/**

 * 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.bck2brwsr.launcher.fximpl;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.net.URL;

import java.net.URLClassLoader;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Enumeration;

import java.util.List;

import javax.script.Invocable;

import javax.script.ScriptEngine;

import javax.script.ScriptEngineManager;

import javax.script.ScriptException;

import static org.testng.Assert.*;

import org.testng.annotations.BeforeClass;

import org.testng.annotations.Test;

/**

 *

 * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 */

public class JsClassLoaderTest {

    private static ClassLoader loader;

    private static Class<?> methodClass;

    public JsClassLoaderTest() {

    }

    @BeforeClass

    public static void setUpClass() throws Exception {

        ScriptEngineManager sem = new ScriptEngineManager();

        final ScriptEngine eng = sem.getEngineByMimeType("text/javascript");

        final URL my = JsClassLoaderTest.class.getProtectionDomain().getCodeSource().getLocation();

        ClassLoader parent = JsClassLoaderTest.class.getClassLoader().getParent();

        final URLClassLoader ul = new URLClassLoader(new URL[] { my }, parent);

        loader = new JsClassLoader(parent) {

            @Override

            protected URL findResource(String name) {

                return ul.getResource(name);

            }

            @Override

            protected Fn defineFn(String code, String... names) {

                StringBuilder sb = new StringBuilder();

                sb.append("(function() {");

                sb.append("return function(");

                String sep = "";

                for (String n : names) {

                    sb.append(sep);

                    sb.append(n);

                    sep = ", ";

                }

                sb.append(") {");

                sb.append(code);

                sb.append("};");

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

                try {

                    final Object val = eng.eval(sb.toString());

                    return new Fn() {

                        @Override

                        public Object invoke(Object thiz, Object... args) throws Exception {

                            List<Object> all = new ArrayList<Object>(args.length + 1);

                            all.add(thiz == null ? val : thiz);

                            all.addAll(Arrays.asList(args));

                            Invocable inv = (Invocable)eng;

                            Object ret = inv.invokeMethod(val, "call", all.toArray());

                            return ret == val ? null : ret;

                        }

                    };

                } catch (ScriptException ex) {

                    throw new LinkageError("Can't parse: " + sb, ex);

                }

            }

            @Override

            protected Enumeration<URL> findResources(String name) {

                throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.

            }

        };

        methodClass = loader.loadClass(JsMethods.class.getName());

    }

    @Test public void noParamMethod() throws Throwable {

        Method plus = methodClass.getMethod("fortyTwo");

        try {

            final Object val = plus.invoke(null);

            assertTrue(val instanceof Number, "A number returned " + val);

            assertEquals(((Number)val).intValue(), 42);

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

    @Test public void testExecuteScript() throws Throwable {

        Method plus = methodClass.getMethod("plus", int.class, int.class);

        try {

            assertEquals(plus.invoke(null, 10, 20), 30);

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

    @Test public void overloadedMethod() throws Throwable {

        Method plus = methodClass.getMethod("plus", int.class);

        try {

            assertEquals(plus.invoke(null, 10), 10);

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

    @Test public void instanceMethod() throws Throwable {

        Method plus = methodClass.getMethod("plusInst", int.class);

        Object inst = methodClass.newInstance();

        try {

            assertEquals(plus.invoke(inst, 10), 10);

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

    @Test public void staticThis() throws Throwable {

        Method st = methodClass.getMethod("staticThis");

        try {

            assertNull(st.invoke(null));

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

    @Test public void getThis() throws Throwable {

        Object th = methodClass.newInstance();

        Method st = methodClass.getMethod("getThis");

        try {

            assertEquals(st.invoke(th), th);

        } catch (InvocationTargetException ex) {

            throw ex.getTargetException();

        }

    }

}