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.server.parser;
  
  import com.actiontech.dble.route.parser.util.ParseUtil;
  
  /**
   * @author mycat
   */
  public class ServerParseStart {
      public ServerParseStart() {
      }
  
      public 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 'T':
                  case 't':
                      return transactionCheck(stmt, i);
                  default:
                      return ServerParse.OTHER;
              }
          }
          return ServerParse.OTHER;
      }
  
      protected int transactionCheck(String stmt, int offset) {
          if (stmt.length() > offset + 10) {
              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);
              char c8 = stmt.charAt(++offset);
              char c9 = stmt.charAt(++offset);
              char c10 = stmt.charAt(++offset);
              if ((c1 == 'R' || c1 == 'r') && (c2 == 'A' || c2 == 'a') && (c3 == 'N' || c3 == 'n') &&
                      (c4 == 'S' || c4 == 's') && (c5 == 'A' || c5 == 'a') && (c6 == 'C' || c6 == 'c') &&
                      (c7 == 'T' || c7 == 't') && (c8 == 'I' || c8 == 'i') && (c9 == 'O' || c9 == 'o') &&
                      (c10 == 'N' || c10 == 'n')) {
                  if (stmt.length() == ++offset)
                      return ServerParse.START_TRANSACTION;
                  int currentOffset = ParseUtil.skipSpace(stmt, offset);
                  if (stmt.length() == currentOffset) {
                      return ServerParse.START_TRANSACTION;
                  } else {
                      int currentOffset2 = ParseUtil.commentHint(stmt, currentOffset);
                      if (stmt.length() == ++currentOffset2 || stmt.length() == ParseUtil.skipSpace(stmt, currentOffset2)) {
                          return ServerParse.START_TRANSACTION;
                      } else {
                          return transactionReadCheck0(stmt, currentOffset);
                      }
                  }
              }
          }
          return ServerParse.OTHER;
      }
  
      protected int transactionReadCheck0(String stmt, int offset) {
          if (stmt.length() >= offset + "read ".length()) {
              char c0 = stmt.charAt(offset);
              char c1 = stmt.charAt(++offset);
              char c2 = stmt.charAt(++offset);
              char c3 = stmt.charAt(++offset);
              char c4 = stmt.charAt(++offset);
              if ((c0 == 'R' || c0 == 'r') && (c1 == 'E' || c1 == 'e') && (c2 == 'A' || c2 == 'a') &&
                      (c3 == 'D' || c3 == 'd') && ParseUtil.isSpace(c4)) {
                  return ServerParse.UNSUPPORT;
              }
          }
          return ServerParse.OTHER;
      }
  }
  