/*
 * 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/>.
 */

#define _DEFAULT_SOURCE
#include "mndFunc.h"
#include "mndPrivilege.h"
#include "mndShow.h"
#include "mndSync.h"
#include "mndTrans.h"
#include "mndUser.h"

#define SDB_FUNC_VER          2
#define SDB_FUNC_RESERVE_SIZE 64

static SSdbRaw *mndFuncActionEncode(SFuncObj *pFunc);
static SSdbRow *mndFuncActionDecode(SSdbRaw *pRaw);
static int32_t  mndFuncActionInsert(SSdb *pSdb, SFuncObj *pFunc);
static int32_t  mndFuncActionDelete(SSdb *pSdb, SFuncObj *pFunc);
static int32_t  mndFuncActionUpdate(SSdb *pSdb, SFuncObj *pOld, SFuncObj *pNew);
static int32_t  mndCreateFunc(SMnode *pMnode, SRpcMsg *pReq, SCreateFuncReq *pCreate);
static int32_t  mndDropFunc(SMnode *pMnode, SRpcMsg *pReq, SFuncObj *pFunc);
static int32_t  mndProcessCreateFuncReq(SRpcMsg *pReq);
static int32_t  mndProcessDropFuncReq(SRpcMsg *pReq);
static int32_t  mndProcessRetrieveFuncReq(SRpcMsg *pReq);
static int32_t  mndRetrieveFuncs(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pBlock, int32_t rows);
static void     mndCancelGetNextFunc(SMnode *pMnode, void *pIter);

int32_t mndInitFunc(SMnode *pMnode) {
  SSdbTable table = {
      .sdbType = SDB_FUNC,
      .keyType = SDB_KEY_BINARY,
      .encodeFp = (SdbEncodeFp)mndFuncActionEncode,
      .decodeFp = (SdbDecodeFp)mndFuncActionDecode,
      .insertFp = (SdbInsertFp)mndFuncActionInsert,
      .updateFp = (SdbUpdateFp)mndFuncActionUpdate,
      .deleteFp = (SdbDeleteFp)mndFuncActionDelete,
  };

  mndSetMsgHandle(pMnode, TDMT_MND_CREATE_FUNC, mndProcessCreateFuncReq);
  mndSetMsgHandle(pMnode, TDMT_MND_DROP_FUNC, mndProcessDropFuncReq);
  mndSetMsgHandle(pMnode, TDMT_MND_RETRIEVE_FUNC, mndProcessRetrieveFuncReq);

  mndAddShowRetrieveHandle(pMnode, TSDB_MGMT_TABLE_FUNC, mndRetrieveFuncs);
  mndAddShowFreeIterHandle(pMnode, TSDB_MGMT_TABLE_FUNC, mndCancelGetNextFunc);

  return sdbSetTable(pMnode->pSdb, table);
}

void mndCleanupFunc(SMnode *pMnode) {}

static SSdbRaw *mndFuncActionEncode(SFuncObj *pFunc) {
  terrno = TSDB_CODE_OUT_OF_MEMORY;

  int32_t  size = pFunc->commentSize + pFunc->codeSize + sizeof(SFuncObj) + SDB_FUNC_RESERVE_SIZE;
  SSdbRaw *pRaw = sdbAllocRaw(SDB_FUNC, SDB_FUNC_VER, size);
  if (pRaw == NULL) goto _OVER;

  int32_t dataPos = 0;
  SDB_SET_BINARY(pRaw, dataPos, pFunc->name, TSDB_FUNC_NAME_LEN, _OVER)
  SDB_SET_INT64(pRaw, dataPos, pFunc->createdTime, _OVER)
  SDB_SET_INT8(pRaw, dataPos, pFunc->funcType, _OVER)
  SDB_SET_INT8(pRaw, dataPos, pFunc->scriptType, _OVER)
  SDB_SET_INT8(pRaw, dataPos, pFunc->align, _OVER)
  SDB_SET_INT8(pRaw, dataPos, pFunc->outputType, _OVER)
  SDB_SET_INT32(pRaw, dataPos, pFunc->outputLen, _OVER)
  SDB_SET_INT32(pRaw, dataPos, pFunc->bufSize, _OVER)
  SDB_SET_INT64(pRaw, dataPos, pFunc->signature, _OVER)
  SDB_SET_INT32(pRaw, dataPos, pFunc->commentSize, _OVER)
  SDB_SET_INT32(pRaw, dataPos, pFunc->codeSize, _OVER)
  if (pFunc->commentSize > 0) {
    SDB_SET_BINARY(pRaw, dataPos, pFunc->pComment, pFunc->commentSize, _OVER)
  }
  SDB_SET_BINARY(pRaw, dataPos, pFunc->pCode, pFunc->codeSize, _OVER)
  SDB_SET_INT32(pRaw, dataPos, pFunc->funcVersion, _OVER)
  SDB_SET_RESERVE(pRaw, dataPos, SDB_FUNC_RESERVE_SIZE, _OVER)
  SDB_SET_DATALEN(pRaw, dataPos, _OVER);

  terrno = 0;

_OVER:
  if (terrno != 0) {
    mError("func:%s, failed to encode to raw:%p since %s", pFunc->name, pRaw, terrstr());
    sdbFreeRaw(pRaw);
    return NULL;
  }

  mTrace("func:%s, encode to raw:%p, row:%p", pFunc->name, pRaw, pFunc);
  return pRaw;
}

static SSdbRow *mndFuncActionDecode(SSdbRaw *pRaw) {
  terrno = TSDB_CODE_OUT_OF_MEMORY;
  SSdbRow  *pRow = NULL;
  SFuncObj *pFunc = NULL;

  int8_t sver = 0;
  if (sdbGetRawSoftVer(pRaw, &sver) != 0) goto _OVER;

  if (sver != 1 && sver != 2) {
    terrno = TSDB_CODE_SDB_INVALID_DATA_VER;
    goto _OVER;
  }

  pRow = sdbAllocRow(sizeof(SFuncObj));
  if (pRow == NULL) goto _OVER;

  pFunc = sdbGetRowObj(pRow);
  if (pFunc == NULL) goto _OVER;

  int32_t dataPos = 0;
  SDB_GET_BINARY(pRaw, dataPos, pFunc->name, TSDB_FUNC_NAME_LEN, _OVER)
  SDB_GET_INT64(pRaw, dataPos, &pFunc->createdTime, _OVER)
  SDB_GET_INT8(pRaw, dataPos, &pFunc->funcType, _OVER)
  SDB_GET_INT8(pRaw, dataPos, &pFunc->scriptType, _OVER)
  SDB_GET_INT8(pRaw, dataPos, &pFunc->align, _OVER)
  SDB_GET_INT8(pRaw, dataPos, &pFunc->outputType, _OVER)
  SDB_GET_INT32(pRaw, dataPos, &pFunc->outputLen, _OVER)
  SDB_GET_INT32(pRaw, dataPos, &pFunc->bufSize, _OVER)
  SDB_GET_INT64(pRaw, dataPos, &pFunc->signature, _OVER)
  SDB_GET_INT32(pRaw, dataPos, &pFunc->commentSize, _OVER)
  SDB_GET_INT32(pRaw, dataPos, &pFunc->codeSize, _OVER)

  if (pFunc->commentSize > 0) {
    pFunc->pComment = taosMemoryCalloc(1, pFunc->commentSize);
    if (pFunc->pComment == NULL) {
      goto _OVER;
    }
    SDB_GET_BINARY(pRaw, dataPos, pFunc->pComment, pFunc->commentSize, _OVER)
  }

  pFunc->pCode = taosMemoryCalloc(1, pFunc->codeSize);
  if (pFunc->pCode == NULL) {
    goto _OVER;
  }
  SDB_GET_BINARY(pRaw, dataPos, pFunc->pCode, pFunc->codeSize, _OVER)

  if (sver >= 2) {
    SDB_GET_INT32(pRaw, dataPos, &pFunc->funcVersion, _OVER)
  }

  SDB_GET_RESERVE(pRaw, dataPos, SDB_FUNC_RESERVE_SIZE, _OVER)

  taosInitRWLatch(&pFunc->lock);

  terrno = 0;

_OVER:
  if (terrno != 0) {
    mError("func:%s, failed to decode from raw:%p since %s", pFunc == NULL ? "null" : pFunc->name, pRaw, terrstr());
    taosMemoryFreeClear(pRow);
    return NULL;
  }

  mTrace("func:%s, decode from raw:%p, row:%p", pFunc->name, pRaw, pFunc);
  return pRow;
}

static int32_t mndFuncActionInsert(SSdb *pSdb, SFuncObj *pFunc) {
  mTrace("func:%s, perform insert action, row:%p", pFunc->name, pFunc);
  return 0;
}

static int32_t mndFuncActionDelete(SSdb *pSdb, SFuncObj *pFunc) {
  mTrace("func:%s, perform delete action, row:%p", pFunc->name, pFunc);
  taosMemoryFreeClear(pFunc->pCode);
  taosMemoryFreeClear(pFunc->pComment);
  return 0;
}

static int32_t mndFuncActionUpdate(SSdb *pSdb, SFuncObj *pOld, SFuncObj *pNew) {
  mTrace("func:%s, perform update action, old row:%p new row:%p", pOld->name, pOld, pNew);

  taosWLockLatch(&pOld->lock);

  pOld->align = pNew->align;
  pOld->bufSize = pNew->bufSize;
  pOld->codeSize = pNew->codeSize;
  pOld->commentSize = pNew->commentSize;
  pOld->createdTime = pNew->createdTime;
  pOld->funcType = pNew->funcType;
  pOld->funcVersion = pNew->funcVersion;
  pOld->outputLen = pNew->outputLen;
  pOld->outputType = pNew->outputType;

  if (pOld->pComment != NULL) {
    taosMemoryFree(pOld->pComment);
    pOld->pComment = NULL;
  }
  if (pNew->commentSize > 0 && pNew->pComment != NULL) {
    pOld->commentSize = pNew->commentSize;
    pOld->pComment = taosMemoryMalloc(pOld->commentSize);
    memcpy(pOld->pComment, pNew->pComment, pOld->commentSize);
  }

  if (pOld->pCode != NULL) {
    taosMemoryFree(pOld->pCode);
    pOld->pCode = NULL;
  }
  if (pNew->codeSize > 0 && pNew->pCode != NULL) {
    pOld->codeSize = pNew->codeSize;
    pOld->pCode = taosMemoryMalloc(pOld->codeSize);
    memcpy(pOld->pCode, pNew->pCode, pOld->codeSize);
  }

  pOld->scriptType = pNew->scriptType;
  pOld->signature = pNew->signature;

  taosWUnLockLatch(&pOld->lock);

  return 0;
}

static SFuncObj *mndAcquireFunc(SMnode *pMnode, char *funcName) {
  SSdb     *pSdb = pMnode->pSdb;
  SFuncObj *pFunc = sdbAcquire(pSdb, SDB_FUNC, funcName);
  if (pFunc == NULL && terrno == TSDB_CODE_SDB_OBJ_NOT_THERE) {
    terrno = TSDB_CODE_MND_FUNC_NOT_EXIST;
  }
  return pFunc;
}

static void mndReleaseFunc(SMnode *pMnode, SFuncObj *pFunc) {
  SSdb *pSdb = pMnode->pSdb;
  sdbRelease(pSdb, pFunc);
}

static int32_t mndCreateFunc(SMnode *pMnode, SRpcMsg *pReq, SCreateFuncReq *pCreate) {
  int32_t code = -1;
  STrans *pTrans = NULL;

  if ((terrno = grantCheck(TSDB_GRANT_USER)) < 0) {
    return code;
  }

  SFuncObj func = {0};
  memcpy(func.name, pCreate->name, TSDB_FUNC_NAME_LEN);
  func.createdTime = taosGetTimestampMs();
  func.funcType = pCreate->funcType;
  func.scriptType = pCreate->scriptType;
  func.outputType = pCreate->outputType;
  func.outputLen = pCreate->outputLen;
  func.bufSize = pCreate->bufSize;
  func.signature = pCreate->signature;
  if (NULL != pCreate->pComment) {
    func.commentSize = strlen(pCreate->pComment) + 1;
    func.pComment = taosMemoryMalloc(func.commentSize);
  }
  func.codeSize = pCreate->codeLen;
  func.pCode = taosMemoryMalloc(func.codeSize);
  if (func.pCode == NULL || func.pCode == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    goto _OVER;
  }

  if (func.commentSize > 0) {
    memcpy(func.pComment, pCreate->pComment, func.commentSize);
  }
  memcpy(func.pCode, pCreate->pCode, func.codeSize);

  pTrans = mndTransCreate(pMnode, TRN_POLICY_ROLLBACK, TRN_CONFLICT_NOTHING, pReq, "create-func");
  if (pTrans == NULL) goto _OVER;
  mInfo("trans:%d, used to create func:%s", pTrans->id, pCreate->name);

  SFuncObj *oldFunc = mndAcquireFunc(pMnode, pCreate->name);
  if (pCreate->orReplace == 1 && oldFunc != NULL) {
    func.funcVersion = oldFunc->funcVersion + 1;
    func.createdTime = oldFunc->createdTime;

    SSdbRaw *pRedoRaw = mndFuncActionEncode(oldFunc);
    if (pRedoRaw == NULL || mndTransAppendRedolog(pTrans, pRedoRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pRedoRaw, SDB_STATUS_READY) != 0) goto _OVER;

    SSdbRaw *pUndoRaw = mndFuncActionEncode(oldFunc);
    if (pUndoRaw == NULL || mndTransAppendUndolog(pTrans, pUndoRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pUndoRaw, SDB_STATUS_READY) != 0) goto _OVER;

    SSdbRaw *pCommitRaw = mndFuncActionEncode(&func);
    if (pCommitRaw == NULL || mndTransAppendCommitlog(pTrans, pCommitRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pCommitRaw, SDB_STATUS_READY) != 0) goto _OVER;
  } else {
    SSdbRaw *pRedoRaw = mndFuncActionEncode(&func);
    if (pRedoRaw == NULL || mndTransAppendRedolog(pTrans, pRedoRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pRedoRaw, SDB_STATUS_CREATING) != 0) goto _OVER;

    SSdbRaw *pUndoRaw = mndFuncActionEncode(&func);
    if (pUndoRaw == NULL || mndTransAppendUndolog(pTrans, pUndoRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pUndoRaw, SDB_STATUS_DROPPED) != 0) goto _OVER;

    SSdbRaw *pCommitRaw = mndFuncActionEncode(&func);
    if (pCommitRaw == NULL || mndTransAppendCommitlog(pTrans, pCommitRaw) != 0) goto _OVER;
    if (sdbSetRawStatus(pCommitRaw, SDB_STATUS_READY) != 0) goto _OVER;
  }

  if (mndTransPrepare(pMnode, pTrans) != 0) goto _OVER;

  code = 0;

_OVER:
  if (oldFunc != NULL) {
    mndReleaseFunc(pMnode, oldFunc);
  }

  taosMemoryFree(func.pCode);
  taosMemoryFree(func.pComment);
  mndTransDrop(pTrans);
  return code;
}

static int32_t mndDropFunc(SMnode *pMnode, SRpcMsg *pReq, SFuncObj *pFunc) {
  int32_t code = -1;
  STrans *pTrans = mndTransCreate(pMnode, TRN_POLICY_ROLLBACK, TRN_CONFLICT_NOTHING, pReq, "drop-func");
  if (pTrans == NULL) goto _OVER;

  mInfo("trans:%d, used to drop user:%s", pTrans->id, pFunc->name);

  SSdbRaw *pRedoRaw = mndFuncActionEncode(pFunc);
  if (pRedoRaw == NULL) goto _OVER;
  if (mndTransAppendRedolog(pTrans, pRedoRaw) != 0) goto _OVER;
  (void)sdbSetRawStatus(pRedoRaw, SDB_STATUS_DROPPING);

  SSdbRaw *pUndoRaw = mndFuncActionEncode(pFunc);
  if (pUndoRaw == NULL) goto _OVER;
  if (mndTransAppendUndolog(pTrans, pUndoRaw) != 0) goto _OVER;
  (void)sdbSetRawStatus(pUndoRaw, SDB_STATUS_READY);

  SSdbRaw *pCommitRaw = mndFuncActionEncode(pFunc);
  if (pCommitRaw == NULL) goto _OVER;
  if (mndTransAppendCommitlog(pTrans, pCommitRaw) != 0) goto _OVER;
  (void)sdbSetRawStatus(pCommitRaw, SDB_STATUS_DROPPED);

  if (mndTransPrepare(pMnode, pTrans) != 0) goto _OVER;

  code = 0;

_OVER:
  mndTransDrop(pTrans);
  return code;
}

static int32_t mndProcessCreateFuncReq(SRpcMsg *pReq) {
  SMnode        *pMnode = pReq->info.node;
  int32_t        code = -1;
  SFuncObj      *pFunc = NULL;
  SCreateFuncReq createReq = {0};

  if (tDeserializeSCreateFuncReq(pReq->pCont, pReq->contLen, &createReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    goto _OVER;
  }
#ifdef WINDOWS
  terrno = TSDB_CODE_MND_INVALID_PLATFORM;
  goto _OVER;
#endif
  mInfo("func:%s, start to create, size:%d", createReq.name, createReq.codeLen);
  if (mndCheckOperPrivilege(pMnode, pReq->info.conn.user, MND_OPER_CREATE_FUNC) != 0) {
    goto _OVER;
  }

  pFunc = mndAcquireFunc(pMnode, createReq.name);
  if (pFunc != NULL) {
    if (createReq.igExists) {
      mInfo("func:%s, already exist, ignore exist is set", createReq.name);
      code = 0;
      goto _OVER;
    } else if (createReq.orReplace) {
      mInfo("func:%s, replace function is set", createReq.name);
      code = 0;
    } else {
      terrno = TSDB_CODE_MND_FUNC_ALREADY_EXIST;
      goto _OVER;
    }
  } else if (terrno == TSDB_CODE_MND_FUNC_ALREADY_EXIST) {
    goto _OVER;
  }

  if (createReq.name[0] == 0) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_NAME;
    goto _OVER;
  }

  if (createReq.pCode == NULL) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_CODE;
    goto _OVER;
  }

  if (createReq.codeLen <= 1) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_CODE;
    goto _OVER;
  }

  if (createReq.bufSize < 0 || createReq.bufSize > TSDB_FUNC_BUF_SIZE) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_BUFSIZE;
    goto _OVER;
  }

  code = mndCreateFunc(pMnode, pReq, &createReq);
  if (code == 0) code = TSDB_CODE_ACTION_IN_PROGRESS;

_OVER:
  if (code != 0 && code != TSDB_CODE_ACTION_IN_PROGRESS) {
    mError("func:%s, failed to create since %s", createReq.name, terrstr());
  }

  mndReleaseFunc(pMnode, pFunc);
  tFreeSCreateFuncReq(&createReq);
  return code;
}

static int32_t mndProcessDropFuncReq(SRpcMsg *pReq) {
  SMnode      *pMnode = pReq->info.node;
  int32_t      code = -1;
  SFuncObj    *pFunc = NULL;
  SDropFuncReq dropReq = {0};

  if (tDeserializeSDropFuncReq(pReq->pCont, pReq->contLen, &dropReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    goto _OVER;
  }

  mInfo("func:%s, start to drop", dropReq.name);
  if (mndCheckOperPrivilege(pMnode, pReq->info.conn.user, MND_OPER_DROP_FUNC) != 0) {
    goto _OVER;
  }

  if (dropReq.name[0] == 0) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_NAME;
    goto _OVER;
  }

  pFunc = mndAcquireFunc(pMnode, dropReq.name);
  if (pFunc == NULL) {
    if (dropReq.igNotExists) {
      mInfo("func:%s, not exist, ignore not exist is set", dropReq.name);
      code = 0;
      goto _OVER;
    } else {
      terrno = TSDB_CODE_MND_FUNC_NOT_EXIST;
      goto _OVER;
    }
  }

  code = mndDropFunc(pMnode, pReq, pFunc);
  if (code == 0) code = TSDB_CODE_ACTION_IN_PROGRESS;

_OVER:
  if (code != 0 && code != TSDB_CODE_ACTION_IN_PROGRESS) {
    mError("func:%s, failed to drop since %s", dropReq.name, terrstr());
  }

  mndReleaseFunc(pMnode, pFunc);
  return code;
}

static int32_t mndProcessRetrieveFuncReq(SRpcMsg *pReq) {
  SMnode          *pMnode = pReq->info.node;
  int32_t          code = -1;
  SRetrieveFuncReq retrieveReq = {0};
  SRetrieveFuncRsp retrieveRsp = {0};

  if (tDeserializeSRetrieveFuncReq(pReq->pCont, pReq->contLen, &retrieveReq) != 0) {
    terrno = TSDB_CODE_INVALID_MSG;
    goto RETRIEVE_FUNC_OVER;
  }

  if (retrieveReq.numOfFuncs <= 0 || retrieveReq.numOfFuncs > TSDB_FUNC_MAX_RETRIEVE) {
    terrno = TSDB_CODE_MND_INVALID_FUNC_RETRIEVE;
    goto RETRIEVE_FUNC_OVER;
  }

  retrieveRsp.numOfFuncs = retrieveReq.numOfFuncs;
  retrieveRsp.pFuncInfos = taosArrayInit(retrieveReq.numOfFuncs, sizeof(SFuncInfo));
  if (retrieveRsp.pFuncInfos == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    goto RETRIEVE_FUNC_OVER;
  }

  retrieveRsp.pFuncExtraInfos = taosArrayInit(retrieveReq.numOfFuncs, sizeof(SFuncExtraInfo));
  if (retrieveRsp.pFuncExtraInfos == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    goto RETRIEVE_FUNC_OVER;
  }

  for (int32_t i = 0; i < retrieveReq.numOfFuncs; ++i) {
    char *funcName = taosArrayGet(retrieveReq.pFuncNames, i);

    SFuncObj *pFunc = mndAcquireFunc(pMnode, funcName);
    if (pFunc == NULL) {
      goto RETRIEVE_FUNC_OVER;
    }

    SFuncInfo funcInfo = {0};
    memcpy(funcInfo.name, pFunc->name, TSDB_FUNC_NAME_LEN);
    funcInfo.funcType = pFunc->funcType;
    funcInfo.scriptType = pFunc->scriptType;
    funcInfo.outputType = pFunc->outputType;
    funcInfo.outputLen = pFunc->outputLen;
    funcInfo.bufSize = pFunc->bufSize;
    funcInfo.signature = pFunc->signature;
    if (retrieveReq.ignoreCodeComment) {
      funcInfo.commentSize = 0;
      funcInfo.codeSize = 0;
    } else {
      funcInfo.commentSize = pFunc->commentSize;
      funcInfo.codeSize = pFunc->codeSize;
      funcInfo.pCode = taosMemoryCalloc(1, funcInfo.codeSize);
      if (funcInfo.pCode == NULL) {
        terrno = TSDB_CODE_OUT_OF_MEMORY;
        goto RETRIEVE_FUNC_OVER;
      }
      memcpy(funcInfo.pCode, pFunc->pCode, pFunc->codeSize);
      if (funcInfo.commentSize > 0) {
        funcInfo.pComment = taosMemoryCalloc(1, funcInfo.commentSize);
        if (funcInfo.pComment == NULL) {
          terrno = TSDB_CODE_OUT_OF_MEMORY;
          goto RETRIEVE_FUNC_OVER;
        }
        memcpy(funcInfo.pComment, pFunc->pComment, pFunc->commentSize);
      }
    }
    taosArrayPush(retrieveRsp.pFuncInfos, &funcInfo);
    SFuncExtraInfo extraInfo = {0};
    extraInfo.funcVersion = pFunc->funcVersion;
    extraInfo.funcCreatedTime = pFunc->createdTime;
    taosArrayPush(retrieveRsp.pFuncExtraInfos, &extraInfo);

    mndReleaseFunc(pMnode, pFunc);
  }

  int32_t contLen = tSerializeSRetrieveFuncRsp(NULL, 0, &retrieveRsp);
  void   *pRsp = rpcMallocCont(contLen);
  if (pRsp == NULL) {
    terrno = TSDB_CODE_OUT_OF_MEMORY;
    goto RETRIEVE_FUNC_OVER;
  }

  tSerializeSRetrieveFuncRsp(pRsp, contLen, &retrieveRsp);

  pReq->info.rsp = pRsp;
  pReq->info.rspLen = contLen;

  code = 0;

RETRIEVE_FUNC_OVER:
  tFreeSRetrieveFuncReq(&retrieveReq);
  tFreeSRetrieveFuncRsp(&retrieveRsp);

  return code;
}

static void *mnodeGenTypeStr(char *buf, int32_t buflen, uint8_t type, int32_t len) {
  char *msg = "unknown";
  if (type >= sizeof(tDataTypes) / sizeof(tDataTypes[0])) {
    return msg;
  }

  if (type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BINARY || type == TSDB_DATA_TYPE_GEOMETRY) {
    int32_t bytes = len > 0 ? (int32_t)(len - VARSTR_HEADER_SIZE) : len;

    snprintf(buf, buflen - 1, "%s(%d)", tDataTypes[type].name, type == TSDB_DATA_TYPE_NCHAR ? bytes / 4 : bytes);
    buf[buflen - 1] = 0;

    return buf;
  }

  return tDataTypes[type].name;
}

static int32_t mndRetrieveFuncs(SRpcMsg *pReq, SShowObj *pShow, SSDataBlock *pBlock, int32_t rows) {
  SMnode   *pMnode = pReq->info.node;
  SSdb     *pSdb = pMnode->pSdb;
  int32_t   numOfRows = 0;
  SFuncObj *pFunc = NULL;
  int32_t   cols = 0;
  char      buf[TSDB_TYPE_STR_MAX_LEN];

  while (numOfRows < rows) {
    pShow->pIter = sdbFetch(pSdb, SDB_FUNC, pShow->pIter, (void **)&pFunc);
    if (pShow->pIter == NULL) break;

    cols = 0;

    char b1[tListLen(pFunc->name) + VARSTR_HEADER_SIZE] = {0};
    STR_WITH_MAXSIZE_TO_VARSTR(b1, pFunc->name, pShow->pMeta->pSchemas[cols].bytes);

    SColumnInfoData *pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)b1, false);

    if (pFunc->pComment) {
      char *b2 = taosMemoryCalloc(1, pShow->pMeta->pSchemas[cols].bytes);
      STR_WITH_MAXSIZE_TO_VARSTR(b2, pFunc->pComment, pShow->pMeta->pSchemas[cols].bytes);

      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
      colDataSetVal(pColInfo, numOfRows, (const char *)b2, false);
      taosMemoryFree(b2);
    } else {
      pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
      colDataSetVal(pColInfo, numOfRows, NULL, true);
    }

    int32_t isAgg = (pFunc->funcType == TSDB_FUNC_TYPE_AGGREGATE) ? 1 : 0;

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)&isAgg, false);

    char b3[TSDB_TYPE_STR_MAX_LEN + 1] = {0};
    STR_WITH_MAXSIZE_TO_VARSTR(b3, mnodeGenTypeStr(buf, TSDB_TYPE_STR_MAX_LEN, pFunc->outputType, pFunc->outputLen),
                               pShow->pMeta->pSchemas[cols].bytes);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)b3, false);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)&pFunc->createdTime, false);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)&pFunc->codeSize, false);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)&pFunc->bufSize, false);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    char *language = "";
    if (pFunc->scriptType == TSDB_FUNC_SCRIPT_BIN_LIB) {
      language = "C";
    } else if (pFunc->scriptType == TSDB_FUNC_SCRIPT_PYTHON) {
      language = "Python";
    }
    char varLang[TSDB_TYPE_STR_MAX_LEN + 1] = {0};
    varDataSetLen(varLang, strlen(language));
    strcpy(varDataVal(varLang), language);
    colDataSetVal(pColInfo, numOfRows, (const char *)varLang, false);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    int32_t varCodeLen = (pFunc->codeSize + VARSTR_HEADER_SIZE) > TSDB_MAX_BINARY_LEN
                             ? TSDB_MAX_BINARY_LEN
                             : pFunc->codeSize + VARSTR_HEADER_SIZE;
    char   *b4 = taosMemoryMalloc(varCodeLen);
    memcpy(varDataVal(b4), pFunc->pCode, varCodeLen - VARSTR_HEADER_SIZE);
    varDataSetLen(b4, varCodeLen - VARSTR_HEADER_SIZE);
    colDataSetVal(pColInfo, numOfRows, (const char *)b4, false);
    taosMemoryFree(b4);

    pColInfo = taosArrayGet(pBlock->pDataBlock, cols++);
    colDataSetVal(pColInfo, numOfRows, (const char *)&pFunc->funcVersion, false);

    numOfRows++;
    sdbRelease(pSdb, pFunc);
  }

  pShow->numOfRows += numOfRows;
  return numOfRows;
}

static void mndCancelGetNextFunc(SMnode *pMnode, void *pIter) {
  SSdb *pSdb = pMnode->pSdb;
  sdbCancelFetch(pSdb, pIter);
}