/*

 * Copyright (c) 2012, 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.

 */

import com.sun.source.tree.CompilationUnitTree;

import com.sun.source.tree.IdentifierTree;

import com.sun.source.tree.MemberSelectTree;

import com.sun.source.tree.Tree;

import com.sun.source.util.JavacTask;

import com.sun.source.util.Plugin;

import com.sun.source.util.TaskEvent;

import com.sun.source.util.TaskListener;

import com.sun.source.util.TreePathScanner;

import com.sun.source.util.Trees;

import java.util.regex.Pattern;

import javax.lang.model.type.TypeMirror;

import javax.tools.Diagnostic.Kind;

public class ShowTypePlugin implements Plugin {

    public String getName() {

        return "showtype";

    }

    public void call(JavacTask task, String... args) {

        Pattern pattern = null;

        if (args.length == 1)

            pattern = Pattern.compile(args[0]);

        task.addTaskListener(new PostAnalyzeTaskListener(task, pattern));

    }

    private static class PostAnalyzeTaskListener implements TaskListener {

        private final ShowTypeTreeVisitor visitor;

        PostAnalyzeTaskListener(JavacTask task, Pattern pattern) {

            visitor = new ShowTypeTreeVisitor(task, pattern);

        }

        @Override

        public void started(TaskEvent taskEvent) { }

        @Override

        public void finished(TaskEvent taskEvent) {

            if (taskEvent.getKind().equals(TaskEvent.Kind.ANALYZE)) {

                CompilationUnitTree compilationUnit = taskEvent.getCompilationUnit();

                visitor.scan(compilationUnit, null);

            }

        }

    }

    private static class ShowTypeTreeVisitor extends TreePathScanner<Void, Void> {

        private final Trees trees;

        private final Pattern pattern;

        private CompilationUnitTree currCompUnit;

        ShowTypeTreeVisitor(JavacTask task, Pattern pattern) {

            trees = Trees.instance(task);

            this.pattern = pattern;

        }

        @Override

        public Void visitCompilationUnit(CompilationUnitTree tree, Void ignore) {

            currCompUnit = tree;

            return super.visitCompilationUnit(tree, ignore);

        }

        @Override

        public Void visitIdentifier(IdentifierTree tree, Void ignore) {

            show(tree, tree.getName());

            return super.visitIdentifier(tree, ignore);

        }

        @Override

        public Void visitMemberSelect(MemberSelectTree tree, Void ignore) {

            show(tree, tree.getIdentifier());

            return super.visitMemberSelect(tree, ignore);

        }

        void show(Tree tree, CharSequence name) {

            if (pattern == null || pattern.matcher(name).matches()) {

                TypeMirror type = trees.getTypeMirror(getCurrentPath());

                trees.printMessage(Kind.NOTE, "type is " + type, tree, currCompUnit);

            }

        }

    }

}