/*

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 * 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     8023835

 * @summary Verify that implicit type of lambda parameter is correctly attributed

 *          in Scope

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

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

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

 * @run main ScopeTest

 */

import com.sun.source.tree.CompilationUnitTree;

import com.sun.source.tree.MemberSelectTree;

import com.sun.source.tree.Scope;

import com.sun.source.util.JavacTask;

import com.sun.source.util.TreePath;

import com.sun.source.util.TreePathScanner;

import com.sun.source.util.Trees;

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

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

import com.sun.tools.javac.model.JavacTypes;

import java.io.IOException;

import java.net.URI;

import java.util.ArrayList;

import java.util.Collections;

import javax.lang.model.element.Element;

import javax.lang.model.type.TypeMirror;

import javax.lang.model.util.Types;

import javax.tools.JavaFileObject;

import javax.tools.JavaFileObject.Kind;

import javax.tools.SimpleJavaFileObject;

public class ScopeTest {

    private static final String SOURCE_CODE =

            "public class Test {\n" +

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

            "        InvokeOn f = null;\n" +

            "        f.run(x -> { x.correct(); });\n" +

            "    }\n" +

            "    public static final class FooBar {\n" +

            "        public void dontRun() { }\n" +

            "    }\n" +

            "}\n" +

            "class InvokeOn {\n" +

            "    public void run(I i) { }\n" +

            "}\n" +

            "class FooBar {\n" +

            "    public void correct() { }\n" +

            "}\n" +

            "interface I {\n" +

            "    public void run(FooBar f);\n" +

            "}";

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

        verifyLambdaScopeCorrect("");

        verifyLambdaScopeCorrect("package test;");

    }

    private static void verifyLambdaScopeCorrect(final String packageClause) throws Exception {

        JavacTool tool = JavacTool.create();

        JavaFileObject source = new SimpleJavaFileObject(URI.create("mem://Test.java"), Kind.SOURCE) {

            @Override public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {

                return packageClause + SOURCE_CODE;

            }

            @Override public boolean isNameCompatible(String simpleName, Kind kind) {

                return !"module-info".equals(simpleName);

            }

        };

        Iterable<? extends JavaFileObject> fos = Collections.singletonList(source);

        JavacTask task = tool.getTask(null, null, null, new ArrayList<String>(), null, fos);

        final Types types = JavacTypes.instance(((JavacTaskImpl) task).getContext());

        final Trees trees = Trees.instance(task);

        CompilationUnitTree cu = task.parse().iterator().next();

        task.analyze();

        new TreePathScanner<Void, Void>() {

            @Override public Void visitMemberSelect(MemberSelectTree node, Void p) {

                if (node.getIdentifier().contentEquals("correct")) {

                    TypeMirror xType = trees.getTypeMirror(new TreePath(getCurrentPath(), node.getExpression()));

                    Scope scope = trees.getScope(getCurrentPath());

                    for (Element l : scope.getLocalElements()) {

                        if (!l.getSimpleName().contentEquals("x")) continue;

                        if (!types.isSameType(xType, l.asType())) {

                            throw new IllegalStateException("Incorrect variable type in scope: " + l.asType() + "; should be: " + xType);

                        }

                    }

                }

                return super.visitMemberSelect(node, p);

            }

        }.scan(cu, null);

    }

}