/*
 * 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 __USE_XOPEN

#include "shellAuto.h"
#include "shellInt.h"
#include "shellTire.h"
#include "tthread.h"

//
// ------------- define area  ---------------
//
#define UNION_ALL " union all "

// extern function
void  shellClearScreen(int32_t ecmd_pos, int32_t cursor_pos);
void  shellGetPrevCharSize(const char* str, int32_t pos, int32_t* size, int32_t* width);
void  shellShowOnScreen(SShellCmd* cmd);
void  shellInsertChar(SShellCmd* cmd, char* c, int size);
void  shellInsertStr(SShellCmd* cmd, char* str, int size);
bool  appendAfterSelect(TAOS* con, SShellCmd* cmd, char* p, int32_t len);
char* tireSearchWord(int type, char* pre);
bool  updateTireValue(int type, bool autoFill);

typedef struct SAutoPtr {
  STire* p;
  int    ref;
} SAutoPtr;

typedef struct SWord {
  int           type;  // word type , see WT_ define
  char*         word;
  int32_t       len;
  struct SWord* next;
  bool          free;  // if true need free
} SWord;

typedef struct {
  char*   source;
  int32_t source_len;  // valid data length in source
  int32_t count;
  SWord*  head;
  // matched information
  int32_t matchIndex;  // matched word index in words
  int32_t matchLen;    // matched length at matched word
} SWords;

SWords shellCommands[] = {
    {"alter database <db_name> <alter_db_options> <anyword> <alter_db_options> <anyword> <alter_db_options> <anyword> "
     "<alter_db_options> <anyword> <alter_db_options> <anyword> ;",
     0, 0, NULL},
    {"alter dnode <dnode_id> \"resetlog\";", 0, 0, NULL},
    {"alter dnode <dnode_id> \"debugFlag\" \"141\";", 0, 0, NULL},
    {"alter dnode <dnode_id> \"monitor\" \"0\";", 0, 0, NULL},
    {"alter dnode <dnode_id> \"monitor\" \"1\";", 0, 0, NULL},
    {"alter all dnodes \"resetlog\";", 0, 0, NULL},
    {"alter all dnodes \"debugFlag\" \"141\";", 0, 0, NULL},
    {"alter all dnodes \"monitor\" \"0\";", 0, 0, NULL},
    {"alter all dnodes \"monitor\" \"1\";", 0, 0, NULL},
    {"alter table <tb_name> <tb_actions> <anyword> ;", 0, 0, NULL},
    {"alter local \"resetlog\";", 0, 0, NULL},
    {"alter local \"DebugFlag\" \"143\";", 0, 0, NULL},
    {"alter local \"cDebugFlag\" \"143\";", 0, 0, NULL},
    {"alter local \"uDebugFlag\" \"143\";", 0, 0, NULL},
    {"alter local \"rpcDebugFlag\" \"143\";", 0, 0, NULL},
    {"alter local \"tmrDebugFlag\" \"143\";", 0, 0, NULL},
    {"alter topic", 0, 0, NULL},
    {"alter user <user_name> <user_actions> <anyword> ;", 0, 0, NULL},
    // 20
    {"create table <anyword> using <stb_name> tags(", 0, 0, NULL},
    {"create database <anyword> <db_options> <anyword> <db_options> <anyword> <db_options> <anyword> <db_options> "
     "<anyword> <db_options> <anyword> <db_options> <anyword> <db_options> <anyword> <db_options> <anyword> "
     "<db_options> <anyword> <db_options> <anyword> ;", 0, 0, NULL},
    {"create dnode <anyword>", 0, 0, NULL},
    {"create index <anyword> on <stb_name> ()", 0, 0, NULL},
    {"create mnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"create qnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"create stream <anyword> into <anyword> as select", 0, 0, NULL},  // 26 append sub sql
    {"create topic <anyword> as select", 0, 0, NULL},                  // 27 append sub sql
    {"create function <anyword> as <anyword> outputtype <data_types> language <udf_language>", 0, 0, NULL},
    {"create or replace <anyword> as <anyword> outputtype <data_types> language <udf_language>", 0, 0, NULL},
    {"create aggregate function  <anyword> as <anyword> outputtype <data_types> bufsize <anyword> language <udf_language>", 0, 0, NULL},
    {"create or replace aggregate function  <anyword> as <anyword> outputtype <data_types> bufsize <anyword> language <udf_language>", 0, 0, NULL},
    {"create user <anyword> pass <anyword> sysinfo 0;", 0, 0, NULL},
    {"create user <anyword> pass <anyword> sysinfo 1;", 0, 0, NULL},
#ifdef TD_ENTERPRISE
    {"compact database <db_name>", 0, 0, NULL},
#endif
    {"describe <all_table>", 0, 0, NULL},
    {"delete from <all_table> where ", 0, 0, NULL},
    {"drop database <db_name>", 0, 0, NULL},
    {"drop index <anyword>", 0, 0, NULL},
    {"drop table <all_table>", 0, 0, NULL},
    {"drop dnode <dnode_id>", 0, 0, NULL},
    {"drop mnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"drop qnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"drop user <user_name> ;", 0, 0, NULL},
    // 40
    {"drop function <udf_name> ;", 0, 0, NULL},
    {"drop consumer group <anyword> on ", 0, 0, NULL},
    {"drop topic <topic_name> ;", 0, 0, NULL},
    {"drop stream <stream_name> ;", 0, 0, NULL},
    {"explain select", 0, 0, NULL},  // 44 append sub sql
    {"flush database <db_name> ;", 0, 0, NULL},
    {"help;", 0, 0, NULL},
    {"grant all on <anyword> to <user_name> ;", 0, 0, NULL},
    {"grant read on <anyword> to <user_name> ;", 0, 0, NULL},
    {"grant write on <anyword> to <user_name> ;", 0, 0, NULL},
    {"kill connection <anyword> ;", 0, 0, NULL},
    {"kill query ", 0, 0, NULL},
    {"kill transaction ", 0, 0, NULL},
#ifdef TD_ENTERPRISE
    {"merge vgroup ", 0, 0, NULL},
#endif
    {"pause stream <stream_name> ;", 0, 0, NULL},
    {"resume stream <stream_name> ;", 0, 0, NULL},
    {"reset query cache;", 0, 0, NULL},
    {"restore dnode <dnode_id> ;", 0, 0, NULL},
    {"restore vnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"restore mnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"restore qnode on dnode <dnode_id> ;", 0, 0, NULL},
    {"revoke all on <anyword> from <user_name> ;", 0, 0, NULL},
    {"revoke read on <anyword> from <user_name> ;", 0, 0, NULL},
    {"revoke write on <anyword> from <user_name> ;", 0, 0, NULL},
    {"select * from <all_table>", 0, 0, NULL},
    {"select client_version();", 0, 0, NULL},
    // 60
    {"select current_user();", 0, 0, NULL},
    {"select database();", 0, 0, NULL},
    {"select server_version();", 0, 0, NULL},
    {"select server_status();", 0, 0, NULL},
    {"select now();", 0, 0, NULL},
    {"select today();", 0, 0, NULL},
    {"select timezone();", 0, 0, NULL},
    {"set max_binary_display_width ", 0, 0, NULL},
    {"show apps;", 0, 0, NULL},
    {"show create database <db_name> \\G;", 0, 0, NULL},
    {"show create stable <stb_name> \\G;", 0, 0, NULL},
    {"show create table <tb_name> \\G;", 0, 0, NULL},
    {"show connections;", 0, 0, NULL},
    {"show cluster;", 0, 0, NULL},
    {"show cluster alive;", 0, 0, NULL},
    {"show databases;", 0, 0, NULL},
    {"show dnodes;", 0, 0, NULL},
    {"show dnode <dnode_id> variables;", 0, 0, NULL},
    {"show functions;", 0, 0, NULL},
    {"show mnodes;", 0, 0, NULL},
    {"show queries;", 0, 0, NULL},
    // 80
    {"show query <anyword> ;", 0, 0, NULL},
    {"show qnodes;", 0, 0, NULL},
    {"show stables;", 0, 0, NULL},
    {"show stables like ", 0, 0, NULL},
    {"show streams;", 0, 0, NULL},
    {"show scores;", 0, 0, NULL},
    {"show snodes;", 0, 0, NULL},
    {"show subscriptions;", 0, 0, NULL},
    {"show tables;", 0, 0, NULL},
    {"show tables like", 0, 0, NULL},
    {"show table distributed <all_table>", 0, 0, NULL},
    {"show tags from <tb_name>", 0, 0, NULL},
    {"show tags from <db_name>", 0, 0, NULL},
    {"show topics;", 0, 0, NULL},
    {"show transactions;", 0, 0, NULL},
    {"show users;", 0, 0, NULL},
    {"show variables;", 0, 0, NULL},
    {"show local variables;", 0, 0, NULL},
    {"show vnodes <dnode_id>", 0, 0, NULL},
    {"show vgroups;", 0, 0, NULL},
    {"show consumers;", 0, 0, NULL},
    {"show grants;", 0, 0, NULL},
#ifdef TD_ENTERPRISE
    {"split vgroup ", 0, 0, NULL},
#endif    
    {"insert into <tb_name> values(", 0, 0, NULL},
    {"insert into <tb_name> using <stb_name> tags(", 0, 0, NULL},
    {"insert into <tb_name> using <stb_name> <anyword> values(", 0, 0, NULL},
    {"insert into <tb_name> file ", 0, 0, NULL},
    {"trim database <db_name>", 0, 0, NULL},
    {"use <db_name>", 0, 0, NULL},
    {"quit", 0, 0, NULL}};

char* keywords[] = {
    "and ",         "asc ",      "desc ",     "from ",    "fill(",         "limit ",    "where ",
    "interval(",    "order by ", "order by ", "offset ",  "or ",           "group by ", "now()",
    "session(",     "sliding ",  "slimit ",   "soffset ", "state_window(", "today() ",  "union all select ",
    "partition by "};

char* functions[] = {
    "count(",         "sum(",
    "avg(",           "last(",
    "last_row(",      "top(",
    "interp(",        "max(",
    "min(",           "now()",
    "today()",        "percentile(",
    "tail(",          "pow(",
    "abs(",           "atan(",
    "acos(",          "asin(",
    "apercentile(",   "bottom(",
    "cast(",          "ceil(",
    "char_length(",   "cos(",
    "concat(",        "concat_ws(",
    "csum(",          "diff(",
    "derivative(",    "elapsed(",
    "first(",         "floor(",
    "hyperloglog(",   "histogram(",
    "irate(",         "leastsquares(",
    "length(",        "log(",
    "lower(",         "ltrim(",
    "mavg(",          "mode(",
    "tan(",           "round(",
    "rtrim(",         "sample(",
    "sin(",           "spread(",
    "substr(",        "statecount(",
    "stateduration(", "stddev(",
    "sqrt(",          "timediff(",
    "timezone(",      "timetruncate(",
    "twa(",           "to_unixtimestamp(",
    "unique(",        "upper(",
};

char* tb_actions[] = {
    "add column ", "modify column ", "drop column ", "rename column ", "add tag ",
    "modify tag ", "drop tag ",      "rename tag ",  "set tag ",
};

char* user_actions[] = {"pass ", "enable ", "sysinfo "};

char* tb_options[] = {"comment ", "watermark ", "max_delay ", "ttl ", "rollup(", "sma("};

char* db_options[] = {"keep ",
                      "replica ",
                      "precision ",
                      "strict ",
                      "buffer ",
                      "cachemodel ",
                      "cachesize ",
                      "comp ",
                      "duration ",
                      "wal_fsync_period",
                      "maxrows ",
                      "minrows ",
                      "pages ",
                      "pagesize ",
                      "retentions ",
                      "wal_level ",
                      "vgroups ",
                      "single_stable ",
                      "wal_retention_period ",
                      "wal_roll_period ",
                      "wal_retention_size ",
                      "wal_segment_size "};

char* alter_db_options[] = {"cachemodel ", "replica ", "keep ", "cachesize ", "wal_fsync_period ", "wal_level "};

char* data_types[] = {"timestamp",    "int",
                      "int unsigned", "varchar(16)",
                      "float",        "double",
                      "binary(16)",   "nchar(16)",
                      "bigint",       "bigint unsigned",
                      "smallint",     "smallint unsigned",
                      "tinyint",      "tinyint unsigned",
                      "bool",         "json"};

char* key_tags[] = {"tags("};

char* key_select[] = {"select "};

char* key_systable[] = {
    "ins_dnodes",        "ins_mnodes",     "ins_modules",      "ins_qnodes",  "ins_snodes",          "ins_cluster",
    "ins_databases",     "ins_functions",  "ins_indexes",      "ins_stables", "ins_tables",          "ins_tags",
    "ins_users",         "ins_grants",     "ins_vgroups",      "ins_configs", "ins_dnode_variables", "ins_topics",
    "ins_subscriptions", "ins_streams",    "ins_stream_tasks", "ins_vnodes",  "ins_user_privileges", "perf_connections",
    "perf_queries",      "perf_consumers", "perf_trans",       "perf_apps"};

char* udf_language[] = {"\'Python\'", "\'C\'"};

//
//  ------- global variant define ---------
//
int32_t firstMatchIndex = -1;  // first match shellCommands index
int32_t lastMatchIndex = -1;   // last match shellCommands index
int32_t curMatchIndex = -1;    // current match shellCommands index
int32_t lastWordBytes = -1;    // printShow last word length
bool    waitAutoFill = false;

//
//   ----------- global var array define -----------
//
#define WT_VAR_DBNAME         0
#define WT_VAR_STABLE         1
#define WT_VAR_TABLE          2
#define WT_VAR_DNODEID        3
#define WT_VAR_USERNAME       4
#define WT_VAR_TOPIC          5
#define WT_VAR_STREAM         6
#define WT_VAR_UDFNAME        7

#define WT_FROM_DB_MAX        7  // max get content from db
#define WT_FROM_DB_CNT (WT_FROM_DB_MAX + 1)

#define WT_VAR_ALLTABLE       8
#define WT_VAR_FUNC           9
#define WT_VAR_KEYWORD        10
#define WT_VAR_TBACTION       11
#define WT_VAR_DBOPTION       12
#define WT_VAR_ALTER_DBOPTION 13
#define WT_VAR_DATATYPE       14
#define WT_VAR_KEYTAGS        15
#define WT_VAR_ANYWORD        16
#define WT_VAR_TBOPTION       17
#define WT_VAR_USERACTION     18
#define WT_VAR_KEYSELECT      19
#define WT_VAR_SYSTABLE       20
#define WT_VAR_LANGUAGE       21

#define WT_VAR_CNT 22


#define WT_TEXT 0xFF

char dbName[256] = "";  // save use database name;
// tire array
STire*        tires[WT_VAR_CNT];
TdThreadMutex tiresMutex;
// save thread handle obtain var name from db server
TdThread* threads[WT_FROM_DB_CNT];
// obtain var name  with sql from server
char varTypes[WT_VAR_CNT][64] = {
    "<db_name>",    "<stb_name>",  "<tb_name>",  "<dnode_id>",  "<user_name>",    "<topic_name>", "<stream_name>",
    "<udf_name>",   "<all_table>", "<function>", "<keyword>",    "<tb_actions>",   "<db_options>", "<alter_db_options>",
    "<data_types>", "<key_tags>",  "<anyword>",  "<tb_options>", "<user_actions>", "<key_select>", "<sys_table>", "<udf_language>"};

char varSqls[WT_FROM_DB_CNT][64] = {"show databases;", "show stables;", "show tables;", "show dnodes;",
                                    "show users;",     "show topics;",  "show streams;", "show functions;"};

// var words current cursor, if user press any one key except tab, cursorVar can be reset to -1
int  cursorVar = -1;
bool varMode = false;  // enter var names list mode

TAOS*      varCon = NULL;
SShellCmd* varCmd = NULL;
bool       varRunOnce = false;
SMatch*    lastMatch = NULL;  // save last match result
int        cntDel = 0;        // delete byte count after next press tab

// show auto tab introduction
void printfIntroduction() {
  printf("  ********************************  Tab Completion  ************************************\n");
  char secondLine[160] = "\0";
  sprintf(secondLine, "  *   The %s CLI supports tab completion for a variety of items, ", shell.info.cusName);
  printf("%s", secondLine);
  int secondLineLen = strlen(secondLine);
  while (87 - (secondLineLen++) > 0) {
    printf(" ");
  }
  printf("*\n");
  printf("  *   including database names, table names, function names and keywords.              *\n");
  printf("  *   The full list of shortcut keys is as follows:                                    *\n");
  printf("  *    [ TAB ]        ......  complete the current word                                *\n");
  printf("  *                   ......  if used on a blank line, display all supported commands  *\n");
  printf("  *    [ Ctrl + A ]   ......  move cursor to the st[A]rt of the line                   *\n");
  printf("  *    [ Ctrl + E ]   ......  move cursor to the [E]nd of the line                     *\n");
  printf("  *    [ Ctrl + W ]   ......  move cursor to the middle of the line                    *\n");
  printf("  *    [ Ctrl + L ]   ......  clear the entire screen                                  *\n");
  printf("  *    [ Ctrl + K ]   ......  clear the screen after the cursor                        *\n");
  printf("  *    [ Ctrl + U ]   ......  clear the screen before the cursor                       *\n");
  printf("  **************************************************************************************\n\n");
}

void showHelp() {
  printf("\nThe %s CLI supports the following commands:", shell.info.cusName);
  printf(
      "\n\
  ----- A ----- \n\
    alter database <db_name> <db_options> \n\
    alter dnode <dnode_id> 'resetlog';\n\
    alter dnode <dnode_id> 'monitor' '0';\n\
    alter dnode <dnode_id> 'monitor' \"1\";\n\
    alter dnode <dnode_id> \"debugflag\" \"143\";\n\
    alter all dnodes \"monitor\" \"0\";\n\
    alter all dnodes \"monitor\" \"1\";\n\
    alter all dnodes \"resetlog\";\n\
    alter all dnodes \"debugFlag\" \n\
    alter table <tb_name> <tb_actions> ;\n\
    alter local \"resetlog\";\n\
    alter local \"DebugFlag\" \"143\";\n\
    alter topic\n\
    alter user <user_name> <user_actions> ...\n\
  ----- C ----- \n\
    create table <tb_name> using <stb_name> tags ...\n\
    create database <db_name> <db_options>  ...\n\
    create dnode \"fqdn:port\" ...\n\
    create index <index_name> on <stb_name> (tag_column_name);\n\
    create mnode on dnode <dnode_id> ;\n\
    create qnode on dnode <dnode_id> ;\n\
    create stream <stream_name> into <stb_name> as select ...\n\
    create topic <topic_name> as select ...\n\
    create function <udf_name> as <file_name> outputtype <data_types> language \'C\' | \'Python\' ;\n\
    create aggregate function  <udf_name> as <file_name> outputtype <data_types> bufsize <bufsize_bytes> language \'C\' | \'Python\';\n\
    create user <user_name> pass <password> ...\n\
  ----- D ----- \n\
    describe <all_table>\n\
    delete from <all_table> where ...\n\
    drop database <db_name>;\n\
    drop table <all_table>;\n\
    drop dnode <dnode_id>;\n\
    drop mnode on dnode <dnode_id> ;\n\
    drop qnode on dnode <dnode_id> ;\n\
    drop user <user_name> ;\n\
    drop function <udf_name>;\n\
    drop consumer group ... \n\
    drop topic <topic_name> ;\n\
    drop stream <stream_name> ;\n\
    drop index <index_name>;\n\
  ----- E ----- \n\
    explain select clause ...\n\
  ----- F ----- \n\
    flush database <db_name>;\n\
  ----- H ----- \n\
    help;\n\
  ----- I ----- \n\
    insert into <tb_name> values(...) ;\n\
    insert into <tb_name> using <stb_name> tags(...) values(...) ;\n\
  ----- G ----- \n\
    grant all   on <priv_level> to <user_name> ;\n\
    grant read  on <priv_level> to <user_name> ;\n\
    grant write on <priv_level> to <user_name> ;\n\
  ----- K ----- \n\
    kill connection <connection_id>; \n\
    kill query <query_id>; \n\
    kill transaction <transaction_id>;\n\
  ----- P ----- \n\
    pause stream <stream_name>;\n\
  ----- R ----- \n\
    resume stream <stream_name>;\n\
    reset query cache;\n\
    restore dnode <dnode_id> ;\n\
    restore vnode on dnode <dnode_id> ;\n\
    restore mnode on dnode <dnode_id> ;\n\
    restore qnode on dnode <dnode_id> ;\n\
    revoke all   on <priv_level> from <user_name> ;\n\
    revoke read  on <priv_level> from <user_name> ;\n\
    revoke write on <priv_level> from <user_name> ;\n\
  ----- S ----- \n\
    select * from <all_table> where ... \n\
    select client_version();\n\
    select current_user();\n\
    select database();\n\
    select server_version();\n\
    select server_status();\n\
    select now();\n\
    select today();\n\
    select timezone();\n\
    set max_binary_display_width ...\n\
    show apps;\n\
    show create database <db_name>;\n\
    show create stable <stb_name>;\n\
    show create table <tb_name>;\n\
    show connections;\n\
    show cluster;\n\
    show cluster alive;\n\
    show databases;\n\
    show dnodes;\n\
    show dnode <dnode_id> variables;\n\
    show functions;\n\
    show mnodes;\n\
    show queries;\n\
    show query <query_id> ;\n\
    show qnodes;\n\
    show snodes;\n\
    show stables;\n\
    show stables like \n\
    show streams;\n\
    show scores;\n\
    show subscriptions;\n\
    show tables;\n\
    show tables like\n\
    show table distributed <all_table>;\n\
    show tags from <tb_name>\n\
    show tags from <db_name>\n\
    show topics;\n\
    show transactions;\n\
    show users;\n\
    show variables;\n\
    show local variables;\n\
    show vnodes <dnode_id>\n\
    show vgroups;\n\
    show consumers;\n\
    show grants;\n\
  ----- T ----- \n\
    trim database <db_name>;\n\
  ----- U ----- \n\
    use <db_name>;");

#ifdef TD_ENTERPRISE
  printf(
      "\n\n\
  ----- special commands on enterpise version ----- \n\
    compact database <db_name>; \n\
    split vgroup <vgroup_id>;");
#endif

  printf("\n\n");
  // define in getDuration() function
  printf(
      "\
  Timestamp expression Format:\n\
    b - nanosecond \n\
    u - microsecond \n\
    a - millisecond \n\
    s - second \n\
    m - minute \n\
    h - hour \n\
    d - day \n\
    w - week \n\
    now - current time \n\
  Example : \n\
    select * from t1 where ts > now - 2w + 3d and ts <= now - 1w -2h ;\n");
  printf("\n");
}

//
//  -------------------  parse words --------------------------
//

#define SHELL_COMMAND_COUNT() (sizeof(shellCommands) / sizeof(SWords))

// get at
SWord* atWord(SWords* command, int32_t index) {
  SWord* word = command->head;
  for (int32_t i = 0; i < index; i++) {
    if (word == NULL) return NULL;
    word = word->next;
  }

  return word;
}

#define MATCH_WORD(x) atWord(x, x->matchIndex)

int wordType(const char* p, int32_t len) {
  for (int i = 0; i < WT_VAR_CNT; i++) {
    if (strncmp(p, varTypes[i], len) == 0) return i;
  }
  return WT_TEXT;
}

// add word
SWord* addWord(const char* p, int32_t len, bool pattern) {
  SWord* word = (SWord*)taosMemoryMalloc(sizeof(SWord));
  memset(word, 0, sizeof(SWord));
  word->word = (char*)p;
  word->len = len;

  // check format
  if (pattern && len > 0) {
    word->type = wordType(p, len);
  } else {
    word->type = WT_TEXT;
  }

  return word;
}

// parse one command
void parseCommand(SWords* command, bool pattern) {
  char*   p = command->source;
  int32_t start = 0;
  int32_t size = command->source_len > 0 ? command->source_len : strlen(p);

  bool lastBlank = false;
  for (int i = 0; i <= size; i++) {
    if (p[i] == ' ' || i == size) {
      // check continue blank like '    '
      if (p[i] == ' ') {
        if (lastBlank) {
          start++;
          continue;
        }
        if (i == 0) {  // first blank
          lastBlank = true;
          start++;
          continue;
        }
        lastBlank = true;
      }

      // found split or string end , append word
      if (command->head == NULL) {
        command->head = addWord(p + start, i - start, pattern);
        command->count = 1;
      } else {
        SWord* word = command->head;
        while (word->next) {
          word = word->next;
        }
        word->next = addWord(p + start, i - start, pattern);
        command->count++;
      }
      start = i + 1;
    } else {
      lastBlank = false;
    }
  }
}

// free SShellCmd
void freeCommand(SWords* command) {
  SWord* item = command->head;
  command->head = NULL;
  // loop
  while (item) {
    SWord* tmp = item;
    item = item->next;
    // if malloc need free
    if (tmp->free && tmp->word) taosMemoryFree(tmp->word);
    taosMemoryFree(tmp);
  }
}

void GenerateVarType(int type, char** p, int count) {
  STire* tire = createTire(TIRE_LIST);
  for (int i = 0; i < count; i++) {
    insertWord(tire, p[i]);
  }

  taosThreadMutexLock(&tiresMutex);
  tires[type] = tire;
  taosThreadMutexUnlock(&tiresMutex);
}

//
//  -------------------- shell auto ----------------
//

// init shell auto function , shell start call once
bool shellAutoInit() {
  // command
  int32_t count = SHELL_COMMAND_COUNT();
  for (int32_t i = 0; i < count; i++) {
    parseCommand(shellCommands + i, true);
  }

  // tires
  memset(tires, 0, sizeof(STire*) * WT_VAR_CNT);
  taosThreadMutexInit(&tiresMutex, NULL);

  // threads
  memset(threads, 0, sizeof(TdThread*) * WT_FROM_DB_CNT);

  // generate varType
  GenerateVarType(WT_VAR_FUNC, functions, sizeof(functions) / sizeof(char*));
  GenerateVarType(WT_VAR_KEYWORD, keywords, sizeof(keywords) / sizeof(char*));
  GenerateVarType(WT_VAR_DBOPTION, db_options, sizeof(db_options) / sizeof(char*));
  GenerateVarType(WT_VAR_ALTER_DBOPTION, alter_db_options, sizeof(alter_db_options) / sizeof(char*));
  GenerateVarType(WT_VAR_TBACTION, tb_actions, sizeof(tb_actions) / sizeof(char*));
  GenerateVarType(WT_VAR_DATATYPE, data_types, sizeof(data_types) / sizeof(char*));
  GenerateVarType(WT_VAR_KEYTAGS, key_tags, sizeof(key_tags) / sizeof(char*));
  GenerateVarType(WT_VAR_TBOPTION, tb_options, sizeof(tb_options) / sizeof(char*));
  GenerateVarType(WT_VAR_USERACTION, user_actions, sizeof(user_actions) / sizeof(char*));
  GenerateVarType(WT_VAR_KEYSELECT, key_select, sizeof(key_select) / sizeof(char*));
  GenerateVarType(WT_VAR_SYSTABLE, key_systable, sizeof(key_systable) / sizeof(char*));
  GenerateVarType(WT_VAR_LANGUAGE, udf_language, sizeof(udf_language) / sizeof(char*));

  return true;
}

// set conn
void shellSetConn(TAOS* conn, bool runOnce) {
  varCon = conn;
  varRunOnce = runOnce;
  // init database and stable
  if (!runOnce) updateTireValue(WT_VAR_DBNAME, false);
}

// exit shell auto function, shell exit call once
void shellAutoExit() {
  // free command
  int32_t count = SHELL_COMMAND_COUNT();
  for (int32_t i = 0; i < count; i++) {
    freeCommand(shellCommands + i);
  }

  // free tires
  taosThreadMutexLock(&tiresMutex);
  for (int32_t i = 0; i < WT_VAR_CNT; i++) {
    if (tires[i]) {
      freeTire(tires[i]);
      tires[i] = NULL;
    }
  }
  taosThreadMutexUnlock(&tiresMutex);
  // destroy
  taosThreadMutexDestroy(&tiresMutex);

  // free threads
  for (int32_t i = 0; i < WT_FROM_DB_CNT; i++) {
    if (threads[i]) {
      taosDestroyThread(threads[i]);
      threads[i] = NULL;
    }
  }

  // free lastMatch
  if (lastMatch) {
    freeMatch(lastMatch);
    lastMatch = NULL;
  }
}

//
//  -------------------  auto ptr for tires --------------------------
//
bool setNewAutoPtr(int type, STire* pNew) {
  if (pNew == NULL) return false;

  taosThreadMutexLock(&tiresMutex);
  STire* pOld = tires[type];
  if (pOld != NULL) {
    // previous have value, release self ref count
    if (--pOld->ref == 0) {
      freeTire(pOld);
    }
  }

  // set new
  tires[type] = pNew;
  tires[type]->ref = 1;
  taosThreadMutexUnlock(&tiresMutex);

  return true;
}

// get ptr
STire* getAutoPtr(int type) {
  if (tires[type] == NULL) {
    return NULL;
  }

  taosThreadMutexLock(&tiresMutex);
  tires[type]->ref++;
  taosThreadMutexUnlock(&tiresMutex);

  return tires[type];
}

// put back tire to tires[type], if tire not equal tires[type].p, need free tire
void putBackAutoPtr(int type, STire* tire) {
  if (tire == NULL) {
    return;
  }

  taosThreadMutexLock(&tiresMutex);
  if (tires[type] != tire) {
    // update by out,  can't put back , so free
    if (--tire->ref == 1) {
      // support multi thread getAutoPtr
      freeTire(tire);
    }

  } else {
    tires[type]->ref--;
    ASSERT(tires[type]->ref > 0);
  }
  taosThreadMutexUnlock(&tiresMutex);

  return;
}

//
//  -------------------  var Word --------------------------
//

#define MAX_CACHED_CNT 100000  // max cached rows 10w
// write sql result to var name, return write rows cnt
int writeVarNames(int type, TAOS_RES* tres) {
  // fetch row
  TAOS_ROW row = taos_fetch_row(tres);
  if (row == NULL) {
    return 0;
  }

  TAOS_FIELD* fields = taos_fetch_fields(tres);
  // create new tires
  char   tireType = type == WT_VAR_TABLE ? TIRE_TREE : TIRE_LIST;
  STire* tire = createTire(tireType);

  // enum rows
  char name[1024];
  int  numOfRows = 0;
  do {
    int32_t* lengths = taos_fetch_lengths(tres);
    int32_t  bytes = lengths[0];
    if (fields[0].type == TSDB_DATA_TYPE_INT) {
      sprintf(name, "%d", *(int16_t*)row[0]);
    } else {
      memcpy(name, row[0], bytes);
    }

    name[bytes] = 0;  // set string end
    // insert to tire
    insertWord(tire, name);

    if (++numOfRows > MAX_CACHED_CNT) {
      break;
    }

    row = taos_fetch_row(tres);
  } while (row != NULL);

  // replace old tire
  setNewAutoPtr(type, tire);

  return numOfRows;
}

void setThreadNull(int type) {
  taosThreadMutexLock(&tiresMutex);
  if (threads[type]) {
    taosMemoryFree(threads[type]);
  }
  threads[type] = NULL;
  taosThreadMutexUnlock(&tiresMutex);
}

bool firstMatchCommand(TAOS* con, SShellCmd* cmd);
//
//  thread obtain var thread from db server
//
void* varObtainThread(void* param) {
  int type = *(int*)param;
  taosMemoryFree(param);

  if (varCon == NULL || type > WT_FROM_DB_MAX) {
    return NULL;
  }

  TAOS_RES* pSql = taos_query(varCon, varSqls[type]);
  if (taos_errno(pSql)) {
    taos_free_result(pSql);
    setThreadNull(type);
    return NULL;
  }

  // write var names from pSql
  int cnt = writeVarNames(type, pSql);

  // free sql
  taos_free_result(pSql);

  // check need call auto tab
  if (cnt > 0 && waitAutoFill) {
    // press tab key by program
    firstMatchCommand(varCon, varCmd);
  }

  setThreadNull(type);
  return NULL;
}

// return true is need update value by async
bool updateTireValue(int type, bool autoFill) {
  // TYPE CONTEXT GET FROM DB
  taosThreadMutexLock(&tiresMutex);

  // check need obtain from server
  if (tires[type] == NULL) {
    waitAutoFill = autoFill;
    // need async obtain var names from db sever
    if (threads[type] != NULL) {
      if (taosThreadRunning(threads[type])) {
        // thread running , need not obtain again, return
        taosThreadMutexUnlock(&tiresMutex);
        return NULL;
      }
      // destroy previous thread handle for new create thread handle
      taosDestroyThread(threads[type]);
      threads[type] = NULL;
    }

    // create new
    void* param = taosMemoryMalloc(sizeof(int));
    *((int*)param) = type;
    threads[type] = taosCreateThread(varObtainThread, param);
    taosThreadMutexUnlock(&tiresMutex);
    return true;
  }
  taosThreadMutexUnlock(&tiresMutex);

  return false;
}

// only match next one word from all match words, return valuue must free by caller
char* matchNextPrefix(STire* tire, char* pre) {
  SMatch* match = NULL;
  if (tire == NULL) return NULL;

  // re-use last result
  if (lastMatch) {
    if (strcmp(pre, lastMatch->pre) == 0) {
      // same pre
      match = lastMatch;
    }
  }

  if (match == NULL) {
    // not same with last result
    if (pre[0] == 0) {
      // EMPTY PRE
      match = enumAll(tire);
    } else {
      // NOT EMPTY
      match = (SMatch*)taosMemoryMalloc(sizeof(SMatch));
      memset(match, 0, sizeof(SMatch));
      matchPrefix(tire, pre, match);
    }

    // save to lastMatch
    if (match) {
      if (lastMatch) freeMatch(lastMatch);
      lastMatch = match;
    }
  }

  // check valid
  if (match == NULL || match->head == NULL) {
    // no one matched
    return NULL;
  }

  if (cursorVar == -1) {
    // first
    cursorVar = 0;
    return taosStrdup(match->head->word);
  }

  // according to cursorVar , calculate next one
  int         i = 0;
  SMatchNode* item = match->head;
  while (item) {
    if (i == cursorVar + 1) {
      // found next position ok
      if (item->next == NULL) {
        // match last item, reset cursorVar to head
        cursorVar = -1;
      } else {
        cursorVar = i;
      }

      return taosStrdup(item->word);
    }

    // check end item
    if (item->next == NULL) {
      // if cursorVar > var list count, return last and reset cursorVar
      cursorVar = -1;

      return taosStrdup(item->word);
    }

    // move next
    item = item->next;
    i++;
  }

  return NULL;
}

// search pre word from tire tree, return value must free by caller
char* tireSearchWord(int type, char* pre) {
  if (type == WT_TEXT) {
    return NULL;
  }

  if (type > WT_FROM_DB_MAX) {
    // NOT FROM DB , tires[type] alwary not null
    STire* tire = tires[type];
    if (tire == NULL) return NULL;
    return matchNextPrefix(tire, pre);
  }

  if (updateTireValue(type, true)) {
    return NULL;
  }

  // can obtain var names from local
  STire* tire = getAutoPtr(type);
  if (tire == NULL) {
    return NULL;
  }

  char* str = matchNextPrefix(tire, pre);
  // used finish, put back pointer to autoptr array
  putBackAutoPtr(type, tire);

  return str;
}

// match var word, word1 is pattern , word2 is input from shell
bool matchVarWord(SWord* word1, SWord* word2) {
  // search input word from tire tree
  char pre[512];
  memcpy(pre, word2->word, word2->len);
  pre[word2->len] = 0;

  char* str = NULL;
  if (word1->type == WT_VAR_ALLTABLE) {
    // ALL_TABLE
    str = tireSearchWord(WT_VAR_STABLE, pre);
    if (str == NULL) {
      str = tireSearchWord(WT_VAR_TABLE, pre);
      if (str == NULL) return false;
    }
  } else {
    // OTHER
    str = tireSearchWord(word1->type, pre);
    if (str == NULL) {
      // not found or word1->type variable list not obtain from server, return not match
      return false;
    }
  }

  // free previous malloc
  if (word1->free && word1->word) {
    taosMemoryFree(word1->word);
  }

  // save
  word1->word = str;
  word1->len = strlen(str);
  word1->free = true;  // need free

  return true;
}

//
//  -------------------  match words --------------------------
//

// compare command cmdPattern come from shellCommands , cmdInput come from user input
int32_t compareCommand(SWords* cmdPattern, SWords* cmdInput) {
  SWord* wordPattern = cmdPattern->head;
  SWord* wordInput = cmdInput->head;

  if (wordPattern == NULL || wordInput == NULL) {
    return -1;
  }

  for (int32_t i = 0; i < cmdPattern->count; i++) {
    if (wordPattern->type == WT_TEXT) {
      // WT_TEXT match
      if (wordPattern->len == wordInput->len) {
        if (strncasecmp(wordPattern->word, wordInput->word, wordPattern->len) != 0) return -1;
      } else if (wordPattern->len < wordInput->len) {
        return -1;
      } else {
        // wordPattern->len > wordInput->len
        if (strncasecmp(wordPattern->word, wordInput->word, wordInput->len) == 0) {
          if (i + 1 == cmdInput->count) {
            // last word return match
            cmdPattern->matchIndex = i;
            cmdPattern->matchLen = wordInput->len;
            return i;
          } else {
            return -1;
          }
        } else {
          return -1;
        }
      }
    } else {
      // WT_VAR auto match any one word
      if (wordInput->next == NULL) {  // input words last one
        if (matchVarWord(wordPattern, wordInput)) {
          cmdPattern->matchIndex = i;
          cmdPattern->matchLen = wordInput->len;
          varMode = true;
          return i;
        }
        return -1;
      }
    }

    // move next
    wordPattern = wordPattern->next;
    wordInput = wordInput->next;
    if (wordPattern == NULL || wordInput == NULL) {
      return -1;
    }
  }

  return -1;
}

// match command
SWords* matchCommand(SWords* input, bool continueSearch) {
  int32_t count = SHELL_COMMAND_COUNT();
  for (int32_t i = 0; i < count; i++) {
    SWords* shellCommand = shellCommands + i;
    if (continueSearch && lastMatchIndex != -1 && i <= lastMatchIndex) {
      // new match must greater than lastMatchIndex
      if (varMode && i == lastMatchIndex) {
        // do nothing, var match on lastMatchIndex
      } else {
        continue;
      }
    }

    // command is large
    if (input->count > shellCommand->count) {
      continue;
    }

    // compare
    int32_t index = compareCommand(shellCommand, input);
    if (index != -1) {
      if (firstMatchIndex == -1) firstMatchIndex = i;
      curMatchIndex = i;
      return &shellCommands[i];
    }
  }

  // not match
  return NULL;
}

//
//  -------------------  print screen --------------------------
//

// delete char count
void deleteCount(SShellCmd* cmd, int count) {
  int size = 0;
  int width = 0;
  int prompt_size = 6;
  shellClearScreen(cmd->endOffset + prompt_size, cmd->screenOffset + prompt_size);

  // loop delete
  while (--count >= 0 && cmd->cursorOffset > 0) {
    shellGetPrevCharSize(cmd->command, cmd->cursorOffset, &size, &width);
    memmove(cmd->command + cmd->cursorOffset - size, cmd->command + cmd->cursorOffset,
            cmd->commandSize - cmd->cursorOffset);
    cmd->commandSize -= size;
    cmd->cursorOffset -= size;
    cmd->screenOffset -= width;
    cmd->endOffset -= width;
  }
}

// show screen
void printScreen(TAOS* con, SShellCmd* cmd, SWords* match) {
  // modify SShellCmd
  if (firstMatchIndex == -1 || curMatchIndex == -1) {
    // no match
    return;
  }

  // first tab press
  const char* str = NULL;
  int         strLen = 0;

  if (firstMatchIndex == curMatchIndex && lastWordBytes == -1) {
    // first press tab
    SWord* word = MATCH_WORD(match);
    str = word->word + match->matchLen;
    strLen = word->len - match->matchLen;
    lastMatchIndex = firstMatchIndex;
    lastWordBytes = word->len;
  } else {
    if (lastWordBytes == -1) return;
    deleteCount(cmd, lastWordBytes);

    SWord* word = MATCH_WORD(match);
    str = word->word;
    strLen = word->len;
    // set current to last
    lastMatchIndex = curMatchIndex;
    lastWordBytes = word->len;
  }

  // insert new
  shellInsertStr(cmd, (char*)str, strLen);
}

// main key press tab , matched return true else false
bool firstMatchCommand(TAOS* con, SShellCmd* cmd) {
  if (con == NULL || cmd == NULL) return false;
  // parse command
  SWords* input = (SWords*)taosMemoryMalloc(sizeof(SWords));
  memset(input, 0, sizeof(SWords));
  input->source = cmd->command;
  input->source_len = cmd->commandSize;
  parseCommand(input, false);

  // if have many , default match first, if press tab again , switch to next
  curMatchIndex = -1;
  lastMatchIndex = -1;
  SWords* match = matchCommand(input, true);
  if (match == NULL) {
    // not match , nothing to do
    freeCommand(input);
    taosMemoryFree(input);
    return false;
  }

  // print to screen
  printScreen(con, cmd, match);
#ifdef WINDOWS
  printf("\r");
  shellShowOnScreen(cmd);
#endif
  freeCommand(input);
  taosMemoryFree(input);
  return true;
}

// create input source
void createInputFromFirst(SWords* input, SWords* firstMatch) {
  //
  // if next pressTabKey , input context come from firstMatch, set matched length with source_len
  //
  input->source = (char*)taosMemoryMalloc(1024);
  memset((void*)input->source, 0, 1024);

  SWord* word = firstMatch->head;

  // source_len = full match word->len + half match with firstMatch->matchLen
  for (int i = 0; i < firstMatch->matchIndex && word; i++) {
    // combine source from each word
    strncpy(input->source + input->source_len, word->word, word->len);
    strcat(input->source, " ");          // append blank space
    input->source_len += word->len + 1;  // 1 is blank length
    // move next
    word = word->next;
  }
  // appand half matched word for last
  if (word) {
    strncpy(input->source + input->source_len, word->word, firstMatch->matchLen);
    input->source_len += firstMatch->matchLen;
  }
}

// user press Tabkey again is named next , matched return true else false
bool nextMatchCommand(TAOS* con, SShellCmd* cmd, SWords* firstMatch) {
  if (firstMatch == NULL || firstMatch->head == NULL) {
    return false;
  }
  SWords* input = (SWords*)taosMemoryMalloc(sizeof(SWords));
  memset(input, 0, sizeof(SWords));

  // create input from firstMatch
  createInputFromFirst(input, firstMatch);

  // parse input
  parseCommand(input, false);

  // if have many , default match first, if press tab again , switch to next
  SWords* match = matchCommand(input, true);
  if (match == NULL) {
    // if not match , reset all index
    firstMatchIndex = -1;
    curMatchIndex = -1;
    match = matchCommand(input, false);
    if (match == NULL) {
      freeCommand(input);
      if (input->source) taosMemoryFree(input->source);
      taosMemoryFree(input);
      return false;
    }
  }

  // print to screen
  printScreen(con, cmd, match);
#ifdef WINDOWS
  printf("\r");
  shellShowOnScreen(cmd);
#endif

  // free
  freeCommand(input);
  if (input->source) {
    taosMemoryFree(input->source);
    input->source = NULL;
  }
  taosMemoryFree(input);

  return true;
}

// fill with type
bool fillWithType(TAOS* con, SShellCmd* cmd, char* pre, int type) {
  // get type
  STire* tire = tires[type];
  char*  str = matchNextPrefix(tire, pre);
  if (str == NULL) {
    return false;
  }

  // need insert part string
  char* part = str + strlen(pre);

  // show
  int count = strlen(part);
  shellInsertStr(cmd, part, count);
  cntDel = count;  // next press tab delete current append count

  taosMemoryFree(str);
  return true;
}

// fill with type
bool fillTableName(TAOS* con, SShellCmd* cmd, char* pre) {
  // search stable and table
  char* str = tireSearchWord(WT_VAR_STABLE, pre);
  if (str == NULL) {
    str = tireSearchWord(WT_VAR_TABLE, pre);
    if (str == NULL) return false;
  }

  // need insert part string
  char* part = str + strlen(pre);

  // delete autofill count last append
  if (cntDel > 0) {
    deleteCount(cmd, cntDel);
    cntDel = 0;
  }

  // show
  int count = strlen(part);
  shellInsertStr(cmd, part, count);
  cntDel = count;  // next press tab delete current append count

  taosMemoryFree(str);
  return true;
}

//
// find last word from sql select clause
//  example :
//  1 select cou -> press tab  select count(
//  2 select count(*),su -> select count(*), sum(
//  3 select count(*), su -> select count(*), sum(
//
char* lastWord(char* p) {
  // get near from end revert find ' ' and ','
  char* p1 = strrchr(p, ' ');
  char* p2 = strrchr(p, ',');

  if (p1 && p2) {
    return p1 > p2 ? p1 + 1 : p2 + 1;
  } else if (p1) {
    return p1 + 1;
  } else if (p2) {
    return p2 + 1;
  } else {
    return p;
  }
}

bool fieldsInputEnd(char* sql) {
  // not in '()'
  char* p1 = strrchr(sql, '(');
  char* p2 = strrchr(sql, ')');
  if (p1 && p2 == NULL) {
    // like select count( '  '
    return false;
  } else if (p1 && p2 && p1 > p2) {
    // like select sum(age), count( ' '
    return false;
  }

  // not in ','
  char* p3 = strrchr(sql, ',');
  char* p = p3;
  // like select ts, age,'    '
  if (p) {
    ++p;
    bool  allBlank = true;  // after last ','  all char is blank
    int   cnt = 0;          // blank count , like '    ' as one blank
    char* plast = NULL;     // last blank position
    while (*p) {
      if (*p == ' ') {
        plast = p;
        cnt++;
      } else {
        allBlank = false;
      }
      ++p;
    }

    // any one word is not blank
    if (allBlank) {
      return false;
    }

    // like 'select count(*),sum(age) fr' need return true
    if (plast && plast > p3 && p2 > p1 && plast > p2 && p1 > p3) {
      return true;
    }

    // if last char not ' ', then not end field, like 'select count(*), su' can fill sum(
    if (sql[strlen(sql) - 1] != ' ' && cnt <= 1) {
      return false;
    }
  }

  char* p4 = strrchr(sql, ' ');
  if (p4 == NULL) {
    // only one word
    return false;
  }

  return true;
}

// need insert from
bool needInsertFrom(char* sql, int len) {
  // last is blank
  if (sql[len - 1] != ' ') {
    // insert from keyword
    return false;
  }

  //  select fields input is end
  if (!fieldsInputEnd(sql)) {
    return false;
  }

  // can insert from keyword
  return true;
}

// p is string following select keyword
bool appendAfterSelect(TAOS* con, SShellCmd* cmd, char* sql, int32_t len) {
  char* p = strndup(sql, len);

  // union all
  char* p1;
  do {
    p1 = strstr(p, UNION_ALL);
    if (p1) {
      p = p1 + strlen(UNION_ALL);
    }
  } while (p1);

  char* from = strstr(p, " from ");
  // last word , maybe empty string or some letters of a string
  char* last = lastWord(p);
  bool  ret = false;
  if (from == NULL) {
    bool fieldEnd = fieldsInputEnd(p);
    // check fields input end then insert from keyword
    if (fieldEnd && p[len - 1] == ' ') {
      shellInsertStr(cmd, "from", 4);
      taosMemoryFree(p);
      return true;
    }

    // fill function
    if (fieldEnd) {
      // fields is end , need match keyword
      ret = fillWithType(con, cmd, last, WT_VAR_KEYWORD);
    } else {
      ret = fillWithType(con, cmd, last, WT_VAR_FUNC);
    }

    taosMemoryFree(p);
    return ret;
  }

  // have from
  char* blank = strstr(from + 6, " ");
  if (blank == NULL) {
    // no table name, need fill
    ret = fillTableName(con, cmd, last);
  } else {
    ret = fillWithType(con, cmd, last, WT_VAR_KEYWORD);
  }

  taosMemoryFree(p);
  return ret;
}

int32_t searchAfterSelect(char* p, int32_t len) {
  // select * from st;
  if (strncasecmp(p, "select ", 7) == 0) {
    // check nest query
    char* p1 = p + 7;
    while (1) {
      char* p2 = strstr(p1, "select ");
      if (p2 == NULL) break;
      p1 = p2 + 7;
    }

    return p1 - p;
  }

  // explain as select * from st;
  if (strncasecmp(p, "explain select ", 15) == 0) {
    return 15;
  }

  char* as_pos_end = strstr(p, " as select ");
  if (as_pos_end == NULL) return -1;
  as_pos_end += 11;

  // create stream <stream_name> as select
  if (strncasecmp(p, "create stream ", 14) == 0) {
    return as_pos_end - p;
    ;
  }

  // create topic <topic_name> as select
  if (strncasecmp(p, "create topic ", 13) == 0) {
    return as_pos_end - p;
  }

  return -1;
}

bool matchSelectQuery(TAOS* con, SShellCmd* cmd) {
  // if continue press Tab , delete bytes by previous autofill
  if (cntDel > 0) {
    deleteCount(cmd, cntDel);
    cntDel = 0;
  }

  // match select ...
  int   len = cmd->commandSize;
  char* p = cmd->command;

  // remove prefix blank
  while (p[0] == ' ' && len > 0) {
    p++;
    len--;
  }

  // special range
  if (len < 7 || len > 512) {
    return false;
  }

  // search
  char*   sql_cp = strndup(p, len);
  int32_t n = searchAfterSelect(sql_cp, len);
  taosMemoryFree(sql_cp);
  if (n == -1 || n > len) return false;
  p += n;
  len -= n;

  // append
  return appendAfterSelect(con, cmd, p, len);
}

// if is input create fields or tags area, return true
bool isCreateFieldsArea(char* p) {
  // put to while, support like create table st(ts timestamp, bin1 binary(16), bin2 + blank + TAB
  char* p1 = taosStrdup(p);
  bool  ret = false;
  while (1) {
    char* left = strrchr(p1, '(');
    if (left == NULL) {
      // like 'create table st'
      ret = false;
      break;
    }

    char* right = strrchr(p1, ')');
    if (right == NULL) {
      // like 'create table st( '
      ret = true;
      break;
    }

    if (left > right) {
      // like 'create table st( ts timestamp, age int) tags(area '
      ret = true;
      break;
    }

    // set string end by small for next strrchr search
    *left = 0;
  }
  taosMemoryFree(p1);

  return ret;
}

bool matchCreateTable(TAOS* con, SShellCmd* cmd) {
  // if continue press Tab , delete bytes by previous autofill
  if (cntDel > 0) {
    deleteCount(cmd, cntDel);
    cntDel = 0;
  }

  // match select ...
  int   len = cmd->commandSize;
  char* p = cmd->command;

  // remove prefix blank
  while (p[0] == ' ' && len > 0) {
    p++;
    len--;
  }

  // special range
  if (len < 7 || len > 1024) {
    return false;
  }

  // select and from
  if (strncasecmp(p, "create table ", 13) != 0) {
    // not select query clause
    return false;
  }
  p += 13;
  len -= 13;

  char* ps = strndup(p, len);
  bool  ret = false;
  char* last = lastWord(ps);

  // check in create fields or tags input area
  if (isCreateFieldsArea(ps)) {
    ret = fillWithType(con, cmd, last, WT_VAR_DATATYPE);
  }

  // tags
  if (!ret) {
    // find only one ')' , can insert tags
    char* p1 = strchr(ps, ')');
    if (p1) {
      if (strchr(p1 + 1, ')') == NULL && strstr(p1 + 1, "tags") == NULL) {
        // can insert tags keyword
        ret = fillWithType(con, cmd, last, WT_VAR_KEYTAGS);
      }
    }
  }

  // tb options
  if (!ret) {
    // find like create table st (...) tags(..)  <here is fill tb option area>
    char* p1 = strchr(ps, ')');  // first ')' end
    if (p1) {
      if (strchr(p1 + 1, ')')) {  // second ')' end
        // here is tb options area, can insert option
        ret = fillWithType(con, cmd, last, WT_VAR_TBOPTION);
      }
    }
  }

  taosMemoryFree(ps);
  return ret;
}

bool matchOther(TAOS* con, SShellCmd* cmd) {
  int   len = cmd->commandSize;
  char* p = cmd->command;

  // '\\'
  if (p[len - 1] == '\\') {
    // append '\G'
    char a[] = "G;";
    shellInsertStr(cmd, a, 2);
    return true;
  }

  // too small
  if (len < 8) return false;

  // like 'from ( '
  char* sql = strndup(p, len);
  char* last = lastWord(sql);

  if (strcmp(last, "from(") == 0) {
    fillWithType(con, cmd, "", WT_VAR_KEYSELECT);
    taosMemoryFree(sql);
    return true;
  }
  if (strncmp(last, "(", 1) == 0) {
    last += 1;
  }

  char* from = strstr(sql, " from");
  // find last ' from'
  while (from) {
    char* p1 = strstr(from + 5, " from");
    if (p1 == NULL) break;
    from = p1;
  }

  if (from) {
    // find next is '('
    char* p2 = from + 5;
    bool  found = false;   // found 'from ... ( ...'  ... is any count of blank
    bool  found1 = false;  // found '('
    while (1) {
      if (p2 == last || *p2 == '\0') {
        // last word or string end
        if (found1) {
          found = true;
        }
        break;
      } else if (*p2 == '(') {
        found1 = true;
      } else if (*p2 == ' ') {
        // do nothing
      } else {
        // have any other char
        break;
      }

      // move next
      p2++;
    }

    if (found) {
      fillWithType(con, cmd, last, WT_VAR_KEYSELECT);
      taosMemoryFree(sql);
      return true;
    }
  }

  // INSERT

  taosMemoryFree(sql);

  return false;
}

// last match if nothing matched
bool matchEnd(TAOS* con, SShellCmd* cmd) {
  // str dump
  bool  ret = false;
  char* ps = strndup(cmd->command, cmd->commandSize);
  char* last = lastWord(ps);
  char* elast = strrchr(last, '.');  // find end last
  if (elast) {
    last = elast + 1;
  }

  // less one char can match
  if (strlen(last) == 0) {
    goto _return;
  }
  if (strcmp(last, " ") == 0) {
    goto _return;
  }

  // match database
  if (elast == NULL) {
    // dot need not completed with dbname
    if (fillWithType(con, cmd, last, WT_VAR_DBNAME)) {
      ret = true;
      goto _return;
    }
  }

  if (fillWithType(con, cmd, last, WT_VAR_SYSTABLE)) {
    ret = true;
    goto _return;
  }

_return:
  taosMemoryFree(ps);
  return ret;
}

// main key press tab
void pressTabKey(SShellCmd* cmd) {
  // check empty tab key
  if (cmd->commandSize == 0) {
    // have multi line tab key
    if (cmd->bufferSize == 0) {
      showHelp();
    }
    shellShowOnScreen(cmd);
    return;
  }

  // save connection to global
  varCmd = cmd;
  bool matched = false;

  // manual match like create table st( ...
  matched = matchCreateTable(varCon, cmd);
  if (matched) return;

  // shellCommands match
  if (firstMatchIndex == -1) {
    matched = firstMatchCommand(varCon, cmd);
  } else {
    matched = nextMatchCommand(varCon, cmd, &shellCommands[firstMatchIndex]);
  }
  if (matched) return;

  // NOT MATCHED ANYONE
  // match other like '\G' ...
  matched = matchOther(varCon, cmd);
  if (matched) return;

  // manual match like select * from ...
  matched = matchSelectQuery(varCon, cmd);
  if (matched) return;

  // match end
  matched = matchEnd(varCon, cmd);

  return;
}

// press othr key
void pressOtherKey(char c) {
  // reset global variant
  firstMatchIndex = -1;
  lastMatchIndex = -1;
  curMatchIndex = -1;
  lastWordBytes = -1;

  // var names
  cursorVar = -1;
  varMode = false;
  waitAutoFill = false;
  cntDel = 0;

  if (lastMatch) {
    freeMatch(lastMatch);
    lastMatch = NULL;
  }
}

// put name into name, return name length
int getWordName(char* p, char* name, int nameLen) {
  // remove prefix blank
  while (*p == ' ') {
    p++;
  }

  // get databases name;
  int i = 0;
  while (p[i] != 0 && i < nameLen - 1) {
    name[i] = p[i];
    i++;
    if (p[i] == ' ' || p[i] == ';' || p[i] == '(') {
      // name end
      break;
    }
  }
  name[i] = 0;

  return i;
}

// deal use db, if have  'use' return true
bool dealUseDB(char* sql) {
  // check use keyword
  if (strncasecmp(sql, "use ", 4) != 0) {
    return false;
  }

  char  db[256];
  char* p = sql + 4;
  if (getWordName(p, db, sizeof(db)) == 0) {
    // no name , return
    return true;
  }

  //  dbName is previous use open db name
  if (strcasecmp(db, dbName) == 0) {
    // same , no need switch
    return true;
  }

  // switch new db
  taosThreadMutexLock(&tiresMutex);
  // STABLE set null
  STire* tire = tires[WT_VAR_STABLE];
  tires[WT_VAR_STABLE] = NULL;
  if (tire) {
    freeTire(tire);
  }
  // TABLE set null
  tire = tires[WT_VAR_TABLE];
  tires[WT_VAR_TABLE] = NULL;
  if (tire) {
    freeTire(tire);
  }
  // save
  strcpy(dbName, db);
  taosThreadMutexUnlock(&tiresMutex);

  return true;
}

// deal create, if have 'create' return true
bool dealCreateCommand(char* sql) {
  // check keyword
  if (strncasecmp(sql, "create ", 7) != 0) {
    return false;
  }

  char  name[1024];
  char* p = sql + 7;
  if (getWordName(p, name, sizeof(name)) == 0) {
    // no name , return
    return true;
  }

  int type = -1;
  //  dbName is previous use open db name
  if (strcasecmp(name, "database") == 0) {
    type = WT_VAR_DBNAME;
  } else if (strcasecmp(name, "table") == 0) {
    if (strstr(sql, " tags") != NULL && strstr(sql, " using ") == NULL)
      type = WT_VAR_STABLE;
    else
      type = WT_VAR_TABLE;
  } else if (strcasecmp(name, "user") == 0) {
    type = WT_VAR_USERNAME;
  } else if (strcasecmp(name, "topic") == 0) {
    type = WT_VAR_TOPIC;
  } else if (strcasecmp(name, "stream") == 0) {
    type = WT_VAR_STREAM;
  } else {
    // no match , return
    return true;
  }

  // move next
  p += strlen(name);

  // get next word , that is table name
  if (getWordName(p, name, sizeof(name)) == 0) {
    // no name , return
    return true;
  }

  // switch new db
  taosThreadMutexLock(&tiresMutex);
  // STABLE set null
  STire* tire = tires[type];
  if (tire) {
    insertWord(tire, name);
  }
  taosThreadMutexUnlock(&tiresMutex);

  return true;
}

// deal create, if have 'drop' return true
bool dealDropCommand(char* sql) {
  // check keyword
  if (strncasecmp(sql, "drop ", 5) != 0) {
    return false;
  }

  char  name[1024];
  char* p = sql + 5;
  if (getWordName(p, name, sizeof(name)) == 0) {
    // no name , return
    return true;
  }

  int type = -1;
  //  dbName is previous use open db name
  if (strcasecmp(name, "database") == 0) {
    type = WT_VAR_DBNAME;
  } else if (strcasecmp(name, "table") == 0) {
    type = WT_VAR_ALLTABLE;
  } else if (strcasecmp(name, "dnode") == 0) {
    type = WT_VAR_DNODEID;
  } else if (strcasecmp(name, "user") == 0) {
    type = WT_VAR_USERNAME;
  } else if (strcasecmp(name, "topic") == 0) {
    type = WT_VAR_TOPIC;
  } else if (strcasecmp(name, "stream") == 0) {
    type = WT_VAR_STREAM;
  } else {
    // no match , return
    return true;
  }

  // move next
  p += strlen(name);

  // get next word , that is table name
  if (getWordName(p, name, sizeof(name)) == 0) {
    // no name , return
    return true;
  }

  // switch new db
  taosThreadMutexLock(&tiresMutex);
  // STABLE set null
  if (type == WT_VAR_ALLTABLE) {
    bool del = false;
    // del in stable
    STire* tire = tires[WT_VAR_STABLE];
    if (tire) del = deleteWord(tire, name);
    // del in table
    if (!del) {
      tire = tires[WT_VAR_TABLE];
      if (tire) del = deleteWord(tire, name);
    }
  } else {
    // OTHER TYPE
    STire* tire = tires[type];
    if (tire) deleteWord(tire, name);
  }
  taosThreadMutexUnlock(&tiresMutex);

  return true;
}

// callback autotab module after shell sql execute
void callbackAutoTab(char* sqlstr, TAOS* pSql, bool usedb) {
  char* sql = sqlstr;
  // remove prefix blank
  while (*sql == ' ') {
    sql++;
  }

  if (dealUseDB(sql)) {
    // change to new db
    if (!varRunOnce) updateTireValue(WT_VAR_STABLE, false);
    return;
  }

  // create command add name to autotab
  if (dealCreateCommand(sql)) {
    return;
  }

  // drop command remove name from autotab
  if (dealDropCommand(sql)) {
    return;
  }

  return;
}