/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 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.vm4brwsr;

import com.google.javascript.jscomp.CommandLineRunner;

import com.google.javascript.jscomp.SourceFile;

import java.io.IOException;

import java.io.OutputStream;

import java.io.PrintStream;

import java.util.Collections;

import java.util.List;

import org.apidesign.bck2brwsr.core.ExtraJavaScript;

/**

 *

 * @author Jaroslav Tulach <jtulach@netbeans.org>

 */

@ExtraJavaScript(processByteCode = false, resource="")

final class ClosureWrapper extends CommandLineRunner implements SourceFile.Generator {

    private static final String[] ARGS = { "--compilation_level", "SIMPLE_OPTIMIZATIONS", "--js", "bck2brwsr-raw.js" };

    private String code;

    private final Bck2Brwsr.Resources res;

    private final StringArray classes;

    private ClosureWrapper(Appendable out, ObfuscationLevel obfuscationLevel,

                           Bck2Brwsr.Resources res, StringArray classes) {

        super(

            generateArguments(obfuscationLevel),

            new PrintStream(new APS(out)), System.err

        );

        this.res = res;

        this.classes = classes;

    }

    @Override

    protected List<SourceFile> createInputs(List<String> files, boolean allowStdIn) throws FlagUsageException, IOException {

        if (files.size() != 1 || !"bck2brwsr-raw.js".equals(files.get(0))) {

            throw new IOException("Unexpected files: " + files);

        }

        return Collections.nCopies(1, SourceFile.fromGenerator("bck2brwsr-raw.js", this));

    }

    @Override

    public String getCode() {

        if (code == null) {

            StringBuilder sb = new StringBuilder();

            try {

                VM.compile(res, sb, classes);

            } catch (IOException ex) {

                code = ex.getMessage();

            }

            code = sb.toString();

        }

        return code;

    }

    private static final class APS extends OutputStream {

        private final Appendable out;

        public APS(Appendable out) {

            this.out = out;

        }

        @Override

        public void write(int b) throws IOException {

            out.append((char)b);

        }

    }

    private static String[] generateArguments(

            ObfuscationLevel obfuscationLevel) {

        String[] finalArgs = ARGS.clone();

        finalArgs[1] = obfuscationLevel.toString();

        return finalArgs;

    }

    static int produceTo(Appendable w, ObfuscationLevel obfuscationLevel, Bck2Brwsr.Resources resources, StringArray arr) throws IOException {

        ClosureWrapper cw = new ClosureWrapper(w, obfuscationLevel, resources,

                                               arr);

        try {

            return cw.doRun();

        } catch (FlagUsageException ex) {

            throw new IOException(ex);

        }

    }

}