/*

 * 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.

 *

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 */

/*

 * @test

 * @bug 8067422

 * @summary Check that the lambda names are not unnecessarily unstable

 * @library /tools/lib

 * @build ToolBox

 * @run main TestNonSerializableLambdaNameStability

 */

import com.sun.tools.classfile.ClassFile;

import com.sun.tools.classfile.Method;

import java.io.ByteArrayInputStream;

import java.io.InputStream;

import java.util.ArrayList;

import java.util.List;

import javax.tools.StandardLocation;

public class TestNonSerializableLambdaNameStability {

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

        new TestNonSerializableLambdaNameStability().run();

    }

    String lambdaSource = "public class L%d {\n" +

                          "    public static class A {\n" +

                          "        private Runnable r = () -> { };\n" +

                          "    }\n" +

                          "    public static class B {\n" +

                          "        private Runnable r = () -> { };\n" +

                          "    }\n" +

                          "    private Runnable r = () -> { };\n" +

                          "}\n";

    String expectedLambdaMethodName = "lambda$new$0";

    void run() throws Exception {

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

        for (int i = 0; i < 3; i++) {

            sources.add(String.format(lambdaSource, i));

        }

        ToolBox tb = new ToolBox();

        try (ToolBox.MemoryFileManager fm = new ToolBox.MemoryFileManager()) {

            tb.new JavacTask()

              .sources(sources.toArray(new String[sources.size()]))

              .fileManager(fm)

              .run();

            for (String file : fm.files.get(StandardLocation.CLASS_OUTPUT).keySet()) {

                byte[] fileBytes = fm.getFileBytes(StandardLocation.CLASS_OUTPUT, file);

                try (InputStream in = new ByteArrayInputStream(fileBytes)) {

                    boolean foundLambdaMethod = false;

                    ClassFile cf = ClassFile.read(in);

                    StringBuilder seenMethods = new StringBuilder();

                    String sep = "";

                    for (Method m : cf.methods) {

                        String methodName = m.getName(cf.constant_pool);

                        if (expectedLambdaMethodName.equals(methodName)) {

                            foundLambdaMethod = true;

                            break;

                        }

                        seenMethods.append(sep);

                        seenMethods.append(methodName);

                        sep = ", ";

                    }

                    if (!foundLambdaMethod) {

                        throw new AbstractMethodError("Did not find the lambda method, " +

                                                      "found methods: " + seenMethods.toString());

                    }

                }

            }

        }

    }

}