/*

 * 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.  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.

 */

(function () {

// Check if java.desktop module is available and we're running in non-headless mode.

// We access AWT via script to avoid direct dependency on java.desktop module.

function isHeadless() {

    var GraphicsEnvironment = java.awt.GraphicsEnvironment;

    return Java.isType(GraphicsEnvironment)? GraphicsEnvironment.isHeadless() : true;

}

// Function that shows a JFileChooser dialog and returns the file name chosen (if chosen).

// We access swing from script to avoid direct dependency on java.desktop module.

function chooseFile() {

    var JFileChooser = javax.swing.JFileChooser;

    if (!Java.isType(JFileChooser)) {

        return null;

    }

    var ExtensionFilter = javax.swing.filechooser.FileNameExtensionFilter;

    function run() {

        var chooser = new JFileChooser();

        chooser.fileFilter = new ExtensionFilter('JavaScript Files', 'js');

        var retVal = chooser.showOpenDialog(null);

        return retVal == JFileChooser.APPROVE_OPTION ?

            chooser.selectedFile.absolutePath : null;

    }

    var FutureTask = java.util.concurrent.FutureTask;

    var fileChooserTask = new FutureTask(run);

    javax.swing.SwingUtilities.invokeLater(fileChooserTask);

    return fileChooserTask.get();

}

// Function that opens up the desktop browser application with the given URI.

// We access AWT from script to avoid direct dependency on java.desktop module.

function browse(uri) {

    var Desktop = java.awt.Desktop;

    if (Java.isType(Desktop)) {

        Desktop.desktop.browse(uri);

    }

}

function printDoc(list) {

    list.forEach(function(doc) {

        print();

        print(doc.signature());

        print();

        print(doc.javadoc());

    });

}

var JShell = null;

var jshell = null;

function javadoc(obj) {

    var str = String(obj);

    if (!JShell) {

        // first time - resolve JShell class

        JShell = Packages.jdk.jshell.JShell;

        // if JShell class is available, create an instance

        jshell = Java.isType(JShell)? JShell.create() : null;

    }

    if (!jshell) {

        // we don't have jshell. Just print the default!

        return print(str);

    }

    /*

     * A java method object's String representation looks something like this:

     *

     * For an overloaded method:

     *

     *   [jdk.dynalink.beans.OverloadedDynamicMethod

     *      String java.lang.System.getProperty(String,String)

     *      String java.lang.System.getProperty(String)

     *    ]

     *

     * For a non-overloaded method:

     *

     *  [jdk.dynalink.beans.SimpleDynamicMethod void java.lang.System.exit(int)]

     *

     * jshell expects "java.lang.System.getProperty(" or "java.lang.System.exit("

     * to retrieve the javadoc comment(s) for the method.

     */

    var javaCode = str.split(" ")[2]; // stuff after second whitespace char

    javaCode = javaCode.substring(0, javaCode.indexOf('(') + 1); // strip argument types

    try {

        var analysis = jshell.sourceCodeAnalysis();

        var docList = analysis.documentation(javaCode, javaCode.length, true);

        if (!docList.isEmpty()) {

            return printDoc(docList);

        }

        /*

         * May be the method is a Java instance method. In such a case, jshell expects

         * a valid starting portion of an instance method call expression. We cast null

         * to Java object and call method on it. i.e., We pass something like this:

         *

         *  "((java.io.PrintStream)null).println("

         */

        var javaType = javaCode.substring(0, javaCode.lastIndexOf('.'));

        javaCode = "((" + javaType + ")null)" + javaCode.substring(javaCode.lastIndexOf('.'));

        docList = analysis.documentation(javaCode, javaCode.length, true);

        if (!docList.isEmpty()) {

            return printDoc(docList);

        }

    } catch (e) {

    }

    print(str);

}

return {

    isHeadless: isHeadless,

    chooseFile: chooseFile,

    browse: browse,

    javadoc: javadoc

};

})();