit(packEl);

            }

        }

    }

    Set<String> packages(JavaFileManager fm) throws IOException {

        Set<String> packages = new TreeSet<>();

        EnumSet<Kind> kinds = EnumSet.of(JavaFileObject.Kind.CLASS, JavaFileObject.Kind.OTHER);

        for (JavaFileObject file : fm.list(StandardLocation.PLATFORM_CLASS_PATH, "", kinds, true)) {

            String binary = fm.inferBinaryName(StandardLocation.PLATFORM_CLASS_PATH, file);

            packages.add(binary.substring(0, binary.lastIndexOf('.')));

        }

        return packages;

    }

    final class ExhaustiveElementScanner implements ElementVisitor<Void, Void> {

        final JavacTask task;

        final Writer out;

        final Predicate<String> acceptType;

        public ExhaustiveElementScanner(JavacTask task, Writer out, Predicate<String> acceptType) {

            this.task = task;

            this.out = out;

            this.acceptType = acceptType;

        }

        @Override

        public Void visit(Element e, Void p) {

            return e.accept(this, p);

        }

        @Override

        public Void visit(Element e) {

            return e.accept(this, null);

        }

        private void write(TypeMirror type) throws IOException {

            try {

                out.write(type.toString()

                              .replace("java.lang.invoke.MethodHandle$PolymorphicSignature", "java.lang.invoke.MethodHandle.PolymorphicSignature")

                              .replace("javax.swing.JRootPane$DefaultAction", "javax.swing.JRootPane.DefaultAction")

                              .replace("javax.swing.plaf.metal.MetalFileChooserUI$DirectoryComboBoxRenderer", "javax.swing.plaf.metal.MetalFileChooserUI.DirectoryComboBoxRenderer")

                         );

            } catch (CompletionFailure cf) {

                out.write("cf");

            }

        }

        private void writeTypes(Iterable<? extends TypeMirror> types) throws IOException {

            String sep = "";

            for (TypeMirror type : types) {

                out.write(sep);

                write(type);

                sep = ", ";

            }

        }

        private void writeAnnotations(Iterable<? extends AnnotationMirror> annotations) throws IOException {

            for (AnnotationMirror ann : annotations) {

                out.write("@");

                write(ann.getAnnotationType());

                if (!ann.getElementValues().isEmpty()) {

                    out.write("(");

                    Map<ExecutableElement, AnnotationValue> valuesMap = new TreeMap<>((a1, a2) -> a1.getSimpleName().toString().compareTo(a2.getSimpleName().toString()));

                    valuesMap.putAll(ann.getElementValues());

                    for (Entry<? extends ExecutableElement, ? extends AnnotationValue> ev : valuesMap.entrySet()) {

                        out.write(ev.getKey().getSimpleName().toString());

                        out.write(" = ");

                        out.write(ev.getValue().toString());

                    }

                    out.write(")");

                }

            }

        }

        void analyzeElement(Element e) {

            try {

                write(e.asType());

                writeAnnotations(e.getAnnotationMirrors());

                out.write(e.getKind().toString());

                out.write(e.getModifiers().toString());

                out.write(e.getSimpleName().toString());

            } catch (IOException ex) {

                ex.printStackTrace();

            }

        }

        boolean acceptAccess(Element e) {

            return e.getModifiers().contains(Modifier.PUBLIC) || e.getModifiers().contains(Modifier.PROTECTED);

        }

        @Override

        public Void visitExecutable(ExecutableElement e, Void p) {

            if (!acceptAccess(e))

                return null;

            try {

                analyzeElement(e);

                out.write(String.valueOf(e.getDefaultValue()));

                for (VariableElement param : e.getParameters()) {

                    visit(param, p);

                }

                out.write(String.valueOf(typeMirrorTranslate(e.getReceiverType())));

                write(e.getReturnType());

                out.write(e.getSimpleName().toString());

                writeTypes(e.getThrownTypes());

                for (TypeParameterElement param : e.getTypeParameters()) {

                    visit(param, p);

                }

                out.write(String.valueOf(e.isDefault()));

                out.write(String.valueOf(e.isVarArgs()));

                out.write("\n");

            } catch (IOException ex) {

                ex.printStackTrace();

            }

            return null;

        }

        /**

         * Original implementation of getReceiverType returned null

         * for many cases where TypeKind.NONE was specified; translate

         * back to null to compare against old hashes.

         */

        private TypeMirror typeMirrorTranslate(TypeMirror type) {

            if (type.getKind() == javax.lang.model.type.TypeKind.NONE)

                return null;

            else

                return type;

        }

        @Override

        public Void visitPackage(PackageElement e, Void p) {

            List<Element> types = new ArrayList<>(e.getEnclosedElements());

            Collections.sort(types, (e1, e2) -> e1.getSimpleName().toString().compareTo(e2.getSimpleName().toString()));

            for (Element encl : types) {

                visit(encl, p);

            }

            return null;

        }

        @Override

        public Void visitType(TypeElement e, Void p) {

            if (!acceptAccess(e))

                return null;

            writeType(e);

            return null;

        }

        void writeType(TypeElement e) {

            if (!acceptType.test(task.getElements().getBinaryName(e).toString()))

                return ;

            try {

                analyzeElement(e);

                writeTypes(e.getInterfaces());

                out.write(e.getNestingKind().toString());

                out.write(e.getQualifiedName().toString());

                write(e.getSuperclass());

                for (TypeParameterElement param : e.getTypeParameters()) {

                    visit(param, null);

                }

                List<Element> defs = new ArrayList<>(e.getEnclosedElements()); //XXX: forcing ordering for members - not completely correct!

                Collections.sort(defs, (e1, e2) -> e1.toString().compareTo(e2.toString()));

                for (Element def : defs) {

                    visit(def, null);

                }

                out.write("\n");

            } catch (IOException ex) {

                ex.printStackTrace();

            }

        }

        @Override

        public Void visitVariable(VariableElement e, Void p) {

            if (!acceptAccess(e))

                return null;

            try {

                analyzeElement(e);

                out.write(String.valueOf(e.getConstantValue()));

                out.write("\n");

            } catch (IOException ex) {

                ex.printStackTrace();

            }

            return null;

        }

        @Override

        public Void visitTypeParameter(TypeParameterElement e, Void p) {

            try {

                analyzeElement(e);

                out.write(e.getBounds().toString());

                out.write("\n");

            } catch (IOException ex) {

                ex.printStackTrace();

            }

            return null;

        }

        @Override

        public Void visitModule(ModuleElement e, Void p) {

            throw new IllegalStateException("Not supported yet.");

        }

        @Override

        public Void visitUnknown(Element e, Void p) {

            throw new IllegalStateException("Should not get here.");

        }

    }

    final class TestFileManager implements JavaFileManager {

        final Map<String, JavaFileObject> className2File;

        final Map<JavaFileObject, String> file2ClassName;