/*
 * Copyright (c) 2003, 2018, 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 <stdio.h>
#include <string.h>
#include <jvmti.h>
#include "agent_common.h"
#include "JVMTITools.h"

#ifdef __cplusplus
extern "C" {
#endif

#ifndef JNI_ENV_ARG

#ifdef __cplusplus
#define JNI_ENV_ARG(x, y) y
#define JNI_ENV_PTR(x) x
#else
#define JNI_ENV_ARG(x,y) x, y
#define JNI_ENV_PTR(x) (*x)
#endif

#endif

#define STATUS_FAILED 2
#define PASSED 0

static jvmtiEnv *jvmti = NULL;
static jvmtiCapabilities caps;

#ifdef STATIC_BUILD
JNIEXPORT jint JNICALL Agent_OnLoad_redefclass006(JavaVM *jvm, char *options, void *reserved) {
    return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNICALL Agent_OnAttach_redefclass006(JavaVM *jvm, char *options, void *reserved) {
    return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNI_OnLoad_redefclass006(JavaVM *jvm, char *options, void *reserved) {
    return JNI_VERSION_1_8;
}
#endif
jint  Agent_Initialize(JavaVM *vm, char *options, void *reserved) {
    jint res;
    jvmtiError err;

    if ((res = JNI_ENV_PTR(vm)->GetEnv(JNI_ENV_ARG(vm, (void **) &jvmti),
            JVMTI_VERSION_1_1)) != JNI_OK) {
        printf("%s: Failed to call GetEnv: error=%d\n", __FILE__, res);
        return JNI_ERR;
    }

    err = jvmti->GetPotentialCapabilities(&caps);
    if (err != JVMTI_ERROR_NONE) {
        printf("(GetPotentialCapabilities) unexpected error: %s (%d)\n",
               TranslateError(err), err);
        return JNI_ERR;
    }

    err = jvmti->AddCapabilities(&caps);
    if (err != JVMTI_ERROR_NONE) {
        printf("(AddCapabilities) unexpected error: %s (%d)\n",
               TranslateError(err), err);
        return JNI_ERR;
    }

    err = jvmti->GetCapabilities(&caps);
    if (err != JVMTI_ERROR_NONE) {
        printf("(GetCapabilities) unexpected error: %s (%d)\n",
               TranslateError(err), err);
        return JNI_ERR;
    }

    if (!caps.can_redefine_classes) {
        printf("Warning: RedefineClasses is not implemented\n");
    }

    return JNI_OK;
}

JNIEXPORT jint JNICALL
Java_nsk_jvmti_RedefineClasses_redefclass006_makeRedefinition(JNIEnv *env,
        jclass cls, jint t_case, jclass redefCls, jbyteArray classBytes) {
    jvmtiError err;
    jvmtiClassDefinition classDef;
    jvmtiClassDefinition* classDefPtr = NULL;

    if (jvmti == NULL) {
        printf("JVMTI client was not properly loaded!\n");
        return STATUS_FAILED;
    }

    if (!caps.can_redefine_classes) {
        return PASSED;
    }

    switch(t_case) {
/* NULL pointer to the jvmtiClassDefinition */
        case 0:
            break;
/* NULL pointer to the jvmtiClassDefinition in debug mode */
        case 1:
            printf("Invoke RedefineClasses() with NULL pointer to the structure jvmtiClassDefinition\n");
            fflush(stdout);
            break;
/* NULL pointer to the jvmtiClassDefinition->class_bytes in debug mode */
        case 3:
            printf("Invoke RedefineClasses() with NULL pointer to the field jvmtiClassDefinition->class_bytes\n");
            fflush(stdout);
            // fallthrough
/* NULL pointer to the jvmtiClassDefinition->class_bytes */
        case 2:
            /* partly fill the structure jvmtiClassDefinition */
            classDef.klass = redefCls;
            classDef.class_byte_count =
                JNI_ENV_PTR(env)->GetArrayLength(JNI_ENV_ARG(env, classBytes));
            classDef.class_bytes = NULL;
            classDefPtr = &classDef;
            break;
    }

/* explode the bomb */
    if ((err = (jvmti->RedefineClasses(1, classDefPtr))) != JVMTI_ERROR_NULL_POINTER) {
        printf("TEST FAILED: the function RedefineClasses() returned error %d: %s\n",
            err, TranslateError(err));
        printf("\tBut it should return the error JVMTI_ERROR_NULL_POINTER.\n");
        return STATUS_FAILED;
    }

    return PASSED;
}

#ifdef __cplusplus
}
#endif