content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * based on code by MyCATCopyrightHolder Copyright (c) 2013, OpenCloudDB/MyCAT.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  package com.actiontech.dble.route.parser;
  
  import com.actiontech.dble.route.parser.util.ParseUtil;
  
  /**
   * @author mycat
   */
  public final class ManagerParseClear {
      private ManagerParseClear() {
      }
  
      public static final int OTHER = -1;
      public static final int SLOW_SCHEMA = 1;
      public static final int SLOW_DATANODE = 2;
  
      public static int parse(String stmt, int offset) {
          int i = offset;
          for (; i < stmt.length(); i++) {
              switch (stmt.charAt(i)) {
                  case ' ':
                      continue;
                  case '/':
                  case '#':
                      i = ParseUtil.comment(stmt, i);
                      continue;
                  case '@':
                      return clear2Check(stmt, i);
                  default:
                      return OTHER;
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW
      static int clear2Check(String stmt, int offset) {
          if (stmt.length() > ++offset && stmt.charAt(offset) == '@' &&
                  stmt.length() > offset + "SLOW ".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              if ((c1 == 'S' || c1 == 's') && (c2 == 'L' || c2 == 'l') && (c3 == 'O' || c3 == 'o') &&
                      (c4 == 'W' || c4 == 'w') && (c5 == ' ')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                          case ' ':
                              continue;
                          case 'W':
                          case 'w':
                              return clear2WhereCheck(stmt, offset);
                          default:
                              return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE
      static int clear2WhereCheck(String stmt, int offset) {
          if (stmt.length() > offset + "HERE ".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              if ((c1 == 'H' || c1 == 'h') && (c2 == 'E' || c2 == 'e') && (c3 == 'R' || c3 == 'r') &&
                      (c4 == 'E' || c4 == 'e') && (c5 == ' ')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                          case ' ':
                              continue;
                          case 'D':
                          case 'd':
                              return clear2DCheck(stmt, offset);
                          case 'S':
                          case 's':
                              return clear2SCheck(stmt, offset);
                          default:
                              return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE DATANODE = XXXXXX
      static int clear2DCheck(String stmt, int offset) {
          if (stmt.length() > offset + "ATANODE".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              char c6 = stmt.charAt(++offset);
              char c7 = stmt.charAt(++offset);
              if ((c1 == 'A' || c1 == 'a') && (c2 == 'T' || c2 == 't') && (c3 == 'A' || c3 == 'a') &&
                      (c4 == 'N' || c4 == 'n') && (c5 == 'O' || c5 == 'o') && (c6 == 'D' || c6 == 'd') &&
                      (c7 == 'E' || c7 == 'e')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                          case ' ':
                              continue;
                          case '=':
                              while (stmt.length() > ++offset) {
                                  switch (stmt.charAt(offset)) {
                                      case ' ':
                                          continue;
                                      default:
                                          return (offset << 8) | SLOW_DATANODE;
                                  }
                              }
                              return OTHER;
                          default:
                              return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
      // CLEAR @@SLOW WHERE SCHEMA = XXXXXX
      static int clear2SCheck(String stmt, int offset) {
          if (stmt.length() > offset + "CHEMA".length()) {
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              char c5 = stmt.charAt(++offset);
              if ((c1 == 'C' || c1 == 'c') && (c2 == 'H' || c2 == 'h') && (c3 == 'E' || c3 == 'e') &&
                      (c4 == 'M' || c4 == 'm') && (c5 == 'A' || c5 == 'a')) {
                  while (stmt.length() > ++offset) {
                      switch (stmt.charAt(offset)) {
                          case ' ':
                              continue;
                          case '=':
                              while (stmt.length() > ++offset) {
                                  switch (stmt.charAt(offset)) {
                                      case ' ':
                                          continue;
                                      default:
                                          return (offset << 8) | SLOW_SCHEMA;
                                  }
                              }
                              return OTHER;
                          default:
                              return OTHER;
                      }
                  }
              }
          }
          return OTHER;
      }
  
  }
  