/*
 * Copyright (c) 2007, 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 <stdlib.h>
#include <string.h>
#include <jvmti.h>
#include "agent_common.h"
#include <jni.h>
#include "jvmti_tools.h"
#include "jni_tools.h"
#include "JVMTITools.h"

#ifdef __cplusplus
extern "C" {
#endif

#define FILE_NAME "nsk/jvmti/scenarios/hotswap/HS204/hs204t003/MyThread"
#define CLASS_NAME  "Lnsk/jvmti/scenarios/hotswap/HS204/hs204t003/MyThread;"
#define FIELDNAME "intState"
#define TYPE "I"

static jint redefineNumber;
static jvmtiEnv * jvmti;
static jclass watchFieldClass;

JNIEXPORT void JNICALL callbackClassPrepare(jvmtiEnv *jvmti_env,
        JNIEnv* jni,
        jthread thread,
        jclass klass) {
    char * className;
    char * generic;

    className = NULL;
    generic   = NULL;
    redefineNumber=0;
    if ( !NSK_JVMTI_VERIFY(NSK_CPP_STUB4(GetClassSignature, jvmti_env,
                    klass, &className, &generic)) ) {
        NSK_DISPLAY0(" Agent :: Failed get class signature.\n");
        nsk_jvmti_agentFailed();
    } else {
        if( (strcmp(className, CLASS_NAME) == 0 ) ) {
            jfieldID fieldId;
            if ( ! NSK_JNI_VERIFY(jni, (fieldId = NSK_CPP_STUB4(GetStaticFieldID,
                                jni, klass, FIELDNAME, TYPE) ) != NULL ) ) {
                    NSK_DISPLAY0(" Agent :: Failed to get FieldId.\n");
                    nsk_jvmti_agentFailed();
            } else {
                if ( ! NSK_JVMTI_VERIFY( NSK_CPP_STUB3(SetFieldAccessWatch,
                                jvmti_env, klass, fieldId) )  ) {
                    NSK_DISPLAY0(" Agent :: Failed to set watch point on a field.\n");
                    nsk_jvmti_agentFailed();
                } else {
                    nsk_jvmti_enableNotification(jvmti_env, JVMTI_EVENT_FIELD_ACCESS, NULL);
                    if (! NSK_JNI_VERIFY(jni,
                                ( watchFieldClass = (jclass)
                                  NSK_CPP_STUB2(NewGlobalRef, jni, klass) )
                                != NULL ) ) {
                        NSK_DISPLAY0(" Agent :: Failed to get global reference for class.\n");
                        nsk_jvmti_agentFailed();
                    }
                    NSK_DISPLAY0(" Agent :: SetFieldAccessWatch.\n");
                }
            }
            NSK_DISPLAY1(" Agent :: Leaving callbackClassPrepare for class = %s .\n", className);
        }
    }

    if ( className != NULL ) {
        if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, jvmti_env, (unsigned char *)className))) {
            NSK_DISPLAY1(" Agent :: #error failed to Deallocate className = %s.", className);
            nsk_jvmti_agentFailed();
        }
    }

    if ( generic != NULL ) {
        if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, jvmti_env, (unsigned char *)generic))) {
            NSK_DISPLAY1(" Agent :: #error failed to Deallocate class signature = %s.", generic);
            nsk_jvmti_agentFailed();
        }
    }
    return;
}

JNIEXPORT void JNICALL callbackFieldAccess(jvmtiEnv *jvmti_env,
        JNIEnv* jni,
        jthread thread,
        jmethodID method,
        jlocation location,
        jclass field_klass,
        jobject object,
        jfieldID field) {
    char fileName[512];
    char * className;
    char * generic;

    className = NULL;
    generic   = NULL;
    if (redefineNumber != 0 ) {
        return;
    }
    if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB4(GetClassSignature, jvmti_env,
                    field_klass, &className, &generic)) ) {
        NSK_DISPLAY0(" Agent :: Failed get class signature.\n");
        nsk_jvmti_agentFailed();
    } else {
        if( (strcmp(className, CLASS_NAME) == 0 ) ) {
            jvmtiThreadInfo info;
            nsk_jvmti_getFileName(redefineNumber, FILE_NAME, fileName,
                    sizeof(fileName)/sizeof(char));
            if ( nsk_jvmti_redefineClass(jvmti_env, field_klass, fileName) == NSK_TRUE ) {
                NSK_DISPLAY0(" Agent :: Successfully redefined.\n");
                redefineNumber++;
            } else {
                NSK_DISPLAY0(" Agent :: Failed to redefine.\n");
                nsk_jvmti_agentFailed();
            }
            NSK_DISPLAY0(" Agent :: Before attempting thread suspend.\n");
            if ( ! NSK_JVMTI_VERIFY( NSK_CPP_STUB3(GetThreadInfo, jvmti_env, thread , &info)) ) {
                NSK_DISPLAY0(" Agent :: error getting thread info ");
                nsk_jvmti_agentFailed();
            } else {
                NSK_DISPLAY1(" Agent :: Thread Name = %s .\n", info.name);
            }
            if ( ! NSK_JVMTI_VERIFY( NSK_CPP_STUB2(SuspendThread, jvmti_env, thread)) ) {
                NSK_DISPLAY0(" Agent :: Failed to suspend thread.\n");
                nsk_jvmti_agentFailed();
            }
        }
    }

    if ( className != NULL ) {
        if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, jvmti_env, (unsigned char *)className))) {
            NSK_DISPLAY1(" Agent :: #error failed to Deallocate className = %s.", className);
            nsk_jvmti_agentFailed();
        }
    }

    if ( generic != NULL ) {
        if (!NSK_JVMTI_VERIFY(NSK_CPP_STUB2(Deallocate, jvmti_env, (unsigned char *)generic))) {
            NSK_DISPLAY1(" Agent :: #error failed to Deallocate class signature = %s.", generic);
            nsk_jvmti_agentFailed();
        }
    }
}

#ifdef STATIC_BUILD
JNIEXPORT jint JNICALL Agent_OnLoad_hs204t003(JavaVM *jvm, char *options, void *reserved) {
    return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNICALL Agent_OnAttach_hs204t003(JavaVM *jvm, char *options, void *reserved) {
    return Agent_Initialize(jvm, options, reserved);
}
JNIEXPORT jint JNI_OnLoad_hs204t003(JavaVM *jvm, char *options, void *reserved) {
    return JNI_VERSION_1_8;
}
#endif
jint  Agent_Initialize(JavaVM *vm, char *options, void *reserved) {
    if ( ! NSK_JVMTI_VERIFY ( NSK_CPP_STUB3(GetEnv, vm,
                    (void **)&jvmti, JVMTI_VERSION_1_1) ) ) {
        NSK_DISPLAY0("Agent :: Could not load JVMTI interface \n");
        return JNI_ERR;
    } else {
        jvmtiCapabilities caps;
        jvmtiEventCallbacks eventCallbacks;
        memset(&caps, 0, sizeof(caps));
        if (!nsk_jvmti_parseOptions(options)) {
            NSK_DISPLAY0(" NSK Failed to parse..");
            return JNI_ERR;
        }
        caps.can_redefine_classes             = 1;
        caps.can_generate_field_access_events = 1;
        caps.can_pop_frame                    = 1;
        caps.can_suspend                      = 1;
        if ( ! NSK_JVMTI_VERIFY(NSK_CPP_STUB2( AddCapabilities, jvmti, &caps)) ) {
            NSK_DISPLAY0(" Agent :: Failed add required capabilities\n.");
            return JNI_ERR;
        }
        memset(&eventCallbacks, 0, sizeof(eventCallbacks));
        eventCallbacks.ClassPrepare = callbackClassPrepare;
        eventCallbacks.FieldAccess  = callbackFieldAccess;
        if (!NSK_JVMTI_VERIFY( NSK_CPP_STUB3(SetEventCallbacks, jvmti,
                        &eventCallbacks, sizeof(eventCallbacks) ) ) ) {
            NSK_DISPLAY0(" Agent :: Error occured while setting event call back \n");
            return JNI_ERR;
        }
        nsk_jvmti_enableNotification(jvmti, JVMTI_EVENT_CLASS_PREPARE, NULL);
    }
    return JNI_OK;
}

JNIEXPORT jboolean JNICALL
Java_nsk_jvmti_scenarios_hotswap_HS204_hs204t003_hs204t003_popFrame(JNIEnv * jni,
        jobject object,
        jthread thread) {
    jboolean retvalue;
    jint state;
    retvalue = JNI_FALSE;
    if (! NSK_JVMTI_VERIFY( NSK_CPP_STUB3(GetThreadState, jvmti, thread, &state)) ){
        NSK_DISPLAY0(" Agent :: Error getting thread state.\n");
        nsk_jvmti_agentFailed();
    } else {
        if ( state & JVMTI_THREAD_STATE_SUSPENDED) {
            NSK_DISPLAY0(" Agent :: Thread state = JVMTI_THREAD_STATE_SUSPENDED.\n");
            if ( ! NSK_JVMTI_VERIFY ( NSK_CPP_STUB2(PopFrame, jvmti, thread) ) ) {
                NSK_DISPLAY0("#error Agent :: Jvmti failed to do popFrame.\n");
                nsk_jvmti_agentFailed();
            } else {
                if ( ! NSK_JVMTI_VERIFY ( NSK_CPP_STUB2(ResumeThread, jvmti, thread)) ) {
                    NSK_DISPLAY0(" Agent :: Error occured in resuming a thread.\n");
                    nsk_jvmti_agentFailed();
                } else {
                    jfieldID fieldId;
                    if ( ! NSK_JNI_VERIFY(jni, (fieldId = NSK_CPP_STUB4(GetStaticFieldID,
                                jni, watchFieldClass, FIELDNAME, TYPE) ) != NULL ) ) {
                        NSK_DISPLAY0(" Agent :: Failed to get FieldId before droping watchers.\n");
                        nsk_jvmti_agentFailed();
                    } else {
                        if ( ! NSK_JVMTI_VERIFY ( NSK_CPP_STUB3(ClearFieldAccessWatch,
                                        jvmti, watchFieldClass, fieldId)) ) {
                            NSK_DISPLAY0(" Agent :: failed to drop field watces.\n");
                            nsk_jvmti_agentFailed();
                        } else {
                            NSK_DISPLAY0(" Agent :: Sucessfully droped watches.\n");
                            retvalue = JNI_TRUE;
                        }
                    }
                }
            }
        } else {
            NSK_DISPLAY0(" Agent :: Thread should be suspended to its pop frame.\n");
        }
    }
    return retvalue;
}
#ifdef __cplusplus
}
#endif