/*

 * 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

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 */

package build.tools.module;

import java.io.BufferedWriter;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Set;

/**

 * A build tool to extend the module-info.java in the source tree

 * for platform-specific exports, uses, and provides and write

 * to the specified output file.

 *

 * GenModulesList build tool currently generates the modules.list from

 * the module-info.java from the source tree that will be used for

 * the make target and dependences.

 *

 * The build currently invokes gensrc-$MODULE.gmk after modules.list

 * is generated.  Hence, platform-specific requires is not supported.

 */

public class GenModuleInfoSource {

    private final static String USAGE =

        "Usage: GenModuleInfoSource [option] -o <output file> <module-info-java>\n" +

        "Options are:\n" +

        "  -exports  <package-name>\n" +

        "  -exports  <package-name>/<module-name>\n" +

        "  -uses     <service>\n" +

        "  -provides <service>/<provider-impl-classname>\n";

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

        Path outfile = null;

        Path moduleInfoJava = null;

        Map<String, Set<String>> options = new HashMap<>();

        // validate input arguments

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

            String option = args[i];

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

                String arg = args[++i];

                if (option.equals("-exports") ||

                        option.equals("-uses") ||

                        option.equals("-provides")) {

                    options.computeIfAbsent(option, _k -> new HashSet<>()).add(arg);

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

                    outfile = Paths.get(arg);

                } else {

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

                }

            } else if (moduleInfoJava != null) {

                throw new IllegalArgumentException("more than one module-info.java");

            } else {

                moduleInfoJava = Paths.get(option);

                if (Files.notExists(moduleInfoJava)) {

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

                }

            }

        }

        if (moduleInfoJava == null || outfile == null) {

            System.err.println(USAGE);

            System.exit(-1);

        }

        // read module-info.java

        Module.Builder builder = ModuleInfoReader.builder(moduleInfoJava);

        augment(builder, options);

        // generate new module-info.java

        Module module = builder.build();

        Path parent = outfile.getParent();

        if (parent != null)

            Files.createDirectories(parent);

        try (BufferedWriter writer = Files.newBufferedWriter(outfile)) {

            writer.write(module.toString());

        }

    }

    private static void augment(Module.Builder builder, Map<String, Set<String>> options) {

        for (String opt : options.keySet()) {

            if (opt.equals("-exports")) {

                for (String arg : options.get(opt)) {

                    int index = arg.indexOf('/');

                    if (index > 0) {

                        String pn = arg.substring(0, index);

                        String mn = arg.substring(index + 1, arg.length());

                        builder.exportTo(pn, mn);

                    } else {

                        builder.export(arg);

                    }

                }

            } else if (opt.equals("-uses")) {

                options.get(opt).stream()

                        .forEach(builder::use);

            } else if (opt.equals("-provides")) {

                for (String arg : options.get(opt)) {

                    int index = arg.indexOf('/');

                    if (index <= 0) {

                        throw new IllegalArgumentException("invalid -provide argument: " + arg);

                    }

                    String service = arg.substring(0, index);

                    String impl = arg.substring(index + 1, arg.length());

                    builder.provide(service, impl);

                }

            }

        }

    }

}