/***************************************************************************
 * jvminterpreter.cpp
 * This file is part of the KDE project
 *
 * copyright (C)2007 by Vincent Verhoeven <verhoevenv@gmail.com>
 * copyright (C)2007 by Sebastian Sauer <mail@dipe.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 * 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
 * Library General Public License for more details.
 * You should have received a copy of the GNU Library General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 ***************************************************************************/

#include "jvminterpreter.h"
#include "jvmscript.h"
#include "jvmvariant.h"
#include "jvmextension.h"

#include <kross/core/action.h>
#include <kross/core/manager.h>

#include <kglobal.h>
#include <kstandarddirs.h>

#include <QVarLengthArray>

#ifdef Q_WS_WIN
    #define KROSS_JVM_PATHSEPARATOR ';'
#else
    #define KROSS_JVM_PATHSEPARATOR ':'
#endif

// The in krossconfig.h defined KROSS_EXPORT_INTERPRETER macro defines an
// exported C function used as factory for Kross::JVMInterpreter instances.
KROSS_EXPORT_INTERPRETER( Kross::JVMInterpreter )

using namespace Kross;

namespace Kross {

//TODO: search some fine place for this.
jobject JNICALL callQMethod(JNIEnv *env, jobject self, jlong p, jstring method,
  jint argc, jobject arg0, jobject arg1, jobject arg2, jobject arg3, jobject arg4,
  jobject arg5, jobject arg6, jobject arg7, jobject arg8, jobject arg9)
{
    Q_UNUSED(self);

    JVMExtension* obj = static_cast<JVMExtension*>(JavaType<void*>::toVariant(p,env));

    int numargs = argc;
    QVarLengthArray<jobject, 8> args(numargs);

    switch(numargs) {
        case 10:
            args[9] = arg9; //all this is fallthrough
        case 9:
            args[8] = arg8;
        case 8:
            args[7] = arg7;
        case 7:
            args[6] = arg6;
        case 6:
            args[5] = arg5;
        case 5:
            args[4] = arg4;
        case 4:
            args[3] = arg3;
        case 3:
            args[2] = arg2;
        case 2:
            args[1] = arg1;
        case 1:
            args[0] = arg0;
    }

    return obj->callQMethod(env, method, numargs, args.data());
}

jboolean JNICALL callConnect(JNIEnv *env, jobject self, jlong jvmsender, jstring signal, jobject receiver, jobject method)
{
    Q_UNUSED(self);

    JVMExtension* obj = static_cast<JVMExtension*>(JavaType<void*>::toVariant(jvmsender,env));

    return obj->doConnect(env, signal, receiver, method);
}

    /// \internal
    class JVMInterpreter::Private
    {
        public:
            JNIEnv *env;
            JavaVM *jvm;
            JavaVMInitArgs vm_args;
            jobject classloader;
            jclass clclass;

            //List of running JVMExtensions we know about, indexed with the wrapped QObject*
            QHash<const QObject*, const JVMExtension*> runningExtensions;

            jmethodID addclass;
            jmethodID newinst;
            jmethodID addurl;
            jmethodID addextension;

            explicit Private() : env(0), jvm(0), classloader(0), addclass(0), addurl(0) {
                vm_args.version  = JNI_VERSION_1_2; /* Specifies the JNI version used */
                vm_args.ignoreUnrecognized = JNI_TRUE; /* JNI won't complain about unrecognized options */
            }
            bool initialize() {
                #ifdef KROSS_JVM_INTERPRETER_DEBUG
                    krossdebug("JVMInterpreter initialize");
                #endif
                jint res = JNI_CreateJavaVM( &jvm, (void **)&env, &vm_args );
                if(res < 0)
                    return false;

                //Create classloader
                jclass clclass = env->FindClass( "org/kde/kdebindings/java/krossjava/KrossClassLoader" );
                if (clclass == 0) {
                  krosswarning( "Class 'KrossClassLoader' not found! Is kross.jar accessible?" );
                  return false;
                }
                addclass = env->GetMethodID(clclass, "addClass", "(Ljava/lang/String;[B)Ljava/lang/String;");
                newinst = env->GetMethodID(clclass, "newInstance", "(Ljava/lang/String;)Ljava/lang/Object;");
                addurl = env->GetMethodID(clclass, "addURL", "(Ljava/net/URL;)V");
                addextension = env->GetMethodID(clclass, "addExtension", "(Ljava/lang/String;J)Lorg/kde/kdebindings/java/krossjava/KrossQExtension;");
                if (addclass == 0 || newinst == 0 || addurl == 0 || addextension == 0) {
                  krosswarning("Classloader method not found!");
                  return false;
                }
                jmethodID ctor = env->GetMethodID(clclass, "<init>", "()V");
                if (ctor == 0) {
                  krosswarning("Classloader constructor not found!");
                  return false;
                }
                jobject loaderweak = env->NewObject(clclass, ctor);
                if (loaderweak == 0) {
                  krosswarning("Could not create classloader!");
                  return false;
                }
                classloader = env->NewGlobalRef(loaderweak);

                jclass proxy = env->FindClass("org/kde/kdebindings/java/krossjava/KrossQExtension");
                JNINativeMethod nativeMethod[2];
                nativeMethod[0].name = "invokeNative";
                nativeMethod[0].signature = "(JLjava/lang/String;ILjava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;"
                                          "Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;"
                                          "Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;";
                nativeMethod[0].fnPtr = (void*) callQMethod;
                nativeMethod[1].name = "connect";
                nativeMethod[1].signature = "(JLjava/lang/String;Ljava/lang/Object;Ljava/lang/reflect/Method;)Z";
                nativeMethod[1].fnPtr = (void*) callConnect;
                env->RegisterNatives(proxy, nativeMethod, 2);

                handleException();

                return true;
            }
            bool finalize() {
                jint res = jvm->DestroyJavaVM();
                //return ( ! env->ExceptionOccurred() );
                //Note, this will always fail according to DestroyJavaVM specification
                return res >= 0;
            }
    };

}

JVMInterpreter::Private* const JVMInterpreter::d = new JVMInterpreter::Private();

JVMInterpreter::JVMInterpreter(InterpreterInfo* info)
    : Interpreter(info)
{
    #ifdef KROSS_JVM_INTERPRETER_DEBUG
        krossdebug("JVMInterpreter Ctor");
    #endif

    //Construct classpath
    QString cp = "-Djava.class.path=";
    //Add kross.jar
    QString jarlocation = KGlobal::dirs()->findResource("module", "kross/kross.jar");
    if(jarlocation.isNull()){
        krosswarning("kross.jar not found!");
    }
    cp += jarlocation;
    //Add other dirs - probably use KGlobal::dirs() here too?
    cp += KROSS_JVM_PATHSEPARATOR;
    cp += '.';
    cp += KROSS_JVM_PATHSEPARATOR;
    cp += "/myClassDir";
    QByteArray ba( cp.toAscii() );

    JavaVMOption    options[2];
    options[0].optionString = ba.data();
    options[1].optionString = "-Djava.library.path=.:/myLibDir";
    d->vm_args.options  = options;
    d->vm_args.nOptions = 2;

    if( ! d->initialize() ) {
        krosswarning("JVMInterpreter Ctor: Failed to initialize");
    }
}

JVMInterpreter::~JVMInterpreter()
{
    #ifdef KROSS_JVM_INTERPRETER_DEBUG
        krossdebug("JVMInterpreter Dtor");
    #endif
    if( ! d->finalize() ) {
        krosswarning("JVMInterpreter Dtor: Failed to finalize");
    }
    delete d;
}


Script* JVMInterpreter::createScript(Action* action)
{
    return new JVMScript(this, action);
}

JNIEnv* JVMInterpreter::getEnv()
{
    JNIEnv* m_env;
    d->jvm->GetEnv((void**)&m_env,JNI_VERSION_1_2);
    return m_env;
}

JavaVM* JVMInterpreter::getJVM()
{
    return d->jvm;
}

void JVMInterpreter::addToCP(const QUrl& url)
{
    Q_ASSERT(d->classloader);
    jobject jurl = JavaType<QUrl>::toJObject(url,d->env);
    d->env->CallVoidMethod(d->classloader,d->addurl,jurl);

    handleException();
}

QString JVMInterpreter::addClass(const QString& name, const QByteArray& array)
{
    jstring jname = JavaType<QString>::toJObject(name,d->env);
    jbyteArray jarray = JavaType<QByteArray>::toJObject(array,d->env);
    jobject realName = d->env->CallObjectMethod(d->classloader,d->addclass,jname,jarray);

    handleException();

    return JavaType<QString>::toVariant(realName, d->env);
}

jobject JVMInterpreter::addExtension(const QString& name, const JVMExtension* obj, const QByteArray& clazz, const QObject* wrapped){
    addClass(name, clazz);

    jstring jname = JavaType<QString>::toJObject(name,d->env);
    jlong pointer = JavaType<void*>::toJObject(obj,d->env);
    jobject jobj = d->env->CallObjectMethod(d->classloader,d->addextension,jname,pointer);

    handleException();

    d->runningExtensions.insert(wrapped, obj);

    return jobj;
}

const JVMExtension* JVMInterpreter::extension(const QObject* obj){
    return d->runningExtensions.value(obj);
}

//TODO: a way to add arguments? Would be hard though.
jobject JVMInterpreter::newObject(const QString& fullname)
{
    jstring jname = JavaType<QString>::toJObject(fullname,d->env);
    jobject obj = d->env->CallObjectMethod(d->classloader,d->newinst,jname);

    if(handleException()){
        return 0;
    }
    return obj;
}

bool JVMInterpreter::handleException()
{
    if(/*jthrowable exc = */d->env->ExceptionOccurred()){
        //TODO: do this with krosswarning()
        d->env->ExceptionDescribe();
        d->env->ExceptionClear();
        return true;
    }

    return false;
}

#ifdef KROSS_JVM_INTERPRETER_DEBUG
void JVMInterpreter::showDebugInfo(jobject obj)
{
    if(obj == NULL){
        krossdebug("Object is NULL!");
        return;
    }
    JNIEnv* env = d->env;
    jclass objectcl = env->FindClass("java/lang/Object");
    jclass classcl = env->FindClass("java/lang/Class");
    jmethodID getclass = env->GetMethodID(objectcl, "getClass", "()Ljava/lang/Class;");
    jmethodID getname = env->GetMethodID(classcl, "getName", "()Ljava/lang/String;");
    jmethodID tostr = env->GetMethodID(objectcl, "toString", "()Ljava/lang/String;");
    jobject classobj = env->CallObjectMethod(obj, getclass);
    jobject classname = env->CallObjectMethod(classobj, getname);
    jobject objectstring = env->CallObjectMethod(obj, tostr);

    krossdebug(QString("Object stringified: %1").arg(JavaType<QString>::toVariant(objectstring, env)) );
    krossdebug(QString("Object is of class: %1").arg(JavaType<QString>::toVariant(classname, env)) );
}
#endif