/*

 * 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.

 */

// Usage: jjs javacastcounter.js -- <.java files>

// This example demonstrates Nashorn Java.extend API

// to subclass a Java class from script.

// This example uses Javac Compiler and Tree API

// to list type casts used in java source files.

if (arguments.length == 0) {

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

    exit(1);

}

// Java types used

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

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

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

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

// 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(arguments, StringArray));

// create a new compilation task

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

// SourcePositions object to get positions of AST nodes

var sourcePositions = Trees.instance(task).sourcePositions;

// Subclass TreeScanner class

var CastCounter = Java.extend(TreeScanner);

var counter = new CastCounter() {

    // current CompilationUnitTree

    compUnit: null,

    // current LineMap (pos -> line, column)

    lineMap: null,

    // current compilation unit's file name

    fileName: null,

    // overrides of TreeScanner methods

    visitCompilationUnit: function(node, p) {

        // capture info about current Compilation unit

        this.compUnit = node;

        this.lineMap = node.lineMap;

        this.fileName = node.sourceFile.name;

        // Using Java.super API to call super class method here        

        return Java.super(counter).visitCompilationUnit(node, p);

    },

    visitTypeCast: function(node, p) {

        // print information on this type cast node

        var pos = sourcePositions.getStartPosition(this.compUnit, node);

        var line = this.lineMap.getLineNumber(pos);

        var col = this.lineMap.getColumnNumber(pos);

        print(node + " @ " + this.fileName + ":" + line + ":" + col);

        // count one more type cast

        return 1;

    },

    reduce: function(r1, r2) {

        return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);

    }

};

// print total number of type cast nodes seen

print("Total casts:", counter.scan(task.parse(), null));