/*

 * Copyright (c) 2015, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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.

 */

package build.tools.module;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.nio.charset.StandardCharsets;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.Arrays;

import java.util.Set;

import java.util.stream.Collectors;

import java.util.stream.Stream;

public class GenModuleLoaderMap {

    private static final String USAGE =

        "GenModuleLoaderMap -o <output-file> -boot m1[,m2]* -platform m3[,m4]* <original-source>";

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

        // default set of boot modules and ext modules

        Stream<String> bootModules = Stream.empty();

        Stream<String> platformModules = Stream.empty();

        Path outfile = null;

        Path source = null;

        for (int i=0; i < args.length; i++) {

            String option = args[i];

            if (option.startsWith("-")) {

                String arg = args[++i];

                if (option.equals("-boot")) {

                    String[] mns = arg.split(",");

                    bootModules = Stream.concat(bootModules, Arrays.stream(mns));

                } else if (option.equals("-platform")) {

                    String[] mns = arg.split(",");

                    platformModules = Stream.concat(platformModules, Arrays.stream(mns));

                } else if (option.equals("-o")) {

                    outfile = Paths.get(arg);

                } else {

                    throw new IllegalArgumentException("invalid option: " + option);

                }

            } else {

                source = Paths.get(option);

            }

        }

        if (outfile == null) {

            throw new IllegalArgumentException("-o must be specified");

        }

        if (Files.notExists(source)) {

            throw new IllegalArgumentException(source + " not exist");

        }

        try (BufferedWriter bw = Files.newBufferedWriter(outfile, StandardCharsets.UTF_8);

             PrintWriter writer = new PrintWriter(bw)) {

            for (String line : Files.readAllLines(source)) {

                if (line.contains("@@BOOT_MODULE_NAMES@@")) {

                    line = patch(line, "@@BOOT_MODULE_NAMES@@", bootModules);

                } else if (line.contains("@@PLATFORM_MODULE_NAMES@@")) {

                    line = patch(line, "@@PLATFORM_MODULE_NAMES@@", platformModules);

                }

                writer.println(line);

            }

        }

    }

    private static String patch(String s, String tag, Stream<String> stream) {

        String mns = stream.sorted()

            .collect(Collectors.joining("\",\n            \""));

        return s.replace(tag, mns);

    }

    /**

     * Reads the contents of the given modules file.

     */

    private static Set<String> readModuleSet(String name) throws IOException {

        try (InputStream is = GenModuleLoaderMap.class.getResourceAsStream(name);

             BufferedReader reader = new BufferedReader(new InputStreamReader(is))) {

            return reader.lines().collect(Collectors.toSet());

        }

    }

}