/**

 * 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.File;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStream;

import java.net.URL;

import java.util.Enumeration;

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;

/** Checks the basic behavior of the translator.

 *

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

 */

public class StaticMethodTest {

    @Test public void threePlusFour() throws Exception {

        assertExec(

            "Should be seven", 

            StaticMethod.class, "sum__III", 

            Double.valueOf(7), 

            3, 4

        );

    }

    @Test public void checkReallyInitializedValues() throws Exception {

        assertExec(

            "Return true", 

            StaticMethod.class, "isNull__Z", 

            Double.valueOf(1)

        );

    }

    @Test public void powerOfThree() throws Exception {

        assertExec(

            "Should be nine", 

            StaticMethod.class, "power__FF", 

            Double.valueOf(9),

            3.0f

        );

    }

    @Test public void minusOne() throws Exception {

        assertExec(

            "Should be minus one", 

            StaticMethod.class, "minusOne__I", 

            Double.valueOf(-1)

        );

    }

    @Test public void doubleWithoutLong() throws Exception {

        assertExec(

            "Should be two",

            StaticMethod.class, "minus__DDJ", 

            Double.valueOf(2),

            3.0d, 1l

        );

    }

    @Test public void divAndRound() throws Exception {

        assertExec(

            "Should be rounded to one",

            StaticMethod.class, "div__IBD", 

            Double.valueOf(1),

            3, 3.75

        );

    }

    @Test public void mixedMethodFourParams() throws Exception {

        assertExec(

            "Should be two",

            StaticMethod.class, "mix__IIJBD", 

            Double.valueOf(20),

            2, 10l, 5, 2.0

        );

    }

    @Test public void factRec() throws Exception {

        assertExec(

            "Factorial of 5 is 120",

            StaticMethod.class, "factRec__JI", 

            Double.valueOf(120),

            5

        );

    }

    @Test public void factIter() throws Exception {

        assertExec(

            "Factorial of 5 is 120",

            StaticMethod.class, "factIter__JI", 

            Double.valueOf(120),

            5

        );

    }

    @Test public void xor() throws Exception {

        assertExec(

            "Xor is 4",

            StaticMethod.class, "xor__JIJ",

            Double.valueOf(4),

            7,

            3

        );

    }

    @Test public void or() throws Exception {

        assertExec(

            "Or will be 7",

            StaticMethod.class, "orOrAnd__JZII",

            Double.valueOf(7),

            true,

            4,

            3

        );

    }

    @Test public void nullCheck() throws Exception {

        assertExec(

            "Returns nothing",

            StaticMethod.class, "none__Ljava_lang_Object_2II",

            null, 1, 3

        );

    }

    @Test public void and() throws Exception {

        assertExec(

            "And will be 3",

            StaticMethod.class, "orOrAnd__JZII",

            Double.valueOf(3),

            false,

            7,

            3

        );

    }

    @Test public void inc4() throws Exception {

        assertExec(

            "It will be 4",

            StaticMethod.class, "inc4__I",

            Double.valueOf(4)

        );

    }

    @Test public void shiftLeftInJava() throws Exception {

        int res = StaticMethod.shiftLeft(1, 8);

        assertEquals(res, 256);

    }

    @Test public void shiftLeftInJS() throws Exception {

        assertExec(

            "Setting 9th bit",

            StaticMethod.class, "shiftLeft__III",

            Double.valueOf(256),

            1, 8

        );

    }

    @Test public void shiftRightInJava() throws Exception {

        int res = StaticMethod.shiftArithmRight(-8, 3, true);

        assertEquals(res, -1);

    }

    @Test public void shiftRightInJS() throws Exception {

        assertExec(

            "Get -1",

            StaticMethod.class, "shiftArithmRight__IIIZ",

            Double.valueOf(-1),

            -8, 3, true

        );

    }

    @Test public void unsignedShiftRightInJava() throws Exception {

        int res = StaticMethod.shiftArithmRight(8, 3, false);

        assertEquals(res, 1);

    }

    @Test public void unsignedShiftRightInJS() throws Exception {

        assertExec(

            "Get -1",

            StaticMethod.class, "shiftArithmRight__IIIZ",

            Double.valueOf(1),

            8, 3, false

        );

    }

    @Test public void javaScriptBody() throws Exception {

        assertExec(

            "JavaScript string",

            StaticMethod.class, "i2s__Ljava_lang_String_2II",

            "333",

            330, 3

        );

    }

    @Test public void switchJarda() throws Exception {

        assertExec(

            "The expected value",

            StaticMethod.class, "swtch__Ljava_lang_String_2I",

            "Jarda",

            0

        );

    }

    @Test public void switchDarda() throws Exception {

        assertExec(

            "The expected value",

            StaticMethod.class, "swtch__Ljava_lang_String_2I",

            "Darda",

            1

        );

    }

    @Test public void switchParda() throws Exception {

        assertExec(

            "The expected value",

            StaticMethod.class, "swtch2__Ljava_lang_String_2I",

            "Parda",

            22

        );

    }

    @Test public void switchMarda() throws Exception {

        assertExec(

            "The expected value",

            StaticMethod.class, "swtch__Ljava_lang_String_2I",

            "Marda",

            -433

        );

    }

    private static CharSequence codeSeq;

    private static Invocable code;

    @BeforeClass 

    public void compileTheCode() throws Exception {

        StringBuilder sb = new StringBuilder();

        code = compileClass(sb, "org/apidesign/vm4brwsr/StaticMethod");

        codeSeq = sb;

    }

    private static void assertExec(

        String msg, Class clazz, String method, 

        Object expRes, Object... args

    ) throws Exception {

        assertExec(code, codeSeq, msg, clazz, method, expRes, args);

    }

    static void assertExec(

        Invocable toRun, CharSequence theCode,

        String msg, Class clazz, String method, 

        Object expRes, Object... args

    ) throws Exception {

        Object ret = null;

        try {

            ret = toRun.invokeFunction("bck2brwsr");

            ret = toRun.invokeMethod(ret, "loadClass", clazz.getName());

            ret = toRun.invokeMethod(ret, method, args);

        } catch (ScriptException ex) {

            fail("Execution failed in\n" + dumpJS(theCode), ex);

        } catch (NoSuchMethodException ex) {

            fail("Cannot find method in\n" + dumpJS(theCode), ex);

        }

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

            return;

        }

        if (expRes != null && expRes.equals(ret)) {

            return;

        }

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

    }

    static Invocable compileClass(StringBuilder sb, String... names) throws ScriptException, IOException {

        return compileClass(sb, null, names);

    }

    static Invocable compileClass(

        StringBuilder sb, ScriptEngine[] eng, String... names

    ) throws ScriptException, IOException {

        if (sb == null) {

            sb = new StringBuilder();

        }

        Bck2Brwsr.generate(sb, new EmulationResources(), names);

        ScriptEngineManager sem = new ScriptEngineManager();

        ScriptEngine js = sem.getEngineByExtension("js");

        if (eng != null) {

            eng[0] = js;

        }

        try {

            Object res = js.eval(sb.toString());

            assertTrue(js instanceof Invocable, "It is invocable object: " + res);

            return (Invocable)js;

        } catch (Exception ex) {

            if (sb.length() > 2000) {

                sb = dumpJS(sb);

            }

            fail("Could not evaluate:\n" + sb, ex);

            return null;

        }

    }

    static StringBuilder dumpJS(CharSequence sb) throws IOException {

        File f = File.createTempFile("execution", ".js");

        FileWriter w = new FileWriter(f);

        w.append(sb);

        w.close();

        return new StringBuilder(f.getPath());

    }

    private static class EmulationResources implements Bck2Brwsr.Resources {

        @Override

        public InputStream get(String name) throws IOException {

            Enumeration<URL> en = StaticMethodTest.class.getClassLoader().getResources(name);

            URL u = null;

            while (en.hasMoreElements()) {

                u = en.nextElement();

            }

            if (u == null) {

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

            }

            if (u.toExternalForm().contains("rt.jar!")) {

                throw new IOException("No emulation for " + u);

            }

            return u.openStream();

        }

    }

}