/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012-2015 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 2 of the License.

 *

 * This program 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 for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.bck2brwsr.flow;

import java.util.Arrays;

import org.apidesign.vm4brwsr.Bck2Brwsr;

/** Poweful flow analyzer. Based on internals used by Graal JVM

 * compiler.

 *

 * @author Jaroslav Tulach

 */

public final class GraalFlowAnalyzer {

    private GraalFlowAnalyzer() {

    }

    public static Bck2Brwsr.Flow.Analyzer getDefault() {

        return Impl.DEFAULT;

    }

    private static class Impl implements Bck2Brwsr.Flow.Analyzer {

        static Impl DEFAULT = new Impl();

        private Impl() {

        }

        @Override

        public boolean analyze(final Bck2Brwsr.Flow result) {

            /*

            // Delete the previous line and fix pom.xml, David.

            try {

                new com.oracle.graal.tag.codegen.BCCodeGenerator(

                    com.oracle.graal.tag.BCTagDriver.tagGraph(result.getMethodByteCode())

                ) {

                    @Override

                    protected void emitIfStart(int bci, String txt) {

                        System.err.println("if { // " + bci);

                        result.beginIfAt(bci);

                    }

                    @Override

                    protected void emitEnd(int bci) {

                        System.err.println("} // " + bci);

                        result.endAt(bci);

                    }

                    @Override

                    protected void emitElseHeader(int bci) {

                        System.err.println("else { //" + bci);

                        result.beginElseAt(bci);

                    }

                    @Override

                    protected void emitLoopHeader(int bci) {

                        System.err.println("for (;;) { // " + bci);

                        result.beginLoopAt(bci);

                    }

                    @Override

                    protected void emitBreak(int bci) {

                        System.err.println("break; // " + bci);

                        result.breakAt(bci);

                    }

                    @Override

                    protected void emit(String txt) {

                    }

                }.GenBCCode();

                return true;

            } catch (Exception e) {

                e.printStackTrace();

            }

            // */

            byte[] simpleLoopTestMock = { 3, 60, 3, 61, 28, 26, -94, 0, 13, 27, 28, 96, 60, -124, 2, 1, -89, -1, -12, 27, 26, 104, -84 };

            if (Arrays.equals(

                simpleLoopTestMock,

                result.getMethodByteCode()

            )) {

                result.beginLoopAt(4); // for (;;) { // 4

                result.beginIfAt(6); // if { // 6

                result.breakAt(9); // ;break; // 9

                result.endAt(9); // ;} // 9

                result.beginElseAt(9); // else { //9

                result.endAt(19); // } // 19

                result.endAt(19); // } // 19

                return true;

            }

            return false;

        }

    }

}