/*
 * 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 "os.h"
#include "tgrant.h"
#include "tbalance.h"
#include "tglobalcfg.h"
#include "ttime.h"
#include "tutil.h"
#include "tsocket.h"
#include "dnode.h"
#include "mgmtDef.h"
#include "mgmtLog.h"
#include "mgmtDClient.h"
#include "mgmtDServer.h"
#include "mgmtDnode.h"
#include "mgmtMnode.h"
#include "mgmtSdb.h"
#include "mgmtShell.h"
#include "mgmtUser.h"
#include "mgmtVgroup.h"

void   *tsDnodeSdb = NULL;
int32_t tsDnodeUpdateSize = 0;
extern void *  tsVgroupSdb;

static int32_t mgmtCreateDnode(uint32_t ip);
static void    mgmtProcessCreateDnodeMsg(SQueuedMsg *pMsg);
static void    mgmtProcessDropDnodeMsg(SQueuedMsg *pMsg);
static void    mgmtProcessCfgDnodeMsg(SQueuedMsg *pMsg);
static void    mgmtProcessCfgDnodeMsgRsp(SRpcMsg *rpcMsg) ;
static void    mgmtProcessDnodeStatusMsg(SRpcMsg *rpcMsg);
static int32_t mgmtGetModuleMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mgmtRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mgmtGetConfigMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mgmtRetrieveConfigs(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mgmtGetVnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mgmtRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);
static int32_t mgmtGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
static int32_t mgmtRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn);

static int32_t mgmtDnodeActionDestroy(SSdbOper *pOper) {
  tfree(pOper->pObj);
  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionInsert(SSdbOper *pOper) {
  SDnodeObj *pDnode = pOper->pObj;
  if (pDnode->status != TAOS_DN_STATUS_DROPPING) {
    pDnode->status = TAOS_DN_STATUS_OFFLINE;
  }

  pDnode->mnodeShellPort = tsMnodeShellPort;
  pDnode->mnodeDnodePort = tsMnodeDnodePort;
  pDnode->dnodeShellPort = tsDnodeShellPort;
  pDnode->dnodeMnodePort = tsDnodeMnodePort;
  pDnode->syncPort       = 0;

  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionDelete(SSdbOper *pOper) {
  SDnodeObj *pDnode = pOper->pObj;
  void *     pNode = NULL;
  void *     pLastNode = NULL;
  SVgObj *   pVgroup = NULL;
  int32_t    numOfVgroups = 0;

  while (1) {
    pLastNode = pNode;
    pNode = sdbFetchRow(tsVgroupSdb, pNode, (void **)&pVgroup);
    if (pVgroup == NULL) break;

    if (pVgroup->vnodeGid[0].dnodeId == pDnode->dnodeId) {
      SSdbOper oper = {
        .type = SDB_OPER_LOCAL,
        .table = tsVgroupSdb,
        .pObj = pVgroup,
      };
      sdbDeleteRow(&oper);
      pNode = pLastNode;
      numOfVgroups++;
      continue;
    }
  }

  mTrace("dnode:%d, all vgroups:%d is dropped from sdb", pDnode->dnodeId, numOfVgroups);
  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionUpdate(SSdbOper *pOper) {
  SDnodeObj *pDnode = pOper->pObj;
  SDnodeObj *pSaved = mgmtGetDnode(pDnode->dnodeId);
  if (pDnode != pSaved) {
    memcpy(pSaved, pDnode, pOper->rowSize);
    free(pDnode);
  }
  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionEncode(SSdbOper *pOper) {
  SDnodeObj *pDnode = pOper->pObj;
  memcpy(pOper->rowData, pDnode, tsDnodeUpdateSize);
  pOper->rowSize = tsDnodeUpdateSize;
  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionDecode(SSdbOper *pOper) {
  SDnodeObj *pDnode = (SDnodeObj *) calloc(1, sizeof(SDnodeObj));
  if (pDnode == NULL) return TSDB_CODE_SERV_OUT_OF_MEMORY;

  memcpy(pDnode, pOper->rowData, tsDnodeUpdateSize);
  pOper->pObj = pDnode;
  return TSDB_CODE_SUCCESS;
}

static int32_t mgmtDnodeActionRestored() {
  int32_t numOfRows = sdbGetNumOfRows(tsDnodeSdb);
  if (numOfRows <= 0 && dnodeIsFirstDeploy()) {
    uint32_t ip = inet_addr(tsPrivateIp);
    mgmtCreateDnode(ip);
    SDnodeObj *pDnode = mgmtGetDnodeByIp(ip);
    mgmtAddMnode(pDnode->dnodeId);
    mgmtReleaseDnode(pDnode);
  }

  return TSDB_CODE_SUCCESS;
}

int32_t mgmtInitDnodes() {
  SDnodeObj tObj;
  tsDnodeUpdateSize = (int8_t *)tObj.updateEnd - (int8_t *)&tObj;

  SSdbTableDesc tableDesc = {
    .tableId      = SDB_TABLE_DNODE,
    .tableName    = "dnodes",
    .hashSessions = TSDB_MAX_DNODES,
    .maxRowSize   = tsDnodeUpdateSize,
    .refCountPos  = (int8_t *)(&tObj.refCount) - (int8_t *)&tObj,
    .keyType      = SDB_KEY_AUTO,
    .insertFp     = mgmtDnodeActionInsert,
    .deleteFp     = mgmtDnodeActionDelete,
    .updateFp     = mgmtDnodeActionUpdate,
    .encodeFp     = mgmtDnodeActionEncode,
    .decodeFp     = mgmtDnodeActionDecode,
    .destroyFp    = mgmtDnodeActionDestroy,
    .restoredFp   = mgmtDnodeActionRestored
  };

  tsDnodeSdb = sdbOpenTable(&tableDesc);
  if (tsDnodeSdb == NULL) {
    mError("failed to init dnodes data");
    return -1;
  }

  mgmtAddShellMsgHandle(TSDB_MSG_TYPE_CM_CREATE_DNODE, mgmtProcessCreateDnodeMsg);
  mgmtAddShellMsgHandle(TSDB_MSG_TYPE_CM_DROP_DNODE, mgmtProcessDropDnodeMsg); 
  mgmtAddShellMsgHandle(TSDB_MSG_TYPE_CM_CONFIG_DNODE, mgmtProcessCfgDnodeMsg);
  mgmtAddDClientRspHandle(TSDB_MSG_TYPE_MD_CONFIG_DNODE_RSP, mgmtProcessCfgDnodeMsgRsp);
  mgmtAddDServerMsgHandle(TSDB_MSG_TYPE_DM_STATUS, mgmtProcessDnodeStatusMsg);
  mgmtAddShellShowMetaHandle(TSDB_MGMT_TABLE_MODULE, mgmtGetModuleMeta);
  mgmtAddShellShowRetrieveHandle(TSDB_MGMT_TABLE_MODULE, mgmtRetrieveModules);
  mgmtAddShellShowMetaHandle(TSDB_MGMT_TABLE_CONFIGS, mgmtGetConfigMeta);
  mgmtAddShellShowRetrieveHandle(TSDB_MGMT_TABLE_CONFIGS, mgmtRetrieveConfigs);
  mgmtAddShellShowMetaHandle(TSDB_MGMT_TABLE_VNODES, mgmtGetVnodeMeta);
  mgmtAddShellShowRetrieveHandle(TSDB_MGMT_TABLE_VNODES, mgmtRetrieveVnodes);
  mgmtAddShellShowMetaHandle(TSDB_MGMT_TABLE_DNODE, mgmtGetDnodeMeta);
  mgmtAddShellShowRetrieveHandle(TSDB_MGMT_TABLE_DNODE, mgmtRetrieveDnodes);
 
  mTrace("table:dnodes table is created");
  return 0;
}

void mgmtCleanupDnodes() {
  sdbCloseTable(tsDnodeSdb);
}

void *mgmtGetNextDnode(void *pNode, SDnodeObj **pDnode) { 
  return sdbFetchRow(tsDnodeSdb, pNode, (void **)pDnode); 
}

int32_t mgmtGetDnodesNum() {
  return sdbGetNumOfRows(tsDnodeSdb);
}

void *mgmtGetDnode(int32_t dnodeId) {
  return sdbGetRow(tsDnodeSdb, &dnodeId);
}

void *mgmtGetDnodeByIp(uint32_t ip) {
  SDnodeObj *pDnode = NULL;
  void *     pNode = NULL;

  while (1) {
    pNode = sdbFetchRow(tsDnodeSdb, pNode, (void**)&pDnode);
    if (pDnode == NULL) break;
    if (ip == pDnode->privateIp) {
      return pDnode;
    }
    mgmtReleaseDnode(pDnode);
  }

  return NULL;
}

void mgmtReleaseDnode(SDnodeObj *pDnode) {
  sdbDecRef(tsDnodeSdb, pDnode);
}

void mgmtUpdateDnode(SDnodeObj *pDnode) {
  SSdbOper oper = {
    .type = SDB_OPER_GLOBAL,
    .table = tsDnodeSdb,
    .pObj = pDnode,
    .rowSize = tsDnodeUpdateSize
  };

  sdbUpdateRow(&oper);
}

void mgmtProcessCfgDnodeMsg(SQueuedMsg *pMsg) {
  SRpcMsg rpcRsp = {.handle = pMsg->thandle, .pCont = NULL, .contLen = 0, .code = 0, .msgType = 0};
  
  SCMCfgDnodeMsg *pCmCfgDnode = pMsg->pCont;
  if (pCmCfgDnode->ip[0] == 0) {
    strcpy(pCmCfgDnode->ip, tsPrivateIp);
  } else {
    strcpy(pCmCfgDnode->ip, pCmCfgDnode->ip);
  }
  uint32_t dnodeIp = inet_addr(pCmCfgDnode->ip);

  if (strcmp(pMsg->pUser->pAcct->user, "root") != 0) {
    rpcRsp.code = TSDB_CODE_NO_RIGHTS;
  } else {
    SRpcIpSet ipSet = mgmtGetIpSetFromIp(dnodeIp);
    SMDCfgDnodeMsg *pMdCfgDnode = rpcMallocCont(sizeof(SMDCfgDnodeMsg));
    strcpy(pMdCfgDnode->ip, pCmCfgDnode->ip);
    strcpy(pMdCfgDnode->config, pCmCfgDnode->config);
    SRpcMsg rpcMdCfgDnodeMsg = {
        .handle = 0,
        .code = 0,
        .msgType = TSDB_MSG_TYPE_MD_CONFIG_DNODE,
        .pCont = pMdCfgDnode,
        .contLen = sizeof(SMDCfgDnodeMsg)
    };
    mgmtSendMsgToDnode(&ipSet, &rpcMdCfgDnodeMsg);
    rpcRsp.code = TSDB_CODE_SUCCESS;
  }

  if (rpcRsp.code == TSDB_CODE_SUCCESS) {
    mPrint("dnode:%s, is configured by %s", pCmCfgDnode->ip, pMsg->pUser->user);
  }

  rpcSendResponse(&rpcRsp);
}

static void mgmtProcessCfgDnodeMsgRsp(SRpcMsg *rpcMsg) {
  mPrint("cfg vnode rsp is received, result:%s", tstrerror(rpcMsg->code));
}

void mgmtProcessDnodeStatusMsg(SRpcMsg *rpcMsg) {
  SDMStatusMsg *pStatus = rpcMsg->pCont;
  pStatus->dnodeId = htonl(pStatus->dnodeId);
  pStatus->privateIp = htonl(pStatus->privateIp);
  pStatus->publicIp = htonl(pStatus->publicIp);
  pStatus->moduleStatus = htonl(pStatus->moduleStatus);
  pStatus->lastReboot = htonl(pStatus->lastReboot);
  pStatus->numOfCores = htons(pStatus->numOfCores);
  pStatus->numOfTotalVnodes = htons(pStatus->numOfTotalVnodes);

  uint32_t version = htonl(pStatus->version);
  if (version != tsVersion) {
    mError("status msg version:%d not equal with mnode:%d", version, tsVersion);
    mgmtSendSimpleResp(rpcMsg->handle, TSDB_CODE_INVALID_MSG_VERSION);
    return ;
  }

  SDnodeObj *pDnode = NULL;
  if (pStatus->dnodeId == 0) {
    pDnode = mgmtGetDnodeByIp(pStatus->privateIp);
    if (pDnode == NULL) {
      mTrace("dnode not created, privateIp:%s", taosIpStr(pStatus->privateIp));
      mgmtSendSimpleResp(rpcMsg->handle, TSDB_CODE_DNODE_NOT_EXIST);
      return;
    }
  } else {
    pDnode = mgmtGetDnode(pStatus->dnodeId);
    if (pDnode == NULL) {
      mError("dnode:%d, not exist, privateIp:%s", pStatus->dnodeId, taosIpStr(pStatus->privateIp));
      mgmtSendSimpleResp(rpcMsg->handle, TSDB_CODE_DNODE_NOT_EXIST);
      return;
    }
  }
  
  pDnode->privateIp        = pStatus->privateIp;
  pDnode->publicIp         = pStatus->publicIp;
  pDnode->lastReboot       = pStatus->lastReboot;
  pDnode->numOfCores       = pStatus->numOfCores;
  pDnode->diskAvailable    = pStatus->diskAvailable;
  pDnode->alternativeRole  = pStatus->alternativeRole;
  pDnode->totalVnodes      = pStatus->numOfTotalVnodes; 
  pDnode->moduleStatus     = pStatus->moduleStatus;
  
  if (pStatus->dnodeId == 0) {
    mTrace("dnode:%d, first access, privateIp:%s, name:%s", pDnode->dnodeId, taosIpStr(pDnode->privateIp), pDnode->dnodeName);
  }
 
  int32_t openVnodes = htons(pStatus->openVnodes);
  for (int32_t j = 0; j < openVnodes; ++j) {
    SVnodeLoad *pVload = &pStatus->load[j];
    pDnode->vload[j].vgId          = htonl(pVload->vgId);
    pDnode->vload[j].totalStorage  = htobe64(pVload->totalStorage);
    pDnode->vload[j].compStorage   = htobe64(pVload->compStorage);
    pDnode->vload[j].pointsWritten = htobe64(pVload->pointsWritten);
    
    SVgObj *pVgroup = mgmtGetVgroup(pDnode->vload[j].vgId);
    if (pVgroup == NULL) {
      SRpcIpSet ipSet = mgmtGetIpSetFromIp(pDnode->privateIp);
      mPrint("dnode:%d, vgroup:%d not exist in mnode, drop it", pDnode->dnodeId, pDnode->vload[j].vgId);
      mgmtSendDropVnodeMsg(pDnode->vload[j].vgId, &ipSet, NULL);
    } else {
      mgmtUpdateVgroupStatus(pVgroup, pDnode->dnodeId, pVload);
      mgmtReleaseVgroup(pVgroup);
    }
  }

  if (pDnode->status == TAOS_DN_STATUS_OFFLINE) {
    mTrace("dnode:%d, from offline to online", pDnode->dnodeId);
    pDnode->status = TAOS_DN_STATUS_READY;
    balanceNotify();
  }

  mgmtReleaseDnode(pDnode);

  int32_t contLen = sizeof(SDMStatusRsp) + TSDB_MAX_VNODES * sizeof(SVnodeAccess);
  SDMStatusRsp *pRsp = rpcMallocCont(contLen);
  if (pRsp == NULL) {
    mgmtSendSimpleResp(rpcMsg->handle, TSDB_CODE_SERV_OUT_OF_MEMORY);
    return;
  }

  mgmtGetMnodeList(&pRsp->mnodes);

  pRsp->dnodeState.dnodeId = htonl(pDnode->dnodeId);
  pRsp->dnodeState.moduleStatus = htonl((int32_t)pDnode->isMgmt);
  pRsp->dnodeState.createdTime  = htonl(pDnode->createdTime / 1000);
  pRsp->dnodeState.numOfVnodes = 0;
  
  contLen = sizeof(SDMStatusRsp);

  //TODO: set vnode access
  
  SRpcMsg rpcRsp = {
    .handle  = rpcMsg->handle,
    .code    = TSDB_CODE_SUCCESS,
    .pCont   = pRsp,
    .contLen = contLen
  };

  rpcSendResponse(&rpcRsp);
}

static int32_t mgmtCreateDnode(uint32_t ip) {
  int32_t grantCode = grantCheck(TSDB_GRANT_DNODE);
  if (grantCode != TSDB_CODE_SUCCESS) {
    return grantCode;
  }

  SDnodeObj *pDnode = mgmtGetDnodeByIp(ip);
  if (pDnode != NULL) {
    mError("dnode:%d is alredy exist, ip:%s", pDnode->dnodeId, taosIpStr(pDnode->privateIp));
    return TSDB_CODE_DNODE_ALREADY_EXIST;
  }

  pDnode = (SDnodeObj *) calloc(1, sizeof(SDnodeObj));
  pDnode->privateIp = ip;
  pDnode->publicIp = ip;
  pDnode->createdTime = taosGetTimestampMs();
  pDnode->status = TAOS_DN_STATUS_OFFLINE; 
  pDnode->totalVnodes = TSDB_INVALID_VNODE_NUM; 
  sprintf(pDnode->dnodeName, "n%d", sdbGetId(tsDnodeSdb) + 1);

  SSdbOper oper = {
    .type = SDB_OPER_GLOBAL,
    .table = tsDnodeSdb,
    .pObj = pDnode,
    .rowSize = sizeof(SDnodeObj)
  };

  int32_t code = sdbInsertRow(&oper);
  if (code != TSDB_CODE_SUCCESS) {
    int dnodeId = pDnode->dnodeId;
    tfree(pDnode);
    mError("failed to create dnode:%d, result:%s", dnodeId, tstrerror(code));
    return TSDB_CODE_SDB_ERROR;
  }

  mPrint("dnode:%d is created, result:%s", pDnode->dnodeId, tstrerror(code));
  return code;
}

int32_t mgmtDropDnode(SDnodeObj *pDnode) {
  SSdbOper oper = {
    .type = SDB_OPER_GLOBAL,
    .table = tsDnodeSdb,
    .pObj = pDnode
  };

  int32_t code = sdbDeleteRow(&oper); 
  if (code != TSDB_CODE_SUCCESS) {
    code = TSDB_CODE_SDB_ERROR;
  }

  mLPrint("dnode:%d is dropped from cluster, result:%s", pDnode->dnodeId, tstrerror(code));
  return code;
}

static int32_t mgmtDropDnodeByIp(uint32_t ip) {
  SDnodeObj *pDnode = mgmtGetDnodeByIp(ip);
  if (pDnode == NULL) {
    mError("dnode:%s, is not exist", taosIpStr(ip));
    return TSDB_CODE_INVALID_VALUE;
  }

  if (pDnode->privateIp == dnodeGetMnodeMasteIp()) {
    mError("dnode:%d, can't drop dnode which is master", pDnode->dnodeId);
    return TSDB_CODE_NO_REMOVE_MASTER;
  }

#ifndef _VPEER
  return mgmtDropDnode(pDnode);
#else
  return balanceDropDnode(pDnode);
#endif
}

static void mgmtProcessCreateDnodeMsg(SQueuedMsg *pMsg) {
  SRpcMsg rpcRsp = {.handle = pMsg->thandle, .pCont = NULL, .contLen = 0, .code = 0, .msgType = 0};
  
  SCMCreateDnodeMsg *pCreate = pMsg->pCont;

  if (strcmp(pMsg->pUser->pAcct->user, "root") != 0) {
    rpcRsp.code = TSDB_CODE_NO_RIGHTS;
  } else {
    uint32_t ip = inet_addr(pCreate->ip);
    rpcRsp.code = mgmtCreateDnode(ip);
    if (rpcRsp.code == TSDB_CODE_SUCCESS) {
      SDnodeObj *pDnode = mgmtGetDnodeByIp(ip);
      mLPrint("dnode:%d, ip:%s is created by %s", pDnode->dnodeId, pCreate->ip, pMsg->pUser->user);
    } else {
      mError("failed to create dnode:%s, reason:%s", pCreate->ip, tstrerror(rpcRsp.code));
    }
  }
  rpcSendResponse(&rpcRsp);
}


static void mgmtProcessDropDnodeMsg(SQueuedMsg *pMsg) {
  SRpcMsg rpcRsp = {.handle = pMsg->thandle, .pCont = NULL, .contLen = 0, .code = 0, .msgType = 0};
  
  SCMDropDnodeMsg *pDrop = pMsg->pCont;
  if (strcmp(pMsg->pUser->pAcct->user, "root") != 0) {
    rpcRsp.code = TSDB_CODE_NO_RIGHTS;
  } else {
    uint32_t ip = inet_addr(pDrop->ip);
    rpcRsp.code = mgmtDropDnodeByIp(ip);
    if (rpcRsp.code == TSDB_CODE_SUCCESS) {
      mLPrint("dnode:%s is dropped by %s", pDrop->ip, pMsg->pUser->user);
    } else {
      mError("failed to drop dnode:%s, reason:%s", pDrop->ip, tstrerror(rpcRsp.code));
    }
  }

  rpcSendResponse(&rpcRsp);
}

static int32_t mgmtGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  SUserObj *pUser = mgmtGetUserFromConn(pConn, NULL);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->pAcct->user, "root") != 0) return TSDB_CODE_NO_RIGHTS;

  int32_t  cols = 0;
  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "id");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 16;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "private ip");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 16;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "public ip");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
  strcpy(pSchema[cols].name, "create time");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 10;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "open vnodes");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "total vnodes");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

#ifdef _VPEER
  pShow->bytes[cols] = 18;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "balance");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;
#endif  

  pMeta->numOfColumns = htons(cols);
  pShow->numOfColumns = cols;

  pShow->offset[0] = 0;
  for (int32_t i = 1; i < cols; ++i) {
    pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];
  }

  pShow->numOfRows = mgmtGetDnodesNum();
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pNode = NULL;

  mgmtReleaseUser(pUser);

  return 0;
}

static int32_t mgmtRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t    numOfRows = 0;
  int32_t    cols      = 0;
  SDnodeObj *pDnode   = NULL;
  char      *pWrite;
  char       ipstr[32];

  while (numOfRows < rows) {
    pShow->pNode = mgmtGetNextDnode(pShow->pNode, &pDnode);
    if (pDnode == NULL) break;

    cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->dnodeId;
    cols++;

    tinet_ntoa(ipstr, pDnode->privateIp);
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    strcpy(pWrite, ipstr);
    cols++;

    tinet_ntoa(ipstr, pDnode->publicIp);
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    strcpy(pWrite, ipstr);
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int64_t *)pWrite = pDnode->createdTime;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    strcpy(pWrite, mgmtGetDnodeStatusStr(pDnode->status));
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->openVnodes;
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    *(int16_t *)pWrite = pDnode->totalVnodes;
    cols++;

#ifdef _VPEER
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    strcpy(pWrite, mgmtGetDnodeStatusStr(pDnode->status));
    cols++;
#endif    

    numOfRows++;
    mgmtReleaseDnode(pDnode);
  }

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

static bool mgmtCheckModuleInDnode(SDnodeObj *pDnode, int32_t moduleType) {
  uint32_t status = pDnode->moduleStatus & (1 << moduleType);
  return status > 0;
}

static int32_t mgmtGetModuleMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;

  SUserObj *pUser = mgmtGetUserFromConn(pConn, NULL);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_NO_RIGHTS;

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 2;
  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
  strcpy(pSchema[cols].name, "id");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 16;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "ip");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "module");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  pShow->numOfColumns = cols;

  pShow->offset[0] = 0;
  for (int32_t i = 1; i < cols; ++i) {
    pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];
  }

  pShow->numOfRows = mgmtGetDnodesNum() * TSDB_MOD_MAX;
  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pNode = NULL;
  mgmtReleaseUser(pUser);

  return 0;
}

int32_t mgmtRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t numOfRows = 0;
  char *  pWrite;

  while (numOfRows < rows) {
    SDnodeObj *pDnode = NULL;
    pShow->pNode = mgmtGetNextDnode(pShow->pNode, (SDnodeObj **)&pDnode);
    if (pDnode == NULL) break;

    for (int32_t moduleType = 0; moduleType < TSDB_MOD_MAX; ++moduleType) {
      int32_t cols = 0;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int16_t *)pWrite = pDnode->dnodeId;
      cols++;

      char ipstr[20];
      tinet_ntoa(ipstr, pDnode->privateIp);
      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      strcpy(pWrite, ipstr);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      switch (moduleType) {
        case TSDB_MOD_MGMT:
          strcpy(pWrite, "mgmt");
          break;
        case TSDB_MOD_HTTP:
          strcpy(pWrite, "http");
          break;
        case TSDB_MOD_MONITOR:
          strcpy(pWrite, "monitor");
          break;
        default:
          strcpy(pWrite, "unknown");
      }
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      bool enable = mgmtCheckModuleInDnode(pDnode, moduleType);
      strcpy(pWrite, enable ? "enable" : "disable");
      cols++;

      numOfRows++;
    }

    mgmtReleaseDnode(pDnode);
  }

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

static bool mgmtCheckConfigShow(SGlobalConfig *cfg) {
  if (!(cfg->cfgType & TSDB_CFG_CTYPE_B_SHOW))
    return false;
  return true;
}

static int32_t mgmtGetConfigMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;

  SUserObj *pUser = mgmtGetUserFromConn(pConn, NULL);
  if (pUser == NULL) return 0;

  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_NO_RIGHTS;

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = TSDB_CFG_OPTION_LEN;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "config name");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = TSDB_CFG_VALUE_LEN;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "config value");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  pShow->numOfColumns = cols;

  pShow->offset[0] = 0;
  for (int32_t i = 1; i < cols; ++i) pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];

  pShow->numOfRows = 0;
  for (int32_t i = tsGlobalConfigNum - 1; i >= 0; --i) {
    SGlobalConfig *cfg = tsGlobalConfig + i;
    if (!mgmtCheckConfigShow(cfg)) continue;
    pShow->numOfRows++;
  }

  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  pShow->pNode = NULL;
  mgmtReleaseUser(pUser);

  return 0;
}

static int32_t mgmtRetrieveConfigs(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t numOfRows = 0;

  for (int32_t i = tsGlobalConfigNum - 1; i >= 0 && numOfRows < rows; --i) {
    SGlobalConfig *cfg = tsGlobalConfig + i;
    if (!mgmtCheckConfigShow(cfg)) continue;

    char *pWrite;
    int32_t   cols = 0;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    snprintf(pWrite, TSDB_CFG_OPTION_LEN, "%s", cfg->option);
    cols++;

    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    switch (cfg->valType) {
      case TSDB_CFG_VTYPE_SHORT:
        snprintf(pWrite, TSDB_CFG_VALUE_LEN, "%d", *((int16_t *)cfg->ptr));
        numOfRows++;
        break;
      case TSDB_CFG_VTYPE_INT:
        snprintf(pWrite, TSDB_CFG_VALUE_LEN, "%d", *((int32_t *)cfg->ptr));
        numOfRows++;
        break;
      case TSDB_CFG_VTYPE_UINT:
        snprintf(pWrite, TSDB_CFG_VALUE_LEN, "%d", *((uint32_t *)cfg->ptr));
        numOfRows++;
        break;
      case TSDB_CFG_VTYPE_FLOAT:
        snprintf(pWrite, TSDB_CFG_VALUE_LEN, "%f", *((float *)cfg->ptr));
        numOfRows++;
        break;
      case TSDB_CFG_VTYPE_STRING:
      case TSDB_CFG_VTYPE_IPSTR:
      case TSDB_CFG_VTYPE_DIRECTORY:
        snprintf(pWrite, TSDB_CFG_VALUE_LEN, "%s", (char *)cfg->ptr);
        numOfRows++;
        break;
      default:
        break;
    }
  }

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

static int32_t mgmtGetVnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
  int32_t cols = 0;
  SUserObj *pUser = mgmtGetUserFromConn(pConn, NULL);
  if (pUser == NULL) return 0;
  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_NO_RIGHTS;

  SSchema *pSchema = pMeta->schema;

  pShow->bytes[cols] = 4;
  pSchema[cols].type = TSDB_DATA_TYPE_INT;
  strcpy(pSchema[cols].name, "vnode");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 12;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "status");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pMeta->numOfColumns = htons(cols);
  pShow->numOfColumns = cols;

  pShow->offset[0] = 0;
  for (int32_t i = 1; i < cols; ++i) pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];

  SDnodeObj *pDnode = NULL;
  if (pShow->payloadLen > 0 ) {
    uint32_t ip = ip2uint(pShow->payload);
    pDnode = mgmtGetDnodeByIp(ip);
    if (NULL == pDnode) {
      return TSDB_CODE_NODE_OFFLINE;
    }

    SVnodeLoad* pVnode;
    pShow->numOfRows = 0;
    for (int32_t i = 0 ; i < TSDB_MAX_VNODES; i++) {
      pVnode = &pDnode->vload[i];
      if (0 != pVnode->vgId) {
        pShow->numOfRows++;
      }
    }
    
    pShow->pNode = pDnode;
  } else {
    while (true) {
      pShow->pNode = mgmtGetNextDnode(pShow->pNode, (SDnodeObj **)&pDnode);
      if (pDnode == NULL) break;
      pShow->numOfRows += pDnode->openVnodes;

      if (0 == pShow->numOfRows) return TSDB_CODE_NODE_OFFLINE;      
    }

    pShow->pNode = NULL;
  } 

  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
  mgmtReleaseDnode(pDnode);
  mgmtReleaseUser(pUser);

  return 0;
}

static int32_t mgmtRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
  int32_t    numOfRows = 0;
  SDnodeObj *pDnode = NULL;
  char *     pWrite;
  int32_t    cols = 0;

  if (0 == rows) return 0;

  if (pShow->payloadLen) {
    // output the vnodes info of the designated dnode. And output all vnodes of this dnode, instead of rows (max 100)
    pDnode = (SDnodeObj *)(pShow->pNode);
    if (pDnode != NULL) {
      SVnodeLoad* pVnode;
      for (int32_t i = 0 ; i < TSDB_MAX_VNODES; i++) {
        pVnode = &pDnode->vload[i];
        if (0 == pVnode->vgId) {
          continue;
        }
        
        cols = 0;
        
        pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
        *(uint32_t *)pWrite = pVnode->vgId;
        cols++;
        
        pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
        strcpy(pWrite, pVnode->status ? "ready" : "offline");
        cols++;
        
        numOfRows++;
      }
    }
  } else {
    // TODO: output all vnodes of all dnodes
    numOfRows = 0;
  }
  
  pShow->numOfReads += numOfRows;
  return numOfRows;
}

char* mgmtGetDnodeStatusStr(int32_t dnodeStatus) {
  switch (dnodeStatus) {
    case TAOS_DN_STATUS_OFFLINE:   return "offline";
    case TAOS_DN_STATUS_DROPPING:  return "dropping";
    case TAOS_DN_STATUS_BALANCING: return "balancing";
    case TAOS_DN_STATUS_READY:     return "ready";
    default:                       return "undefined";
  }
}