#// Usage: jjs -fx javaastviewer.js -- <.java files>

/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

 * 

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 

 *   - Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 * 

 *   - Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 * 

 *   - Neither the name of Oracle nor the names of its

 *     contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS

 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

// This example demonstrates Java subclassing by Java.extend

// and javac Compiler and Tree API. This example also uses

// -fx and javafx TreeView to visualize Java AST as TreeView

if (!$OPTIONS._fx || arguments.length == 0) {

    print("Usage: jjs -fx javaastviewer.js -- <.java files>");

    exit(1);

}

// Java types used

var Enum = Java.type("java.lang.Enum");

var HashSet  = Java.type("java.util.HashSet");

var Name = Java.type("javax.lang.model.element.Name");

var List = Java.type("java.util.List");

var Set  = Java.type("java.util.Set");

var SimpleTreeVisitor = Java.type("com.sun.source.util.SimpleTreeVisitor");

var StringArray = Java.type("java.lang.String[]");

var ToolProvider = Java.type("javax.tools.ToolProvider");

var Tree = Java.type("com.sun.source.tree.Tree");

function javaASTToScriptObject(args) {

    // properties ignored (javac implementation class properties) in AST view.

    // may not be exhaustive - any getAbc would become "abc" property or

    // public field becomes a property of same name.

    var ignoredProps = new HashSet();

    for each (var word in 

        ['extending', 'implementing', 'init', 'mods', 'clazz', 'defs', 

         'expr', 'tag', 'preferredPosition', 'qualid', 'recvparam',

         'restype', 'params', 'startPosition', 'thrown',

         'tree', 'typarams', 'typetag', 'vartype']) {

        ignoredProps.add(word);

    }

    // get the system compiler tool

    var compiler = ToolProvider.systemJavaCompiler;

    // get standard file manager

    var fileMgr = compiler.getStandardFileManager(null, null, null);

    // make a list of compilation unit from command line argument file names

    // Using Java.to convert script array (arguments) to a Java String[]

    var compUnits = fileMgr.getJavaFileObjects(Java.to(args, StringArray));

    // create a new compilation task

    var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);

    // subclass SimpleTreeVisitor - converts Java AST node to

    // a simple script object by walking through it

    var ConverterVisitor = Java.extend(SimpleTreeVisitor);

    var visitor = new ConverterVisitor() {

        // convert java AST node to a friendly script object

        // which can be viewed. Every node ends up in defaultAction 

        // method of SimpleTreeVisitor method.

        defaultAction: function (node, p) {

            var resultObj = {};

            // Nashorn does not iterate properties and methods of Java objects

            // But, we can bind properties of any object (including java objects)

            // to a script object and iterate it!

            var obj = {};

            Object.bindProperties(obj, node);

            // we don't want every property, method of java object

            for (var prop in obj) {

                var val = obj[prop];

                var type = typeof val;

                // ignore 'method' members

                if (type == 'function' || type == 'undefined') {

                    continue;

                }

                // ignore properties from Javac implementation

                // classes - hack by name!!

                if (ignoredProps.contains(prop)) {

                    continue;

                }

                // subtree - recurse it

                if (val instanceof Tree) {

                    resultObj[prop] = visitor.visit(val, p);

                } else if (val instanceof List) {

                    // List of trees - recurse each and make an array

                    var len = val.size();

                    if (len != 0) {

                        var arr = [];

                        for (var j = 0; j < len; j++) {

                            var e = val[j];

                            if (e instanceof Tree) {

                                arr.push(visitor.visit(e, p));

                            }

                        }

                        resultObj[prop] = arr;

                    }

                } else if (val instanceof Set) {

                    // Set - used for modifier flags

                    // make array

                    var len = val.size();

                    if (len != 0) {

                        var arr = [];

                        for each (var e in val) {

                            if (e instanceof Enum || typeof e == 'string') {

                                arr.push(e.toString());

                            }

                        }

                        resultObj[prop] = arr;

                    }

                } else if (val instanceof Enum || val instanceof Name) {

                    // make string for any Enum or Name

                    resultObj[prop] = val.toString();

                } else if (type != 'object') {

                    // primitives 'as is'

                    resultObj[prop] = val;

                }

            }

            return resultObj;

        }

    }

    // top level object with one property for each compilation unit

    var scriptObj = {};

    for each (var cu in task.parse()) {

        scriptObj[cu.sourceFile.name] = cu.accept(visitor, null);

    }

    return scriptObj;

}

// JavaFX classes used

var StackPane = Java.type("javafx.scene.layout.StackPane");

var Scene     = Java.type("javafx.scene.Scene");

var TreeItem  = Java.type("javafx.scene.control.TreeItem");

var TreeView  = Java.type("javafx.scene.control.TreeView");

// Create a javafx TreeItem to view a script object

function treeItemForObject(obj, name) {

    var item = new TreeItem(name);

    for (var prop in obj) {

       var node = obj[prop];

       if (typeof node == 'object') {

           if (node == null) {

               // skip nulls

               continue;

           }

           var subitem = treeItemForObject(node, prop);

       } else {

           var subitem = new TreeItem(prop + ": " + node);

       }

       item.children.add(subitem);

    }

    item.expanded = true;

    return item;

}

var commandArgs = arguments;

// JavaFX start method

function start(stage) {

    var obj = javaASTToScriptObject(commandArgs);

    stage.title = "Java AST Viewer"

    var rootItem = treeItemForObject(obj, "AST");

    rootItem.expanded = true;

    var tree = new TreeView(rootItem);

    var root = new StackPane();

    root.children.add(tree);

    stage.scene = new Scene(root, 300, 450);

    stage.show();

}