/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef _TD_TRANSPORT_COMM_H
#define _TD_TRANSPORT_COMM_H

#ifdef __cplusplus
extern "C" {
#endif

#include <uv.h>
#include "os.h"
#include "taoserror.h"
#include "theap.h"
#include "transLog.h"
#include "transportInt.h"
#include "trpc.h"
#include "tutil.h"

typedef void* queue[2];
/* Private macros. */
#define QUEUE_NEXT(q) (*(queue**)&((*(q))[0]))
#define QUEUE_PREV(q) (*(queue**)&((*(q))[1]))

#define QUEUE_PREV_NEXT(q) (QUEUE_NEXT(QUEUE_PREV(q)))
#define QUEUE_NEXT_PREV(q) (QUEUE_PREV(QUEUE_NEXT(q)))
/* Initialize an empty queue. */
#define QUEUE_INIT(q)    \
  {                      \
    QUEUE_NEXT(q) = (q); \
    QUEUE_PREV(q) = (q); \
  }

/* Return true if the queue has no element. */
#define QUEUE_IS_EMPTY(q) ((const queue*)(q) == (const queue*)QUEUE_NEXT(q))

/* Insert an element at the back of a queue. */
#define QUEUE_PUSH(q, e)           \
  {                                \
    QUEUE_NEXT(e) = (q);           \
    QUEUE_PREV(e) = QUEUE_PREV(q); \
    QUEUE_PREV_NEXT(e) = (e);      \
    QUEUE_PREV(q) = (e);           \
  }

/* Remove the given element from the queue. Any element can be removed at any *
 * time. */
#define QUEUE_REMOVE(e)                 \
  {                                     \
    QUEUE_PREV_NEXT(e) = QUEUE_NEXT(e); \
    QUEUE_NEXT_PREV(e) = QUEUE_PREV(e); \
  }
#define QUEUE_SPLIT(h, q, n)       \
  do {                             \
    QUEUE_PREV(n) = QUEUE_PREV(h); \
    QUEUE_PREV_NEXT(n) = (n);      \
    QUEUE_NEXT(n) = (q);           \
    QUEUE_PREV(h) = QUEUE_PREV(q); \
    QUEUE_PREV_NEXT(h) = (h);      \
    QUEUE_PREV(q) = (n);           \
  } while (0)

#define QUEUE_MOVE(h, n)        \
  do {                          \
    if (QUEUE_IS_EMPTY(h)) {    \
      QUEUE_INIT(n);            \
    } else {                    \
      queue* q = QUEUE_HEAD(h); \
      QUEUE_SPLIT(h, q, n);     \
    }                           \
  } while (0)

/* Return the element at the front of the queue. */
#define QUEUE_HEAD(q) (QUEUE_NEXT(q))

/* Return the element at the back of the queue. */
#define QUEUE_TAIL(q) (QUEUE_PREV(q))

/* Iterate over the element of a queue. * Mutating the queue while iterating
 * results in undefined behavior. */
#define QUEUE_FOREACH(q, e) for ((q) = QUEUE_NEXT(e); (q) != (e); (q) = QUEUE_NEXT(q))

/* Return the structure holding the given element. */
#define QUEUE_DATA(e, type, field) ((type*)((void*)((char*)(e)-offsetof(type, field))))

#define TRANS_RETRY_COUNT_LIMIT 100  // retry count limit
#define TRANS_RETRY_INTERVAL    15   // ms retry interval
#define TRANS_CONN_TIMEOUT      3    // connect timeout

typedef SRpcMsg      STransMsg;
typedef SRpcCtx      STransCtx;
typedef SRpcCtxVal   STransCtxVal;
typedef SRpcInfo     STrans;
typedef SRpcConnInfo STransHandleInfo;

typedef struct {
  SEpSet  epSet;     // ip list provided by app
  void*   ahandle;   // handle provided by app
  tmsg_t  msgType;   // message type
  int8_t  connType;  // connection type cli/srv
  int64_t rid;       // refId returned by taosAddRef

  int8_t     retryCount;
  STransCtx  appCtx;  //
  STransMsg* pRsp;    // for synchronous API
  tsem_t*    pSem;    // for synchronous API

  int hThrdIdx;
} STransConnCtx;

#pragma pack(push, 1)

typedef struct {
  char version : 4;  // RPC version
  char comp : 2;     // compression algorithm, 0:no compression 1:lz4
  char noResp : 2;   // noResp bits, 0: resp, 1: resp
  char persist : 2;  // persist handle,0: no persit, 1: persist handle
  char release : 2;
  char secured : 2;
  char spi : 2;

  char     user[TSDB_UNI_LEN];
  uint64_t ahandle;  // ahandle assigned by client
  uint32_t code;     // del later
  uint32_t msgType;
  int32_t  msgLen;
  uint8_t  content[0];  // message body starts from here
} STransMsgHead;

typedef struct {
  int32_t reserved;
  int32_t contLen;
} STransCompMsg;

typedef struct {
  uint32_t timeStamp;
  uint8_t  auth[TSDB_AUTH_LEN];
} STransDigestMsg;

typedef struct {
  uint8_t user[TSDB_UNI_LEN];
  uint8_t secret[TSDB_PASSWORD_LEN];
} STransUserMsg;

#pragma pack(pop)

typedef enum { Normal, Quit, Release, Register, Update } STransMsgType;
typedef enum { ConnNormal, ConnAcquire, ConnRelease, ConnBroken, ConnInPool } ConnStatus;

#define container_of(ptr, type, member) ((type*)((char*)(ptr)-offsetof(type, member)))
#define RPC_RESERVE_SIZE                (sizeof(STranConnCtx))

#define rpcIsReq(type) (type & 1U)

#define TRANS_RESERVE_SIZE (sizeof(STranConnCtx))

#define TRANS_MSG_OVERHEAD           (sizeof(STransMsgHead))
#define transHeadFromCont(cont)      ((STransMsgHead*)((char*)cont - sizeof(STransMsgHead)))
#define transContFromHead(msg)       (msg + sizeof(STransMsgHead))
#define transMsgLenFromCont(contLen) (contLen + sizeof(STransMsgHead))
#define transContLenFromMsg(msgLen)  (msgLen - sizeof(STransMsgHead));
#define transIsReq(type)             (type & 1U)

// int  rpcAuthenticateMsg(void* pMsg, int msgLen, void* pAuth, void* pKey);
// void rpcBuildAuthHead(void* pMsg, int msgLen, void* pAuth, void* pKey);
//// int32_t rpcCompressRpcMsg(char* pCont, int32_t contLen);
//
// int  transAuthenticateMsg(void* pMsg, int msgLen, void* pAuth, void* pKey);
// void transBuildAuthHead(void* pMsg, int msgLen, void* pAuth, void* pKey);
// bool transCompressMsg(char* msg, int32_t len, int32_t* flen);
// bool transDecompressMsg(char* msg, int32_t len, int32_t* flen);

void transFreeMsg(void* msg);

//
typedef struct SConnBuffer {
  char* buf;
  int   len;
  int   cap;
  int   total;
} SConnBuffer;

typedef void (*AsyncCB)(uv_async_t* handle);

typedef struct {
  void*         pThrd;
  queue         qmsg;
  TdThreadMutex mtx;  // protect qmsg;
} SAsyncItem;

typedef struct {
  int         index;
  int         nAsync;
  uv_async_t* asyncs;
} SAsyncPool;

SAsyncPool* transCreateAsyncPool(uv_loop_t* loop, int sz, void* arg, AsyncCB cb);
void        transDestroyAsyncPool(SAsyncPool* pool);
int         transSendAsync(SAsyncPool* pool, queue* mq);

int  transInitBuffer(SConnBuffer* buf);
int  transClearBuffer(SConnBuffer* buf);
int  transDestroyBuffer(SConnBuffer* buf);
int  transAllocBuffer(SConnBuffer* connBuf, uv_buf_t* uvBuf);
bool transReadComplete(SConnBuffer* connBuf);

int transSetConnOption(uv_tcp_t* stream);

void transRefSrvHandle(void* handle);
void transUnrefSrvHandle(void* handle);

void transRefCliHandle(void* handle);
void transUnrefCliHandle(void* handle);

void transReleaseCliHandle(void* handle);
void transReleaseSrvHandle(void* handle);

void transSendRequest(void* shandle, const SEpSet* pEpSet, STransMsg* pMsg, STransCtx* pCtx);
void transSendRecv(void* shandle, const SEpSet* pEpSet, STransMsg* pMsg, STransMsg* pRsp);
void transSendResponse(const STransMsg* msg);
void transRegisterMsg(const STransMsg* msg);
int  transGetConnInfo(void* thandle, STransHandleInfo* pInfo);
void transSetDefaultEpSet(void* shandle, const SEpSet* dst);

void* transInitServer(uint32_t ip, uint32_t port, char* label, int numOfThreads, void* fp, void* shandle);
void* transInitClient(uint32_t ip, uint32_t port, char* label, int numOfThreads, void* fp, void* shandle);

void transCloseClient(void* arg);
void transCloseServer(void* arg);

void  transCtxInit(STransCtx* ctx);
void  transCtxCleanup(STransCtx* ctx);
void  transCtxClear(STransCtx* ctx);
void  transCtxMerge(STransCtx* dst, STransCtx* src);
void* transCtxDumpVal(STransCtx* ctx, int32_t key);
void* transCtxDumpBrokenlinkVal(STransCtx* ctx, int32_t* msgType);

// queue sending msgs
typedef struct {
  SArray* q;
  void (*freeFunc)(const void* arg);
} STransQueue;

/*
 * init queue
 * note: queue'size is small, default 1
 */
void transQueueInit(STransQueue* queue, void (*freeFunc)(const void* arg));

/*
 * put arg into queue
 * if queue'size > 1, return false; else return true
 */
bool transQueuePush(STransQueue* queue, void* arg);
/*
 * the size of queue
 */
int32_t transQueueSize(STransQueue* queue);
/*
 * pop head from queue
 */
void* transQueuePop(STransQueue* queue);
/*
 * get ith from queue
 */
void* transQueueGet(STransQueue* queue, int i);
/*
 * rm ith from queue
 */
void* transQueueRm(STransQueue* queue, int i);
/*
 * queue empty or not
 */
bool transQueueEmpty(STransQueue* queue);
/*
 * clear queue
 */
void transQueueClear(STransQueue* queue);
/*
 * destroy queue
 */
void transQueueDestroy(STransQueue* queue);

/*
 * delay queue based on uv loop and uv timer, and only used in retry
 */
typedef struct STaskArg {
  void* param1;
  void* param2;
} STaskArg;

typedef struct SDelayTask {
  void (*func)(void* arg);
  void*    arg;
  uint64_t execTime;
  HeapNode node;
} SDelayTask;

typedef struct SDelayQueue {
  uv_timer_t* timer;
  Heap*       heap;
  uv_loop_t*  loop;
} SDelayQueue;

int transDQCreate(uv_loop_t* loop, SDelayQueue** queue);

void transDQDestroy(SDelayQueue* queue);

int transDQSched(SDelayQueue* queue, void (*func)(void* arg), void* arg, uint64_t timeoutMs);

/*
 * init global func
 */
void transThreadOnce();

#ifdef __cplusplus
}
#endif

#endif  // _TD_TRANSPORT_COMM_H