/*

 * Copyright (c) 2017, 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.

 */

package jdk.tools.jaotc;

import java.io.BufferedReader;

import java.io.File;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.util.stream.Stream;

final class Linker {

    private final Options options;

    private String objectFileName;

    private String libraryFileName;

    private String linkerCmd;

    String objFile() {

        return objectFileName;

    }

    String libFile() {

        return libraryFileName;

    }

    Linker(Main main) throws Exception {

        this.options = main.options;

        String name = options.outputName;

        objectFileName = name;

        libraryFileName = name;

        if (options.linkerpath != null && !(new File(options.linkerpath).exists())) {

            throw new InternalError("Invalid linker path: " + options.linkerpath);

        }

        String linkerPath;

        String linkerCheck;

        switch (options.osName) {

            case "Linux":

                if (name.endsWith(".so")) {

                    objectFileName = name.substring(0, name.length() - ".so".length());

                }

                linkerPath = (options.linkerpath != null) ? options.linkerpath : "ld";

                linkerCmd = linkerPath + " -shared -z noexecstack -o " + libraryFileName + " " + objectFileName;

                linkerCheck = linkerPath + " -v";

                break;

            case "SunOS":

                if (name.endsWith(".so")) {

                    objectFileName = name.substring(0, name.length() - ".so".length());

                }

                objectFileName = objectFileName + ".o";

                linkerPath = (options.linkerpath != null) ? options.linkerpath : "ld";

                linkerCmd = linkerPath + " -shared -o " + libraryFileName + " " + objectFileName;

                linkerCheck = linkerPath + " -V";

                break;

            case "Mac OS X":

                if (name.endsWith(".dylib")) {

                    objectFileName = name.substring(0, name.length() - ".dylib".length());

                }

                objectFileName = objectFileName + ".o";

                linkerPath = (options.linkerpath != null) ? options.linkerpath : "ld";

                linkerCmd = linkerPath + " -dylib -o " + libraryFileName + " " + objectFileName;

                linkerCheck = linkerPath + " -v";

                break;

            default:

                if (options.osName.startsWith("Windows")) {

                    if (name.endsWith(".dll")) {

                        objectFileName = name.substring(0, name.length() - ".dll".length());

                    }

                    objectFileName = objectFileName + ".obj";

                    linkerPath = (options.linkerpath != null) ? options.linkerpath : getWindowsLinkPath();

                    if (linkerPath == null) {

                        throw new InternalError("Can't locate Microsoft Visual Studio amd64 link.exe");

                    }

                    linkerCmd = linkerPath + " /DLL /OPT:NOREF /NOLOGO /NOENTRY" + " /OUT:" + libraryFileName + " " + objectFileName;

                    linkerCheck = null; // link.exe presence is verified already

                    break;

                } else {

                    throw new InternalError("Unsupported platform: " + options.osName);

                }

        }

        // Check linker presence on platforms by printing its version

        if (linkerCheck != null) {

            Process p = Runtime.getRuntime().exec(linkerCheck);

            final int exitCode = p.waitFor();

            if (exitCode != 0) {

            }

        }

    }

    void link() throws Exception {

        Process p = Runtime.getRuntime().exec(linkerCmd);

        final int exitCode = p.waitFor();

        if (exitCode != 0) {

            }

        }

        File objFile = new File(objectFileName);

        if (objFile.exists()) {

            if (!objFile.delete()) {

                throw new InternalError("Failed to delete " + objectFileName + " file");

            }

        }

        // Make non-executable for all.

        File libFile = new File(libraryFileName);

        if (libFile.exists() && !options.osName.startsWith("Windows")) {

            if (!libFile.setExecutable(false, false)) {

                throw new InternalError("Failed to change attribute for " + libraryFileName + " file");

            }

        }

    }

    /**

     * Visual Studio supported versions Search Order is: VS2013, VS2015, VS2012

     */

    public enum VSVERSIONS {

        VS2013("VS120COMNTOOLS", "C:\\Program Files (x86)\\Microsoft Visual Studio 12.0\\VC\\bin\\amd64\\link.exe"),

        VS2015("VS140COMNTOOLS", "C:\\Program Files (x86)\\Microsoft Visual Studio 14.0\\VC\\bin\\amd64\\link.exe"),

        VS2012("VS110COMNTOOLS", "C:\\Program Files (x86)\\Microsoft Visual Studio 11.0\\VC\\bin\\amd64\\link.exe");

        private final String envvariable;

        private final String wkp;

        VSVERSIONS(String envvariable, String wellknownpath) {

            this.envvariable = envvariable;

            this.wkp = wellknownpath;

        }

        String EnvVariable() {

            return envvariable;

        }

        String WellKnownPath() {

            return wkp;

        }

    }

    /**

     * Search for Visual Studio link.exe Search Order is: VS2013, VS2015, VS2012

     */

    private static String getWindowsLinkPath() {

        String link = "\\VC\\bin\\amd64\\link.exe";

        /**

         * First try searching the paths pointed to by the VS environment variables.

         */

        for (VSVERSIONS vs : VSVERSIONS.values()) {

            String vspath = System.getenv(vs.EnvVariable());

            if (vspath != null) {

                File commonTools = new File(vspath);

                File vsRoot = commonTools.getParentFile().getParentFile();

                File linkPath = new File(vsRoot, link);

                if (linkPath.exists()) {

                    return linkPath.getPath();

                }

            }

        }

        /**

         * If we didn't find via the VS environment variables, try the well known paths

         */

        for (VSVERSIONS vs : VSVERSIONS.values()) {

            String wkp = vs.WellKnownPath();

            if (new File(wkp).exists()) {

                return wkp;

            }

        }

        return null;

    }

}