/*

 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include "jni.h"

//Method to verify expression and throw java/lang/Exception if it is FALSE

void Assert(JNIEnv *jni_env, jint expr, const char* message) {

    if(expr == 0){ //if expr is false

        (*jni_env)->FatalError(jni_env, message);

    }

}

//Method to allocate a java/lang/String object and return jstring as a result

jstring AllocateString(JNIEnv *jni_env) {

    jclass classString = NULL;

    jstring allocatedString = NULL;

    classString = (*jni_env)->FindClass(jni_env, "java/lang/String");

    //NULL check

    Assert(jni_env, (classString != NULL), "class String not found");

    //allocate object of type java/lang/String

    allocatedString = (jstring) (*jni_env)->AllocObject(jni_env, classString);

    //NULL check

    Assert(jni_env, (allocatedString != NULL), "allocated string is NULL");

    return allocatedString;

}

//GetStringLength test

JNIEXPORT void JNICALL Java_UninitializedStrings_lengthTest

(JNIEnv *jni_env, jclass cl) {

    jint stringLength = 0;

    jstring allocatedString = NULL;

    //allocate object of type java/lang/String

    allocatedString = AllocateString(jni_env);

    stringLength = (*jni_env)->GetStringLength(jni_env, allocatedString);

    Assert(jni_env, (stringLength == 0), "string length must be 0");

}

//GetStringChars test

JNIEXPORT void JNICALL Java_UninitializedStrings_charsTest

(JNIEnv *jni_env, jclass cl) {

    jint compareRes = 0;

    const jchar* stringChars = NULL;

    jstring allocatedString = NULL;

    //allocate object of type java/lang/String

    allocatedString = AllocateString(jni_env);

    stringChars = (*jni_env)->GetStringChars(jni_env, allocatedString, NULL);

    compareRes = (stringChars == NULL);

    //release stringChars pointer

    (*jni_env)->ReleaseStringChars(jni_env, allocatedString, stringChars);

    Assert(jni_env, compareRes, "string chars must be NULL");

}

//GetStringUTFLength test

JNIEXPORT void JNICALL Java_UninitializedStrings_utfLengthTest

(JNIEnv *jni_env, jclass cl) {

    jint stringLength = 0;

    jstring allocatedString = NULL;

    //allocate object of type java/lang/String

    allocatedString = AllocateString(jni_env);

    stringLength = (*jni_env)->GetStringUTFLength(jni_env, allocatedString);

    Assert(jni_env, (stringLength == 0), "string utf length must be 0");

}

//GetStringUTFChars test

JNIEXPORT void JNICALL Java_UninitializedStrings_utfCharsTest

(JNIEnv *jni_env, jclass cl) {

    jint compareRes = 0;

    const char* stringUtfChars = NULL;

    jstring allocatedString = NULL;

    //allocate object of type java/lang/String

    allocatedString = AllocateString(jni_env);

    stringUtfChars = (*jni_env)->GetStringUTFChars(jni_env, allocatedString, NULL);

    compareRes = (stringUtfChars == NULL);

    //release stringUtfChars pointer

    (*jni_env)->ReleaseStringUTFChars(jni_env, allocatedString, stringUtfChars);

    Assert(jni_env, compareRes, "string utf chars must be NULL");

}