content: /*
   * Copyright (C) 2016-2023 ActionTech.
   * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
   */
  
  package com.actiontech.dble.services.manager.response;
  
  import com.actiontech.dble.DbleServer;
  import com.actiontech.dble.backend.datasource.ShardingNode;
  import com.actiontech.dble.backend.mysql.PacketUtil;
  import com.actiontech.dble.config.ErrorCode;
  import com.actiontech.dble.config.Fields;
  import com.actiontech.dble.config.model.db.DbInstanceConfig;
  import com.actiontech.dble.config.model.sharding.SchemaConfig;
  import com.actiontech.dble.config.model.sharding.table.BaseTableConfig;
  import com.actiontech.dble.net.mysql.*;
  import com.actiontech.dble.services.manager.ManagerService;
  import com.actiontech.dble.singleton.ProxyMeta;
  import com.actiontech.dble.util.LongUtil;
  import com.actiontech.dble.util.StringUtil;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.regex.Matcher;
  
  import static com.actiontech.dble.route.parser.ManagerParseShow.PATTERN_FOR_TABLE_INFO;
  
  public final class ShowTableShardingNode {
      private ShowTableShardingNode() {
      }
  
      private static final int FIELD_COUNT = 7;
      private static final ResultSetHeaderPacket HEADER = PacketUtil.getHeader(FIELD_COUNT);
      private static final FieldPacket[] FIELDS = new FieldPacket[FIELD_COUNT];
      private static final EOFPacket EOF = new EOFPacket();
  
      static {
          int i = 0;
          byte packetId = 0;
          HEADER.setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("NAME", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("SEQUENCE", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("HOST", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PORT", Fields.FIELD_TYPE_LONG);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PHYSICAL_SCHEMA", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("USER", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
  
          FIELDS[i] = PacketUtil.getField("PASSWORD", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i].setPacketId(++packetId);
  
          EOF.setPacketId(++packetId);
      }
  
      public static void execute(ManagerService service, String tableInfo) {
          Matcher ma = PATTERN_FOR_TABLE_INFO.matcher(tableInfo);
          if (!ma.matches()) {
              service.writeErrMessage(ErrorCode.ER_UNKNOWN_ERROR, "The Correct Query Format Is:show @@shardingnodes where schema='?' and table ='?'");
              return;
          }
          String schemaName = StringUtil.removeAllApostrophe(ma.group(1));
          String tableName = StringUtil.removeAllApostrophe(ma.group(5));
          if (DbleServer.getInstance().getSystemVariables().isLowerCaseTableNames()) {
              schemaName = schemaName.toLowerCase();
              tableName = tableName.toLowerCase();
          }
  
          SchemaConfig schemaConfig = DbleServer.getInstance().getConfig().getSchemas().get(schemaName);
          List<String> shardingNodes = null;
          if (schemaConfig == null) {
              service.writeErrMessage(ErrorCode.ER_UNKNOWN_ERROR, "the schema [" + schemaName + "] does not exists");
              return;
          } else if (schemaConfig.isNoSharding()) {
              if (ProxyMeta.getInstance().getTmManager().checkTableExists(schemaName, tableName)) {
                  shardingNodes = Collections.singletonList(schemaConfig.getDefaultSingleNode());
              }
          } else {
              BaseTableConfig tableConfig = schemaConfig.getTables().get(tableName);
              if (tableConfig == null) {
                  if (schemaConfig.getDefaultShardingNodes() == null) {
                      service.writeErrMessage(ErrorCode.ER_UNKNOWN_ERROR, "the table [" + tableName + "] in schema [" + schemaName + "] does not exists");
                      return;
                  } else if (ProxyMeta.getInstance().getTmManager().checkTableExists(schemaName, tableName)) {
                      shardingNodes = schemaConfig.getDefaultShardingNodes();
                  }
              } else {
                  shardingNodes = tableConfig.getShardingNodes();
              }
          }
          ByteBuffer buffer = service.allocate();
  
          // write header
          buffer = HEADER.write(buffer, service, true);
  
          // write fields
          for (FieldPacket field : FIELDS) {
              buffer = field.write(buffer, service, true);
          }
  
          // write eof
          buffer = EOF.write(buffer, service, true);
  
          // write rows
          byte packetId = EOF.getPacketId();
  
          if (shardingNodes != null) {
              for (RowDataPacket row : getRows(shardingNodes, service.getCharset().getResults())) {
                  row.setPacketId(++packetId);
                  buffer = row.write(buffer, service, true);
              }
          }
  
          // write last eof
          EOFRowPacket lastEof = new EOFRowPacket();
          lastEof.setPacketId(++packetId);
  
  
          lastEof.write(buffer, service);
      }
  
      private static List<RowDataPacket> getRows(List<String> shardingNodes, String charset) {
          List<RowDataPacket> list = new ArrayList<>();
          int sequence = 0;
          for (String shardingNode : shardingNodes) {
              ShardingNode dn = DbleServer.getInstance().getConfig().getShardingNodes().get(shardingNode);
              DbInstanceConfig dbConfig = dn.getDbGroup().getWriteDbInstance().getConfig();
              RowDataPacket row = new RowDataPacket(FIELD_COUNT);
              row.add(StringUtil.encode(dn.getName(), charset));
              row.add(LongUtil.toBytes(sequence));
              row.add(StringUtil.encode(dbConfig.getIp(), charset));
              row.add(LongUtil.toBytes(dbConfig.getPort()));
              row.add(StringUtil.encode(dn.getDatabase(), charset));
              row.add(StringUtil.encode(dbConfig.getUser(), charset));
              row.add(StringUtil.encode(dbConfig.getPassword(), charset));
              list.add(row);
              sequence++;
          }
          return list;
      }
  }
  