/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program 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 for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.vm4brwsr;

 import java.io.IOException;

 import java.io.InputStream;

 import javax.script.Invocable;

 import javax.script.ScriptContext;

 import javax.script.ScriptEngine;

 import javax.script.ScriptException;

 import org.testng.annotations.BeforeClass;

 import static org.testng.Assert.*;

 import org.testng.annotations.Test;

 /** Implements loading class by class.

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 public class VMLazyTest {

     private static CharSequence codeSeq;

     private static Invocable code;

     @BeforeClass

     public void compileTheCode() throws Exception {

         StringBuilder sb = new StringBuilder();

         sb.append("\nfunction test(clazz, as, method) {");

         sb.append("\n  var l = new lazyVM();");

         sb.append("\n  var c = l.loadClass(clazz, as);");

         sb.append("\n  return c[method]();");

         sb.append("\n}");

         sb.append("\nfunction lazyVM() {");

         sb.append("\n  var self = this;");

         sb.append("\n  this.constructor.prototype.Identity = function(value) {");

         sb.append("\n    var self = this;");

         sb.append("\n    self.value = value;");

         sb.append("\n    self.call = function() { return self.value; };");

         sb.append("\n  };");

         sb.append("\n");

         sb.append("\n  this.constructor.prototype.loadClass = function(res, name) {");

         sb.append("\n    var script = org_apidesign_vm4brwsr_VMLazy_toJavaScriptLjava_lang_StringAB(loader.get(res + '.class'));");

         sb.append("\n    try {");

         sb.append("\n      new Function(");

         sb.append("\n        'arguments[0][arguments[1]]=new lazyVM.prototype.Identity(' + script + ').call'");

         sb.append("\n      )(self, name);");

         sb.append("\n    } catch (ex) {");

         sb.append("\n      throw 'Cannot compile ' + res + ' error: ' + ex + ' script:\\n' + script;");

         sb.append("\n    };");

         sb.append("\n  };");

         sb.append("\n");

         sb.append("\n}\n");

         ScriptEngine[] arr = { null };

         code = StaticMethodTest.compileClass(sb, arr,

             "org/apidesign/vm4brwsr/VMLazy"

         );

         arr[0].getContext().setAttribute("loader", new FindBytes(), ScriptContext.ENGINE_SCOPE);

         codeSeq = sb;

     }

     @Test public void invokeStaticMethod() throws Exception {

         assertExec("Trying to get -1", "test", Double.valueOf(-1),

             "org/apidesign/vm4brwsr/StaticMethod", "org_apidesign_vm4brwsr_StaticMethod", "minusOne"

         );

     }

     private static void assertExec(String msg, String methodName, Object expRes, Object... args) throws Exception {

         Object ret = null;

         try {

             ret = code.invokeFunction(methodName, args);

         } catch (ScriptException ex) {

             fail("Execution failed in\n" + StaticMethodTest.dumpJS(codeSeq), ex);

         } catch (NoSuchMethodException ex) {

             fail("Cannot find method in\n" + StaticMethodTest.dumpJS(codeSeq), ex);

         }

         if (ret == null && expRes == null) {

             return;

         }

         if (expRes.equals(ret)) {

             return;

         }

         assertEquals(ret, expRes, msg + "was: " + ret + "\n" + codeSeq);

     }

     public static final class FindBytes {

         public byte[] get(String name) throws IOException {

             InputStream is = VMLazyTest.class.getClassLoader().getResourceAsStream(name);

             if (is == null) {

                 throw new IOException("Can't find " + name);

             }

             byte[] arr = new byte[is.available()];

             int len = is.read(arr);

             if (len != arr.length) {

                 throw new IOException("Read only " + len + " wanting " + arr.length);

             }

             System.err.print("loader['" + name + "'] = [");

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

                 if (i > 0) {

                     System.err.print(", ");

                 }

                 System.err.print(arr[i]);

             }

             System.err.println("]");

             return arr;

         }

     }

 }