//You need this to allow methods that can be invoked by Java
#include <jni.h>

//This syntax is needed if you are invoking a C++ method. C methods are slightly different

//Since the String method returns a String object, specify jstring. Replace this with whatever return object your method has.

extern "C" JNIEXPORT jstring JNICALL
//Replace the crazy ass method name with the path to the Java file that is invoking it (com/example/NativeLib in this case).

//The Native Methods must always have JNIEnv *env, jobject object as the first two parameters
Java_com_example_NativeLib_string(JNIEnv *env, jobject object) {
    //This is how you return a jstring via C++ code
    return env->NewStringUTF("Hello from JNI LIBS!");
}

// C syntax: my package name is com.autodesk.and.jnitester
// and my activity invoking the native method is MainActivity,
// hence the name of my method is
//Java_com_autodesk_and_jnitester_MainActivity_MethodName
JNIEXPORT
jstring
JNICALL
Java_com_autodesk_adn_jnitester_MainActivity_getMessageFromNative(
    JNIEnv *env,
    jobject callingObject)
{
    return (*env)->NewStringUTF(env, "Native code rules!");
}


// C++ syntax: Required to declare as extern "C" to prevent c++ compiler
// to mangle function names
extern "C"
{
     JNIEXPORT
     jstring
     JNICALL
     Java_com_autodesk_adn_jnitester_MainActivity_getMessageFromNative(
                JNIEnv *env,
                jobject callingObject)
     {
           return env->NewStringUTF("Native code rules!");
     }
};

JNIEXPORT
jfloat
JNICALL
Java_com_autodesk_adn_jnitester_MainActivity_getMemberFieldFromNative
(
	JNIEnv *env,
	jobject callingObject,
	jobject obj //obj is the MeshData java object passed
) 
{
   float result = 0.0f;
 
   //Get the passed object's class  
   jclass cls = env->GetObjectClass(obj);
 
   // get field [F = Array of float
   jfieldID fieldId = env->GetFieldID(cls, "VertexCoords", "[F");
 
   // Get the object field, returns JObject (because it’s an Array)
   jobject objArray = env->GetObjectField (obj, fieldId);
 
   // Cast it to a jfloatarray
   jfloatArray* fArray = reinterpret_cast<jfloatArray*>(&objArray);
 
   jsize len = env->GetArrayLength(*fArray);
 
   // Get the elements
   float* data = env->GetFloatArrayElements(*fArray, 0);
 
   for(int i=0; i<len; ++i)
   {
        result += data[i];
   }
 
   // Don't forget to release it
   env->ReleaseFloatArrayElements(*fArray, data, 0);
 
   return result;
}

JNIEXPORT
jint
JNICALL     
Java_com_autodesk_adn_jnitester_MainActivity_invokeMemberFuncFromNative
(
	JNIEnv *env,
	jobject callingObject,
	jobject obj
)
{
	jclass cls = env->GetObjectClass(obj);
	jmethodID methodId = env->GetMethodID(cls, "getFacetCount", "()I");
	int result = env->CallIntMethod(obj, methodId);
	    
	//Return the facet count (an int)  
	return result;
}

JNIEXPORT
jobject
JNICALL
Java_com_autodesk_adn_jnitester_MainActivity_createObjectFromNative
(
	JNIEnv *env,
	jobject callingObject,
	jint param
)
{
	jclass cls = env->FindClass("com/autodesk/adn/jnitester/MeshData");
	jmethodID methodId = env->GetMethodID(cls, "<init>", "(I)V");
	jobject obj = env->NewObject(cls, methodId, param);
 
	return obj;
}

JNIEXPORT
jint
JNICALL
Java_com_autodesk_adn_jnitester_MainActivity_processObjectArrayFromNative
(
	JNIEnv *env,
	jobject callingObject,
	jobjectArray objArray
)
{
	int resultSum = 0;
	 
	int len = env->GetArrayLength(objArray);
	 
	//Get all the objects in the array
	for(int i=0; i<len; ++i)
	{
	    jobject obj = (jobject) env->GetObjectArrayElement(objArray, i);
	 
	    resultSum += getFacetCount(env, obj);
	}
	 
	return resultSum;
}

JNIEXPORT 
jobjectArray 
JNICALL 
Java_ProcessInformation_getAllProcessPid
(
	JNIEnv*env,
	jobject obj
)
{
	//Create a vector (an array) of Strings and add items to it
   vector<string>vec;
	vec.push_back("Ranjan.B.M");
	vec.push_back("Mithun.V");
	vec.push_back("Preetham.S.N");
	vec.push_back("Karthik.S.G");
	cout<< vec[0];

	//Instantiate your object Array and return it!
	jclass clazz = (env)->FindClass("java/lang/String");
	jobjectArray objarray = (env)->NewObjectArray(vec.size() ,clazz ,0);
	for(int i=0; i < vec.size(); i++) {
		string s = vec[i];
		cout<< vec[i] <<endl;
		jstring js = (env)->NewStringUTF(s.c_str());
		(env)->SetObjectArrayElement(objarray, i, js);
	}
	return objarray;
}