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.services.manager.response;
  
  import com.actiontech.dble.DbleServer;
  import com.actiontech.dble.backend.heartbeat.HeartbeatSQLJob;
  import com.actiontech.dble.backend.mysql.PacketUtil;
  import com.actiontech.dble.backend.mysql.nio.handler.ResponseHandler;
  import com.actiontech.dble.config.ErrorCode;
  import com.actiontech.dble.config.Fields;
  import com.actiontech.dble.net.IOProcessor;
  import com.actiontech.dble.net.connection.BackendConnection;
  import com.actiontech.dble.net.connection.PooledConnection;
  import com.actiontech.dble.net.mysql.*;
  import com.actiontech.dble.net.service.AuthService;
  import com.actiontech.dble.route.parser.util.DruidUtil;
  import com.actiontech.dble.services.manager.ManagerService;
  import com.actiontech.dble.services.mysqlsharding.MySQLResponseService;
  import com.actiontech.dble.util.*;
  import com.alibaba.druid.sql.ast.SQLExpr;
  import com.alibaba.druid.sql.ast.SQLStatement;
  import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
  
  import java.nio.ByteBuffer;
  import java.sql.SQLSyntaxErrorException;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * ShowBackend
   *
   * @author mycat
   */
  public final class ShowBackend {
      private static final int FIELD_COUNT = 23;
      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("processor", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("BACKEND_ID", Fields.FIELD_TYPE_LONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("MYSQLID", Fields.FIELD_TYPE_LONG);
          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("LOCAL_TCP_PORT", Fields.FIELD_TYPE_LONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("NET_IN", Fields.FIELD_TYPE_LONGLONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("NET_OUT", Fields.FIELD_TYPE_LONGLONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("ACTIVE_TIME(S)", Fields.FIELD_TYPE_LONGLONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("CLOSED", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          // fields[i] = PacketUtil.getField("run", Fields.FIELD_TYPE_VAR_STRING);
          // fields[i++].packetId = ++packetId;
          FIELDS[i] = PacketUtil.getField("STATE", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("SEND_QUEUE", Fields.FIELD_TYPE_LONG);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("SCHEMA", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("CHARACTER_SET_CLIENT", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("COLLATION_CONNECTION", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("CHARACTER_SET_RESULTS", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("TX_ISOLATION_LEVEL", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("AUTOCOMMIT", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("SYS_VARIABLES", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("USER_VARIABLES", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("XA_STATUS", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("DEAD_TIME", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i++].setPacketId(++packetId);
          FIELDS[i] = PacketUtil.getField("USED_FOR_HEARTBEAT", Fields.FIELD_TYPE_VAR_STRING);
          FIELDS[i].setPacketId(++packetId);
  
          EOF.setPacketId(++packetId);
      }
  
      private ShowBackend() {
      }
  
      public static void execute(ManagerService service, String whereCondition) {
          Map<String, String> whereInfo = new HashMap<>(8);
          if (!StringUtil.isEmpty(whereCondition)) {
              SQLStatement statement;
              try {
                  statement = DruidUtil.parseMultiSQL("select 1 " + whereCondition);
                  SQLExpr whereExpr = ((SQLSelectStatement) statement).getSelect().getQueryBlock().getWhere();
                  ShowConnection.getWhereCondition(whereExpr, whereInfo);
              } catch (SQLSyntaxErrorException e) {
                  service.writeErrMessage(ErrorCode.ER_PARSE_ERROR, "The sql has error syntax.");
                  return;
              }
          }
  
          ByteBuffer buffer = service.allocate();
          buffer = HEADER.write(buffer, service, true);
          for (FieldPacket field : FIELDS) {
              buffer = field.write(buffer, service, true);
          }
          buffer = EOF.write(buffer, service, true);
          byte packetId = EOF.getPacketId();
  
          IOProcessor[] processors = null;
          // return row
          if (!whereInfo.isEmpty() && whereInfo.get("processor") != null) {
              for (IOProcessor nioProcessor : DbleServer.getInstance().getBackendProcessors()) {
                  if (nioProcessor.getName().equals(whereInfo.get("processor"))) {
                      processors = new IOProcessor[1];
                      processors[0] = nioProcessor;
                      whereInfo.remove("processor");
                      break;
                  }
              }
          } else {
              processors = DbleServer.getInstance().getBackendProcessors();
          }
  
          if (processors == null) {
              EOFRowPacket lastEof = new EOFRowPacket();
              lastEof.setPacketId(++packetId);
  
              lastEof.write(buffer, service);
              return;
          }
  
          for (IOProcessor p : processors) {
              if (!whereInfo.isEmpty() && whereInfo.get("backend_id") != null) {
                  BackendConnection bc = p.getBackends().get(Long.parseLong(whereInfo.get("backend_id")));
                  if (bc == null) {
                      continue;
                  }
                  whereInfo.remove("backend_id");
                  if (whereInfo.isEmpty() || checkConn(bc, whereInfo)) {
                      RowDataPacket row = getRow(bc, service.getCharset().getResults());
                      if (row != null) {
                          row.setPacketId(++packetId);
                          buffer = row.write(buffer, service, true);
                      }
                  }
                  break;
              }
  
              for (BackendConnection bc : p.getBackends().values()) {
                  if (bc != null && (whereInfo.isEmpty() || checkConn(bc, whereInfo))) {
                      RowDataPacket row = getRow(bc, service.getCharset().getResults());
                      if (row != null) {
                          row.setPacketId(++packetId);
                          buffer = row.write(buffer, service, true);
                      }
                  }
              }
          }
  
          EOFRowPacket lastEof = new EOFRowPacket();
          lastEof.setPacketId(++packetId);
  
          lastEof.write(buffer, service);
      }
  
      private static boolean checkConn(BackendConnection bc, Map<String, String> whereInfo) {
          boolean isMatch = true;
          if (whereInfo.get("host") != null) {
              isMatch = bc.getHost().equals(whereInfo.get("host"));
          }
          if (whereInfo.get("port") != null) {
              isMatch = isMatch && String.valueOf(bc.getPort()).equals(whereInfo.get("port"));
          }
          if (whereInfo.get("mysqlid") != null) {
              isMatch = isMatch && String.valueOf(bc.getThreadId()).equals(whereInfo.get("mysqlid"));
          }
          return isMatch;
      }
  
      private static RowDataPacket getRow(BackendConnection c, String charset) {
          RowDataPacket row = new RowDataPacket(FIELD_COUNT);
          if (c.getService() instanceof AuthService) {
              return null;
          }
          int state = c.getState();
          row.add(c.getProcessor().getName().getBytes());
          row.add(LongUtil.toBytes(c.getId()));
          row.add(LongUtil.toBytes(c.getThreadId()));
          row.add(StringUtil.encode(c.getHost(), charset));
          row.add(IntegerUtil.toBytes(c.getPort()));
          row.add(IntegerUtil.toBytes(c.getLocalPort()));
          row.add(LongUtil.toBytes(c.getNetInBytes()));
          row.add(LongUtil.toBytes(c.getNetOutBytes()));
          row.add(LongUtil.toBytes((TimeUtil.currentTimeMillis() - c.getStartupTime()) / 1000L));
          row.add(c.isClosed() ? "true".getBytes() : "false".getBytes());
          row.add(stateStr(state).getBytes());
          row.add(IntegerUtil.toBytes(c.getWriteQueue().size()));
          row.add((c.getSchema() == null ? "NULL" : c.getSchema()).getBytes());
          MySQLResponseService backendService = c.getBackendService();
          boolean isNull = null == backendService;
          row.add(isNull ? null : backendService.getCharset().getClient().getBytes());
          row.add(isNull ? null : backendService.getCharset().getCollation().getBytes());
          row.add(isNull ? null : backendService.getCharset().getResults().getBytes());
          row.add(isNull ? null : (backendService.getTxIsolation() + "").getBytes());
          row.add(isNull ? null : (backendService.isAutocommit() + "").getBytes());
          row.add(isNull ? null : StringUtil.encode(backendService.getStringOfSysVariables(), charset));
          row.add(isNull ? null : StringUtil.encode(backendService.getStringOfUsrVariables(), charset));
          row.add(isNull ? null : StringUtil.encode(backendService.getXaStatus().toString(), charset));
          row.add(StringUtil.encode(FormatUtil.formatDate(c.getPoolDestroyedTime()), charset));
          if (isNull) {
              row.add(null);
          } else if (state == PooledConnection.INITIAL) {
              ResponseHandler handler = c.getBackendService().getResponseHandler();
              row.add(handler instanceof HeartbeatSQLJob ? "true".getBytes() : "false".getBytes());
          } else {
              row.add("false".getBytes());
          }
          return row;
      }
  
      public static String stateStr(int state) {
          switch (state) {
              case PooledConnection.STATE_IN_USE:
                  return "IN USE";
              case PooledConnection.STATE_NOT_IN_USE:
                  return "IDLE";
              case PooledConnection.STATE_REMOVED:
                  return "REMOVED";
              case PooledConnection.STATE_HEARTBEAT:
                  return "HEARTBEAT CHECK";
              case PooledConnection.STATE_RESERVED:
                  return "EVICT";
              case PooledConnection.INITIAL:
                  return "IN CREATION OR OUT OF POOL";
              default:
                  return "UNKNOWN STATE";
          }
      }
  }
  