/*
 * ZeroTier One - Network Virtualization Everywhere
 * Copyright (C) 2011-2015  ZeroTier, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * --
 *
 * ZeroTier may be used and distributed under the terms of the GPLv3, which
 * are available at: http://www.gnu.org/licenses/gpl-3.0.html
 *
 * If you would like to embed ZeroTier into a commercial application or
 * redistribute it in a modified binary form, please contact ZeroTier Networks
 * LLC. Start here: http://www.zerotier.com/
 */

#include "com_zerotierone_sdk_Node.h"

#include <ZeroTierOne.h>

#include <map>
#include <assert.h>

#ifdef __cplusplus
extern "C" {
#endif

namespace {

    struct JniRef
    {
        JniRef()
            : env(NULL)
            , node(NULL)
            , dataStoreGetListener(NULL)
            , dataStorePutListener(NULL)
            , packetSender(NULL)
            , frameListener(NULL)
            , configListener(NULL)
        {}
        uint64_t id;

        JNIEnv *env;

        ZT1_Node *node;

        jobject dataStoreGetListener;
        jobject dataStorePutListener;
        jobject packetSender;
        jobject frameListener;
        jobject configListener;
    };


    int VirtualNetworkConfigFunctionCallback(ZT1_Node *node,void *userData,uint64_t,enum ZT1_VirtualNetworkConfigOperation,const ZT1_VirtualNetworkConfig *)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;

        return 0;
    }

    void VirtualNetworkFrameFunctionCallback(ZT1_Node *node,void *userData,uint64_t,uint64_t,uint64_t,unsigned int,unsigned int,const void *,unsigned int)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;
    }

    void EventCallback(ZT1_Node *node,void *userData,enum ZT1_Event,const void *)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;
    }

    long DataStoreGetFunction(ZT1_Node *node,void *userData,const char *,void *,unsigned long,unsigned long,unsigned long *)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;

        return 0;
    }

    int DataStorePutFunction(ZT1_Node *node,void *userData,const char *,const void *,unsigned long,int)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;

        return 0;
    }

    int WirePacketSendFunction(ZT1_Node *node,void *userData,const struct sockaddr_storage *,unsigned int,const void *,unsigned int)
    {
        JniRef *ref = (JniRef*)userData;
        assert(ref->node == node);

        JNIEnv *env = ref->env;

        return 0;
    }

    typedef std::map<uint64_t, JniRef*> NodeMap;
    static NodeMap nodeMap;

    jobject createResultObject(JNIEnv *env, ZT1_ResultCode code)
    {
        // cache the class and constructor so we don't have to
        // look them up every time we need to create a java
        // ResultCode object
        static jclass resultClass = NULL;
        static jmethodID constructorId = NULL;

        jobject resultObject = NULL;

        if(resultClass == NULL)
        {
            resultClass = env->FindClass("com/zerotierone/sdk/ResultCode");
            if(resultClass == NULL)
            {
                return NULL; // exception thrown
            }
        }

        if(constructorId = NULL)
        {
            constructorId = env->GetMethodID(resultClass, "<init>", "(I)V");
            if(constructorId == NULL)
            {
                return NULL; // exception thrown
            }
        }

        resultObject = env->NewObject(resultClass, constructorId, (jlong)code);

        return resultObject;
    }
}

/*
 * Class:     com_zerotierone_sdk_Node
 * Method:    node_init
 * Signature: (J)Lcom/zerotierone/sdk/ResultCode;
 */
JNIEXPORT jobject JNICALL Java_com_zerotierone_sdk_Node_node_1init
  (JNIEnv *env, jobject obj, jlong now)
{
    jobject resultObject = createResultObject(env, ZT1_RESULT_OK);

    ZT1_Node *node;
    JniRef *ref = new JniRef;

    ZT1_ResultCode rc = ZT1_Node_new(
        &node,
        ref,
        (uint64_t)now,
        &DataStoreGetFunction,
        &DataStorePutFunction,
        &WirePacketSendFunction,
        &VirtualNetworkFrameFunctionCallback,
        &VirtualNetworkConfigFunctionCallback,
        &EventCallback);

    if(rc != ZT1_RESULT_OK)
    {
        resultObject = createResultObject(env, rc);
        if(node)
        {
            ZT1_Node_delete(node);
            node = NULL;
        }
        delete ref;
        ref = NULL;
        return resultObject;
    }

    
    ref->id = (uint64_t)now;
    ref->env = env;
    ref->node = node;

    jclass cls = env->GetObjectClass(obj);
    jfieldID fid = env->GetFieldID(
        cls, "getListener", "Lcom.zerotierone.sdk.DataStoreGetListener;");

    if(fid == NULL)
    {
        return NULL; // exception already thrown
    }

    ref->dataStoreGetListener = env->GetObjectField(obj, fid);
    if(ref->dataStoreGetListener == NULL)
    {
        return NULL;
    }

    fid = env->GetFieldID(
        cls, "putListener", "Lcom.zerotierone.sdk.DataStorePutLisetner;");

    if(fid == NULL)
    {
        return NULL; // exception already thrown
    }

    ref->dataStorePutListener = env->GetObjectField(obj, fid);
    if(ref->dataStorePutListener == NULL)
    {
        return NULL;
    }

    fid = env->GetFieldID(
        cls, "sender", "Lcom.zerotierone.sdk.PacketSender;");
    if(fid == NULL)
    {
        return NULL; // exception already thrown
    }

    ref->packetSender = env->GetObjectField(obj, fid);
    if(ref->packetSender == NULL)
    {
        return NULL;
    }

    fid = env->GetFieldID(
        cls, "frameListener", "Lcom.zerotierone.sdk.VirtualNetworkFrameListener;");
    if(fid == NULL)
    {
        return NULL; // exception already thrown
    }

    ref->frameListener = env->GetObjectField(obj, fid);
    if(ref->frameListener = NULL)
    {
        return NULL;
    }

    fid = env->GetFieldID(
        cls, "configListener", "Lcom.zerotierone.sdk.VirtualNetworkConfigListener;");
    if(fid == NULL)
    {
        return NULL; // exception already thrown
    }

    ref->configListener = env->GetObjectField(obj, fid);
    if(ref->configListener == NULL)
    {
        return NULL;
    }

    nodeMap.insert(std::make_pair(ref->id, ref));

    return resultObject;
}

/*
 * Class:     com_zerotierone_sdk_Node
 * Method:    node_delete
 * Signature: (J)V
 */
JNIEXPORT void JNICALL Java_com_zerotierone_sdk_Node_node_1delete
  (JNIEnv *env, jobject obj, jlong id)
{
    uint64_t nodeId = (uint64_t)id;

    NodeMap::iterator found = nodeMap.find(nodeId);
    if(found != nodeMap.end())
    {
        JniRef *ref = found->second;
        nodeMap.erase(found);
        delete ref;
        ref = NULL;
    }
}

/*
 * Class:     com_zerotierone_sdk_Node
 * Method:    processVirtualNetworkFrame
 * Signature: (JJJJJII[B[J)Lcom/zerotierone/sdk/ResultCode;
 */
JNIEXPORT jobject JNICALL Java_com_zerotierone_sdk_Node_processVirtualNetworkFrame
   (JNIEnv *env, jobject obj, 
    jlong id, 
    jlong in_now, 
    jlong in_nwid,
    jlong in_sourceMac,
    jlong in_destMac,
    jint in_etherType,
    jint in_vlanId,
    jbyteArray in_frameData,
    jlongArray out_nextBackgroundTaskDeadline)
{
    uint64_t nodeId = (uint64_t) id;
    NodeMap::iterator found = nodeMap.find(nodeId);
    if(found == nodeMap.end())
    {
        // cannot find valid node.  We should  never get here.
        return createResultObject(env, ZT1_RESULT_FATAL_ERROR_INTERNAL);
    }

    unsigned int nbtd_len = env->GetArrayLength(out_nextBackgroundTaskDeadline);
    if(nbtd_len < 1)
    {
        // array for next background task length has 0 elements!
        return createResultObject(env, ZT1_RESULT_FATAL_ERROR_INTERNAL);
    }

    ZT1_Node *node = found->second;

    uint64_t now = (uint64_t)in_now;
    uint64_t nwid = (uint64_t)in_nwid;
    uint64_t sourceMac = (uint64_t)in_sourceMac;
    uint64_t destMac = (uint64_t)in_destMac;
    unsigned int etherType = (unsigned int)in_etherType;
    unsigned int vlanId = (unsigned int)in_vlanId;

    unsigned int frameLength = env->GetArrayLength(in_frameData);
    jbyte *frameData =env->GetByteArrayElements(in_frameData, NULL);

    uint64_t nextBackgroundTaskDeadline = 0;

    ZT1_ResultCode rc = ZT1_Node_processVirtualNetworkFrame(
        node,
        now,
        nwid,
        sourceMac,
        destMac,
        etherType,
        vlanId,
        (const void*)frameData,
        frameLength,
        &nextBackgroundTaskDeadline);

    jlong *outDeadline = env->GetLongArrayElements(out_nextBackgroundTaskDeadline, NULL);
    outDeadline[0] = (jlong)nextBackgroundTaskDeadline;
    env->ReleaseLongArrayElements(out_nextBackgroundTaskDeadline, outDeadline, 0);

    env->ReleaseByteArrayElements(in_frameData, frameData, 0);

    return createResultObject(env, rc);
}


#ifdef __cplusplus
} // extern "C"
#endif