text: import time
  from datetime import datetime, timedelta
  from decimal import Decimal
  import mysql.connector
  from multiprocessing import Pool
  import random
  import config
  
  
  ########################################################################################################################
  # PROCEDURES
  # Step 1: get all spaces
  # Step 2: Create multiprocessing pool to call worker in parallel
  ########################################################################################################################
  
  
  def main(logger):
  
      while True:
          # the outermost while loop
          ################################################################################################################
          # Step 1: get all spaces
          ################################################################################################################
          cnx_system_db = None
          cursor_system_db = None
          try:
              cnx_system_db = mysql.connector.connect(**config.myems_system_db)
              cursor_system_db = cnx_system_db.cursor()
          except Exception as e:
              logger.error("Error in step 1.1 of space_energy_input_item.main " + str(e))
              if cursor_system_db:
                  cursor_system_db.close()
              if cnx_system_db:
                  cnx_system_db.close()
              # sleep and continue the outer loop to reconnect the database
              time.sleep(60)
              continue
          print("Connected to MyEMS System Database")
  
          try:
              cursor_system_db.execute(" SELECT id, name "
                                       " FROM tbl_spaces "
                                       " ORDER BY id ")
              rows_spaces = cursor_system_db.fetchall()
  
              if rows_spaces is None or len(rows_spaces) == 0:
                  print("There isn't any spaces ")
                  # sleep and continue the outer loop to reconnect the database
                  time.sleep(60)
                  continue
  
              space_list = list()
              for row in rows_spaces:
                  space_list.append({"id": row[0], "name": row[1]})
  
          except Exception as e:
              logger.error("Error in step 1.2 of space_energy_input_item.main " + str(e))
              # sleep and continue the outer loop to reconnect the database
              time.sleep(60)
              continue
          finally:
              if cursor_system_db:
                  cursor_system_db.close()
              if cnx_system_db:
                  cnx_system_db.close()
  
          print("Got all spaces in MyEMS System Database")
  
          # shuffle the space list for randomly calculating the meter hourly value
          random.shuffle(space_list)
  
          ################################################################################################################
          # Step 2: Create multiprocessing pool to call worker in parallel
          ################################################################################################################
          p = Pool(processes=config.pool_size)
          error_list = p.map(worker, space_list)
          p.close()
          p.join()
  
          for error in error_list:
              if error is not None and len(error) > 0:
                  logger.error(error)
  
          print("go to sleep 300 seconds...")
          time.sleep(300)
          print("wake from sleep, and continue to work...")
      # end of outer while
  
  
  ########################################################################################################################
  # PROCEDURES:
  #   Step 1: get all input meters associated with the space
  #   Step 2: get all input virtual meters associated with the space
  #   Step 3: get all input offline meters associated with the space
  #   Step 4: get all combined equipments associated with the space
  #   Step 5: get all equipments associated with the space
  #   Step 6: get all shopfloors associated with the space
  #   Step 7: get all stores associated with the space
  #   Step 8: get all tenants associated with the space
  #   Step 9: get all child spaces associated with the space
  #   Step 10: determine start datetime and end datetime to aggregate
  #   Step 11: for each meter in list, get energy input data from energy database
  #   Step 12: for each virtual meter in list, get energy input data from energy database
  #   Step 13: for each offline meter in list, get energy input data from energy database
  #   Step 14: for each combined equipment in list, get energy input data from energy database
  #   Step 15: for each equipment in list, get energy input data from energy database
  #   Step 16: for each shopfloor in list, get energy input data from energy database
  #   Step 17: for each store in list, get energy input data from energy database
  #   Step 18: for each tenant in list, get energy input data from energy database
  #   Step 19: for each child space in list, get energy input data from energy database
  #   Step 20: determine common time slot to aggregate
  #   Step 21: aggregate energy data in the common time slot by energy items and hourly
  #   Step 22: save energy data to energy database
  #
  # NOTE: returns None or the error string because that the logger object cannot be passed in as parameter
  ########################################################################################################################
  
  def worker(space):
      ####################################################################################################################
      # Step 1: get all input meters associated with the space
      ####################################################################################################################
      print("Step 1: get all input meters associated with the space " + str(space['name']))
  
      cnx_system_db = None
      cursor_system_db = None
      try:
          cnx_system_db = mysql.connector.connect(**config.myems_system_db)
          cursor_system_db = cnx_system_db.cursor()
      except Exception as e:
          error_string = "Error in step 1.1 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      meter_list = list()
      try:
          cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "
                                   " FROM tbl_meters m, tbl_spaces_meters sm "
                                   " WHERE m.id = sm.meter_id "
                                   "       AND m.is_counted = true "
                                   "       AND m.energy_item_id is NOT NULL "
                                   "       AND sm.space_id = %s ",
                                   (space['id'],))
          rows_meters = cursor_system_db.fetchall()
  
          if rows_meters is not None and len(rows_meters) > 0:
              for row in rows_meters:
                  meter_list.append({"id": row[0],
                                     "name": row[1],
                                     "energy_item_id": row[2]})
  
      except Exception as e:
          error_string = "Error in step 1.2 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 2: get all input virtual meters associated with the space
      ####################################################################################################################
      print("Step 2: get all input virtual meters associated with the space")
      virtual_meter_list = list()
  
      try:
          cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "
                                   " FROM tbl_virtual_meters m, tbl_spaces_virtual_meters sm "
                                   " WHERE m.id = sm.virtual_meter_id "
                                   "       AND m.is_counted = true "
                                   "       AND m.energy_item_id is NOT NULL "
                                   "       AND sm.space_id = %s ",
                                   (space['id'],))
          rows_virtual_meters = cursor_system_db.fetchall()
  
          if rows_virtual_meters is not None and len(rows_virtual_meters) > 0:
              for row in rows_virtual_meters:
                  virtual_meter_list.append({"id": row[0],
                                             "name": row[1],
                                             "energy_item_id": row[2]})
  
      except Exception as e:
          error_string = "Error in step 2 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 3: get all input offline meters associated with the space
      ####################################################################################################################
      print("Step 3: get all input offline meters associated with the space")
  
      offline_meter_list = list()
  
      try:
          cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "
                                   " FROM tbl_offline_meters m, tbl_spaces_offline_meters sm "
                                   " WHERE m.id = sm.offline_meter_id "
                                   "       AND m.is_counted = true "
                                   "       AND m.energy_item_id is NOT NULL "
                                   "       AND sm.space_id = %s ",
                                   (space['id'],))
          rows_offline_meters = cursor_system_db.fetchall()
  
          if rows_offline_meters is not None and len(rows_offline_meters) > 0:
              for row in rows_offline_meters:
                  offline_meter_list.append({"id": row[0],
                                             "name": row[1],
                                             "energy_item_id": row[2]})
  
      except Exception as e:
          error_string = "Error in step 3 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 4: get all combined equipments associated with the space
      ####################################################################################################################
      print("Step 4: get all combined equipments associated with the space")
  
      combined_equipment_list = list()
  
      try:
          cursor_system_db.execute(" SELECT e.id, e.name "
                                   " FROM tbl_combined_equipments e, tbl_spaces_combined_equipments se "
                                   " WHERE e.id = se.combined_equipment_id "
                                   "       AND e.is_input_counted = true "
                                   "       AND se.space_id = %s ",
                                   (space['id'],))
          rows_combined_equipments = cursor_system_db.fetchall()
  
          if rows_combined_equipments is not None and len(rows_combined_equipments) > 0:
              for row in rows_combined_equipments:
                  combined_equipment_list.append({"id": row[0],
                                                  "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 4 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 5: get all equipments associated with the space
      ####################################################################################################################
      print("Step 5: get all equipments associated with the space")
  
      equipment_list = list()
  
      try:
          cursor_system_db.execute(" SELECT e.id, e.name "
                                   " FROM tbl_equipments e, tbl_spaces_equipments se "
                                   " WHERE e.id = se.equipment_id "
                                   "       AND e.is_input_counted = true "
                                   "       AND se.space_id = %s ",
                                   (space['id'],))
          rows_equipments = cursor_system_db.fetchall()
  
          if rows_equipments is not None and len(rows_equipments) > 0:
              for row in rows_equipments:
                  equipment_list.append({"id": row[0],
                                         "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 5 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 6: get all shopfloors associated with the space
      ####################################################################################################################
      print("Step 6: get all shopfloors associated with the space")
  
      shopfloor_list = list()
  
      try:
          cursor_system_db.execute(" SELECT s.id, s.name "
                                   " FROM tbl_shopfloors s, tbl_spaces_shopfloors ss "
                                   " WHERE s.id = ss.shopfloor_id "
                                   "       AND s.is_input_counted = true "
                                   "       AND ss.space_id = %s ",
                                   (space['id'],))
          rows_shopfloors = cursor_system_db.fetchall()
  
          if rows_shopfloors is not None and len(rows_shopfloors) > 0:
              for row in rows_shopfloors:
                  shopfloor_list.append({"id": row[0],
                                         "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 6 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 7: get all stores associated with the space
      ####################################################################################################################
      print("Step 7: get all stores associated with the space")
  
      store_list = list()
  
      try:
          cursor_system_db.execute(" SELECT s.id, s.name "
                                   " FROM tbl_stores s, tbl_spaces_stores ss "
                                   " WHERE s.id = ss.store_id "
                                   "       AND s.is_input_counted = true "
                                   "       AND ss.space_id = %s ",
                                   (space['id'],))
          rows_stores = cursor_system_db.fetchall()
  
          if rows_stores is not None and len(rows_stores) > 0:
              for row in rows_stores:
                  store_list.append({"id": row[0],
                                     "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 7 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 8: get all tenants associated with the space
      ####################################################################################################################
      print("Step 8: get all tenants associated with the space")
  
      tenant_list = list()
  
      try:
          cursor_system_db.execute(" SELECT t.id, t.name "
                                   " FROM tbl_tenants t, tbl_spaces_tenants st "
                                   " WHERE t.id = st.tenant_id "
                                   "       AND t.is_input_counted = true "
                                   "       AND st.space_id = %s ",
                                   (space['id'],))
          rows_tenants = cursor_system_db.fetchall()
  
          if rows_tenants is not None and len(rows_tenants) > 0:
              for row in rows_tenants:
                  tenant_list.append({"id": row[0],
                                      "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 8 of space_energy_input_item.worker " + str(e)
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 9: get all child spaces associated with the space
      ####################################################################################################################
      print("Step 9: get all child spaces associated with the space")
  
      child_space_list = list()
  
      try:
          cursor_system_db.execute(" SELECT id, name "
                                   " FROM tbl_spaces "
                                   " WHERE is_input_counted = true "
                                   "       AND parent_space_id = %s ",
                                   (space['id'],))
          rows_child_spaces = cursor_system_db.fetchall()
  
          if rows_child_spaces is not None and len(rows_child_spaces) > 0:
              for row in rows_child_spaces:
                  child_space_list.append({"id": row[0],
                                           "name": row[1]})
  
      except Exception as e:
          error_string = "Error in step 9 of space_energy_input_item.worker " + str(e)
          print(error_string)
          return error_string
      finally:
          if cursor_system_db:
              cursor_system_db.close()
          if cnx_system_db:
              cnx_system_db.close()
  
      if (meter_list is None or len(meter_list) == 0) and \
              (virtual_meter_list is None or len(virtual_meter_list) == 0) and \
              (offline_meter_list is None or len(offline_meter_list) == 0) and \
              (combined_equipment_list is None or len(combined_equipment_list) == 0) and \
              (equipment_list is None or len(equipment_list) == 0) and \
              (shopfloor_list is None or len(shopfloor_list) == 0) and \
              (store_list is None or len(store_list) == 0) and \
              (tenant_list is None or len(tenant_list) == 0) and \
              (child_space_list is None or len(child_space_list) == 0):
          print("This is an empty space ")
          return None
  
      ####################################################################################################################
      # Step 10: determine start datetime and end datetime to aggregate
      ####################################################################################################################
      print("Step 10: determine start datetime and end datetime to aggregate")
      cnx_energy_db = None
      cursor_energy_db = None
      try:
          cnx_energy_db = mysql.connector.connect(**config.myems_energy_db)
          cursor_energy_db = cnx_energy_db.cursor()
      except Exception as e:
          error_string = "Error in step 10.1 of space_energy_input_item.worker " + str(e)
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
          print(error_string)
          return error_string
  
      try:
          query = (" SELECT MAX(start_datetime_utc) "
                   " FROM tbl_space_input_item_hourly "
                   " WHERE space_id = %s ")
          cursor_energy_db.execute(query, (space['id'],))
          row_datetime = cursor_energy_db.fetchone()
          start_datetime_utc = datetime.strptime(config.start_datetime_utc, '%Y-%m-%d %H:%M:%S')
          start_datetime_utc = start_datetime_utc.replace(minute=0, second=0, microsecond=0, tzinfo=None)
  
          if row_datetime is not None and len(row_datetime) > 0 and isinstance(row_datetime[0], datetime):
              # replace second and microsecond with 0
              # note: do not replace minute in case of calculating in half hourly
              start_datetime_utc = row_datetime[0].replace(second=0, microsecond=0, tzinfo=None)
              # start from the next time slot
              start_datetime_utc += timedelta(minutes=config.minutes_to_count)
  
          end_datetime_utc = datetime.utcnow().replace(second=0, microsecond=0, tzinfo=None)
  
          print("start_datetime_utc: " + start_datetime_utc.isoformat()[0:19]
                + "end_datetime_utc: " + end_datetime_utc.isoformat()[0:19])
  
      except Exception as e:
          error_string = "Error in step 10.2 of space_energy_input_item.worker " + str(e)
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 11: for each meter in list, get energy input data from energy database
      ####################################################################################################################
      energy_meter_hourly = dict()
      try:
          if meter_list is not None and len(meter_list) > 0:
              for meter in meter_list:
                  meter_id = str(meter['id'])
  
                  query = (" SELECT start_datetime_utc, actual_value "
                           " FROM tbl_meter_hourly "
                           " WHERE meter_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (meter_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_meter_hourly[meter_id] = None
                  else:
                      energy_meter_hourly[meter_id] = dict()
                      for row_energy_value in rows_energy_values:
                          energy_meter_hourly[meter_id][row_energy_value[0]] = row_energy_value[1]
      except Exception as e:
          error_string = "Error in step 11 of space_energy_input_item.worker " + str(e)
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 12: for each virtual meter in list, get energy input data from energy database
      ####################################################################################################################
      energy_virtual_meter_hourly = dict()
      if virtual_meter_list is not None and len(virtual_meter_list) > 0:
          try:
              for virtual_meter in virtual_meter_list:
                  virtual_meter_id = str(virtual_meter['id'])
  
                  query = (" SELECT start_datetime_utc, actual_value "
                           " FROM tbl_virtual_meter_hourly "
                           " WHERE virtual_meter_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (virtual_meter_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_virtual_meter_hourly[virtual_meter_id] = None
                  else:
                      energy_virtual_meter_hourly[virtual_meter_id] = dict()
                      for row_energy_value in rows_energy_values:
                          energy_virtual_meter_hourly[virtual_meter_id][row_energy_value[0]] = row_energy_value[1]
          except Exception as e:
              error_string = "Error in step 12 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 13: for each offline meter in list, get energy input data from energy database
      ####################################################################################################################
      energy_offline_meter_hourly = dict()
      if offline_meter_list is not None and len(offline_meter_list) > 0:
          try:
              for offline_meter in offline_meter_list:
                  offline_meter_id = str(offline_meter['id'])
  
                  query = (" SELECT start_datetime_utc, actual_value "
                           " FROM tbl_offline_meter_hourly "
                           " WHERE offline_meter_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (offline_meter_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_offline_meter_hourly[offline_meter_id] = None
                  else:
                      energy_offline_meter_hourly[offline_meter_id] = dict()
                      for row_energy_value in rows_energy_values:
                          energy_offline_meter_hourly[offline_meter_id][row_energy_value[0]] = row_energy_value[1]
  
          except Exception as e:
              error_string = "Error in step 13 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 14: for each combined equipment in list, get energy input data from energy database
      ####################################################################################################################
      energy_combined_equipment_hourly = dict()
      if combined_equipment_list is not None and len(combined_equipment_list) > 0:
          try:
              for combined_equipment in combined_equipment_list:
                  combined_equipment_id = str(combined_equipment['id'])
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_combined_equipment_input_item_hourly "
                           " WHERE combined_equipment_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (combined_equipment_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_combined_equipment_hourly[combined_equipment_id] = None
                  else:
                      energy_combined_equipment_hourly[combined_equipment_id] = dict()
                      for row_value in rows_energy_values:
                          current_datetime_utc = row_value[0]
                          if current_datetime_utc not in energy_combined_equipment_hourly[combined_equipment_id]:
                              energy_combined_equipment_hourly[combined_equipment_id][current_datetime_utc] = dict()
                          energy_item_id = row_value[1]
                          actual_value = row_value[2]
                          energy_combined_equipment_hourly[combined_equipment_id][current_datetime_utc][energy_item_id] \
                              = actual_value
          except Exception as e:
              error_string = "Error in step 14 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 15: for each equipment in list, get energy input data from energy database
      ####################################################################################################################
      energy_equipment_hourly = dict()
      if equipment_list is not None and len(equipment_list) > 0:
          try:
              for equipment in equipment_list:
                  equipment_id = str(equipment['id'])
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_equipment_input_item_hourly "
                           " WHERE equipment_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (equipment_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_equipment_hourly[equipment_id] = None
                  else:
                      energy_equipment_hourly[equipment_id] = dict()
                      for row_value in rows_energy_values:
                          current_datetime_utc = row_value[0]
                          if current_datetime_utc not in energy_equipment_hourly[equipment_id]:
                              energy_equipment_hourly[equipment_id][current_datetime_utc] = dict()
                          energy_item_id = row_value[1]
                          actual_value = row_value[2]
                          energy_equipment_hourly[equipment_id][current_datetime_utc][energy_item_id] = \
                              actual_value
          except Exception as e:
              error_string = "Error in step 15 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 16: for each shopfloor in list, get energy input data from energy database
      ####################################################################################################################
      energy_shopfloor_hourly = dict()
      if shopfloor_list is not None and len(shopfloor_list) > 0:
          try:
              for shopfloor in shopfloor_list:
                  shopfloor_id = str(shopfloor['id'])
  
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_shopfloor_input_item_hourly "
                           " WHERE shopfloor_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (shopfloor_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_shopfloor_hourly[shopfloor_id] = None
                  else:
                      energy_shopfloor_hourly[shopfloor_id] = dict()
                      for row_energy_value in rows_energy_values:
                          current_datetime_utc = row_energy_value[0]
                          if current_datetime_utc not in energy_shopfloor_hourly[shopfloor_id]:
                              energy_shopfloor_hourly[shopfloor_id][current_datetime_utc] = dict()
                          energy_item_id = row_energy_value[1]
                          actual_value = row_energy_value[2]
                          energy_shopfloor_hourly[shopfloor_id][current_datetime_utc][energy_item_id] = actual_value
          except Exception as e:
              error_string = "Error in step 16 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 17: for each store in list, get energy input data from energy database
      ####################################################################################################################
      energy_store_hourly = dict()
      if store_list is not None and len(store_list) > 0:
          try:
              for store in store_list:
                  store_id = str(store['id'])
  
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_store_input_item_hourly "
                           " WHERE store_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (store_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_store_hourly[store_id] = None
                  else:
                      energy_store_hourly[store_id] = dict()
                      for row_energy_value in rows_energy_values:
                          current_datetime_utc = row_energy_value[0]
                          if current_datetime_utc not in energy_store_hourly[store_id]:
                              energy_store_hourly[store_id][current_datetime_utc] = dict()
                          energy_item_id = row_energy_value[1]
                          actual_value = row_energy_value[2]
                          energy_store_hourly[store_id][current_datetime_utc][energy_item_id] = actual_value
          except Exception as e:
              error_string = "Error in step 17 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 18: for each tenant in list, get energy input data from energy database
      ####################################################################################################################
      energy_tenant_hourly = dict()
      if tenant_list is not None and len(tenant_list) > 0:
          try:
              for tenant in tenant_list:
                  tenant_id = str(tenant['id'])
  
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_tenant_input_item_hourly "
                           " WHERE tenant_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (tenant_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_tenant_hourly[tenant_id] = None
                  else:
                      energy_tenant_hourly[tenant_id] = dict()
                      for row_energy_value in rows_energy_values:
                          current_datetime_utc = row_energy_value[0]
                          if current_datetime_utc not in energy_tenant_hourly[tenant_id]:
                              energy_tenant_hourly[tenant_id][current_datetime_utc] = dict()
                          energy_item_id = row_energy_value[1]
                          actual_value = row_energy_value[2]
                          energy_tenant_hourly[tenant_id][current_datetime_utc][energy_item_id] = actual_value
          except Exception as e:
              error_string = "Error in step 18 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 19: for each child space in list, get energy input data from energy database
      ####################################################################################################################
      energy_child_space_hourly = dict()
      if child_space_list is not None and len(child_space_list) > 0:
          try:
              for child_space in child_space_list:
                  child_space_id = str(child_space['id'])
  
                  query = (" SELECT start_datetime_utc, energy_item_id, actual_value "
                           " FROM tbl_space_input_item_hourly "
                           " WHERE space_id = %s "
                           "       AND start_datetime_utc >= %s "
                           "       AND start_datetime_utc < %s "
                           " ORDER BY start_datetime_utc ")
                  cursor_energy_db.execute(query, (child_space_id, start_datetime_utc, end_datetime_utc,))
                  rows_energy_values = cursor_energy_db.fetchall()
                  if rows_energy_values is None or len(rows_energy_values) == 0:
                      energy_child_space_hourly[child_space_id] = None
                  else:
                      energy_child_space_hourly[child_space_id] = dict()
                      for row_energy_value in rows_energy_values:
                          current_datetime_utc = row_energy_value[0]
                          if current_datetime_utc not in energy_child_space_hourly[child_space_id]:
                              energy_child_space_hourly[child_space_id][current_datetime_utc] = dict()
                          energy_item_id = row_energy_value[1]
                          actual_value = row_energy_value[2]
                          energy_child_space_hourly[child_space_id][current_datetime_utc][energy_item_id] = actual_value
          except Exception as e:
              error_string = "Error in step 19 of space_energy_input_item.worker " + str(e)
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
              print(error_string)
              return error_string
  
      ####################################################################################################################
      # Step 20: determine common time slot to aggregate
      ####################################################################################################################
  
      common_start_datetime_utc = start_datetime_utc
      common_end_datetime_utc = end_datetime_utc
  
      print("Getting common time slot of energy values for all meters")
      if energy_meter_hourly is not None and len(energy_meter_hourly) > 0:
          for meter_id, energy_hourly in energy_meter_hourly.items():
              if energy_hourly is None or len(energy_hourly) == 0:
                  common_start_datetime_utc = None
                  common_end_datetime_utc = None
                  break
              else:
                  if common_start_datetime_utc < min(energy_hourly.keys()):
                      common_start_datetime_utc = min(energy_hourly.keys())
                  if common_end_datetime_utc > max(energy_hourly.keys()):
                      common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all virtual meters")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_virtual_meter_hourly is not None and len(energy_virtual_meter_hourly) > 0:
              for meter_id, energy_hourly in energy_virtual_meter_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all offline meters")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_offline_meter_hourly is not None and len(energy_offline_meter_hourly) > 0:
              for meter_id, energy_hourly in energy_offline_meter_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all combined equipments")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_combined_equipment_hourly is not None and len(energy_combined_equipment_hourly) > 0:
              for combined_equipment_id, energy_hourly in energy_combined_equipment_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all equipments")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_equipment_hourly is not None and len(energy_equipment_hourly) > 0:
              for equipment_id, energy_hourly in energy_equipment_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all shopfloors")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_shopfloor_hourly is not None and len(energy_shopfloor_hourly) > 0:
              for shopfloor_id, energy_hourly in energy_shopfloor_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all stores")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_store_hourly is not None and len(energy_store_hourly) > 0:
              for store_id, energy_hourly in energy_store_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all tenants")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_tenant_hourly is not None and len(energy_tenant_hourly) > 0:
              for tenant_id, energy_hourly in energy_tenant_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      print("Getting common time slot of energy values for all child spaces")
      if common_start_datetime_utc is not None and common_start_datetime_utc is not None:
          if energy_child_space_hourly is not None and len(energy_child_space_hourly) > 0:
              for child_space_id, energy_hourly in energy_child_space_hourly.items():
                  if energy_hourly is None or len(energy_hourly) == 0:
                      common_start_datetime_utc = None
                      common_end_datetime_utc = None
                      break
                  else:
                      if common_start_datetime_utc < min(energy_hourly.keys()):
                          common_start_datetime_utc = min(energy_hourly.keys())
                      if common_end_datetime_utc > max(energy_hourly.keys()):
                          common_end_datetime_utc = max(energy_hourly.keys())
  
      if (energy_meter_hourly is None or len(energy_meter_hourly) == 0) and \
              (energy_virtual_meter_hourly is None or len(energy_virtual_meter_hourly) == 0) and \
              (energy_offline_meter_hourly is None or len(energy_offline_meter_hourly) == 0) and \
              (energy_combined_equipment_hourly is None or len(energy_combined_equipment_hourly) == 0) and \
              (energy_equipment_hourly is None or len(energy_equipment_hourly) == 0) and \
              (energy_shopfloor_hourly is None or len(energy_shopfloor_hourly) == 0) and \
              (energy_store_hourly is None or len(energy_store_hourly) == 0) and \
              (energy_tenant_hourly is None or len(energy_tenant_hourly) == 0) and \
              (energy_child_space_hourly is None or len(energy_child_space_hourly) == 0):
          # There isn't any energy data
          print("There isn't any energy data")
          # continue the for space loop to the next space
          print("continue the for space loop to the next space")
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
          return None
  
      print("common_start_datetime_utc: " + str(common_start_datetime_utc))
      print("common_end_datetime_utc: " + str(common_end_datetime_utc))
  
      ####################################################################################################################
      # Step 21: aggregate energy data in the common time slot by energy items and hourly
      ####################################################################################################################
  
      print("Step 21: aggregate energy data in the common time slot by energy items and hourly")
      aggregated_values = list()
      try:
          current_datetime_utc = common_start_datetime_utc
          while common_start_datetime_utc is not None \
                  and common_end_datetime_utc is not None \
                  and current_datetime_utc <= common_end_datetime_utc:
              aggregated_value = dict()
              aggregated_value['start_datetime_utc'] = current_datetime_utc
              aggregated_value['meta_data'] = dict()
  
              if meter_list is not None and len(meter_list) > 0:
                  for meter in meter_list:
                      meter_id = str(meter['id'])
                      energy_item_id = meter['energy_item_id']
                      actual_value = energy_meter_hourly[meter_id].get(current_datetime_utc, Decimal(0.0))
                      aggregated_value['meta_data'][energy_item_id] = \
                          aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if virtual_meter_list is not None and len(virtual_meter_list) > 0:
                  for virtual_meter in virtual_meter_list:
                      virtual_meter_id = str(virtual_meter['id'])
                      energy_item_id = virtual_meter['energy_item_id']
                      actual_value = energy_virtual_meter_hourly[virtual_meter_id].get(current_datetime_utc, Decimal(0.0))
                      aggregated_value['meta_data'][energy_item_id] = \
                          aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if offline_meter_list is not None and len(offline_meter_list) > 0:
                  for offline_meter in offline_meter_list:
                      offline_meter_id = str(offline_meter['id'])
                      energy_item_id = offline_meter['energy_item_id']
                      actual_value = energy_offline_meter_hourly[offline_meter_id].get(current_datetime_utc, Decimal(0.0))
                      aggregated_value['meta_data'][energy_item_id] = \
                          aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if combined_equipment_list is not None and len(combined_equipment_list) > 0:
                  for combined_equipment in combined_equipment_list:
                      combined_equipment_id = str(combined_equipment['id'])
                      meta_data_dict = \
                          energy_combined_equipment_hourly[combined_equipment_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if equipment_list is not None and len(equipment_list) > 0:
                  for equipment in equipment_list:
                      equipment_id = str(equipment['id'])
                      meta_data_dict = energy_equipment_hourly[equipment_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if shopfloor_list is not None and len(shopfloor_list) > 0:
                  for shopfloor in shopfloor_list:
                      shopfloor_id = str(shopfloor['id'])
                      meta_data_dict = energy_store_hourly[shopfloor_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if store_list is not None and len(store_list) > 0:
                  for store in store_list:
                      store_id = str(store['id'])
                      meta_data_dict = energy_store_hourly[store_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if tenant_list is not None and len(tenant_list) > 0:
                  for tenant in tenant_list:
                      tenant_id = str(tenant['id'])
                      meta_data_dict = energy_tenant_hourly[tenant_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              if child_space_list is not None and len(child_space_list) > 0:
                  for child_space in child_space_list:
                      child_space_id = str(child_space['id'])
                      meta_data_dict = energy_child_space_hourly[child_space_id].get(current_datetime_utc, None)
                      if meta_data_dict is not None and len(meta_data_dict) > 0:
                          for energy_item_id, actual_value in meta_data_dict.items():
                              aggregated_value['meta_data'][energy_item_id] = \
                                  aggregated_value['meta_data'].get(energy_item_id, Decimal(0.0)) + actual_value
  
              aggregated_values.append(aggregated_value)
  
              current_datetime_utc += timedelta(minutes=config.minutes_to_count)
  
      except Exception as e:
          error_string = "Error in step 19 of space_energy_input_item.worker " + str(e)
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
          print(error_string)
          return error_string
  
      ####################################################################################################################
      # Step 22: save energy data to energy database
      ####################################################################################################################
      print("Step 22: save energy data to energy database")
  
      if len(aggregated_values) > 0:
          try:
              add_values = (" INSERT INTO tbl_space_input_item_hourly "
                            "             (space_id, "
                            "              energy_item_id, "
                            "              start_datetime_utc, "
                            "              actual_value) "
                            " VALUES  ")
  
              for aggregated_value in aggregated_values:
                  for energy_item_id, actual_value in aggregated_value['meta_data'].items():
                      add_values += " (" + str(space['id']) + ","
                      add_values += " " + str(energy_item_id) + ","
                      add_values += "'" + aggregated_value['start_datetime_utc'].isoformat()[0:19] + "',"
                      add_values += str(actual_value) + "), "
              print("add_values:" + add_values)
              # trim ", " at the end of string and then execute
              cursor_energy_db.execute(add_values[:-2])
              cnx_energy_db.commit()
  
          except Exception as e:
              error_string = "Error in step 20 of space_energy_input_item.worker " + str(e)
              print(error_string)
              return error_string
          finally:
              if cursor_energy_db:
                  cursor_energy_db.close()
              if cnx_energy_db:
                  cnx_energy_db.close()
      else:
          if cursor_energy_db:
              cursor_energy_db.close()
          if cnx_energy_db:
              cnx_energy_db.close()
  