myems / myems-aggregation

# NOTE: returns None or the error string because that the logger object cannot be passed in as parameter

########################################################################################################################

def worker(equipment):

    ####################################################################################################################

    # Step 1: get all input meters associated with the equipment

    ####################################################################################################################

    print("Step 1: get all input meters associated with the equipment " + str(equipment['name']))

    meter_list = list()

    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 equipment_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

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_meters m, tbl_equipments_meters em "

                                 " WHERE m.id = em.meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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 equipment_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 equipment

    ####################################################################################################################

    print("Step 2: get all input virtual meters associated with the equipment")

    virtual_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_virtual_meters m, tbl_equipments_virtual_meters em "

                                 " WHERE m.id = em.virtual_meter_id "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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 2.1 of equipment_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 equipment

    ####################################################################################################################

    print("Step 3: get all input offline meters associated with the equipment")

    offline_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_offline_meters m, tbl_equipments_offline_meters em "

                                 " WHERE m.id = em.offline_meter_id "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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 3.1 of equipment_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()

    ####################################################################################################################

    # stop to the next equipment if this equipment is empty

    ####################################################################################################################

    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):

        print("This is an empty equipment ")

        return None

    ####################################################################################################################

    # Step 4: determine start datetime and end datetime to aggregate

    ####################################################################################################################

    print("Step 4: 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 4.1 of equipment_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_equipment_input_item_hourly "

                 " WHERE equipment_id = %s ")

        cursor_energy_db.execute(query, (equipment['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 4.2 of equipment_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 5: 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 5.1 of equipment_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 6: 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 6.1 of equipment_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 7: 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 7.1 of equipment_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 8: 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())

    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):

        # There isn't any energy data

        print("There isn't any energy data")

        # continue the for equipment loop to the next equipment

        print("continue the for equipment loop to the next equipment")

        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 9: aggregate energy data in the common time slot by energy items and hourly

    ####################################################################################################################

    print("Step 9: 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

            aggregated_values.append(aggregated_value)

            current_datetime_utc += timedelta(minutes=config.minutes_to_count)

    except Exception as e:

        error_string = "Error in step 9 of equipment_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 10: save energy data to energy database

    ####################################################################################################################

    print("Step 10: save energy data to energy database")

    if len(aggregated_values) > 0:

        try:

            add_values = (" INSERT INTO tbl_equipment_input_item_hourly "

                          "             (equipment_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(equipment['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 10.1 of equipment_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()

# NOTE: returns None or the error string because that the logger object cannot be passed in as parameter

########################################################################################################################

def worker(equipment):

    ####################################################################################################################

    # Step 1: get all output meters associated with the equipment

    ####################################################################################################################

    print("Step 1: get all output meters associated with the equipment " + str(equipment['name']))

    meter_list = list()

    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 equipment_energy_output_category.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

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_meters m, tbl_equipments_meters em "

                                 " WHERE m.id = em.meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = true "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 1.2 of equipment_energy_output_category.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 output virtual meters associated with the equipment

    ####################################################################################################################

    print("Step 2: get all output virtual meters associated with the equipment")

    virtual_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_virtual_meters m, tbl_equipments_virtual_meters em "

                                 " WHERE m.id = em.virtual_meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = true "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 2.1 of equipment_energy_output_category.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 output offline meters associated with the equipment

    ####################################################################################################################

    print("Step 3: get all output offline meters associated with the equipment")

    offline_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_offline_meters m, tbl_equipments_offline_meters em "

                                 " WHERE m.id = em.offline_meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = true "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 3.1 of equipment_energy_output_category.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()

    ####################################################################################################################

    # stop to the next equipment if this equipment is empty

    ####################################################################################################################

    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):

        print("This is an empty equipment ")

        return None

    ####################################################################################################################

    # Step 4: determine start datetime and end datetime to aggregate

    ####################################################################################################################

    print("Step 4: 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 4.1 of equipment_energy_output_category.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_equipment_output_category_hourly "

                 " WHERE equipment_id = %s ")

        cursor_energy_db.execute(query, (equipment['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 4.2 of equipment_energy_output_category.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 5: for each meter in list, get energy output 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 5.1 of equipment_energy_output_category.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 6: for each virtual meter in list, get energy output 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 6.1 of equipment_energy_output_category.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 7: for each offline meter in list, get energy output 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 7.1 of equipment_energy_output_category.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 8: 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())

    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):

        # There isn't any energy data

        print("There isn't any energy data")

        # continue the for equipment loop to the next equipment

        print("continue the for equipment loop to the next equipment")

        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 9: aggregate energy data in the common time slot by energy categories and hourly

    ####################################################################################################################

    print("Step 9: aggregate energy data in the common time slot by energy categories 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_category_id = meter['energy_category_id']

                    actual_value = energy_meter_hourly[meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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_category_id = virtual_meter['energy_category_id']

                    actual_value = energy_virtual_meter_hourly[virtual_meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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_category_id = offline_meter['energy_category_id']

                    actual_value = energy_offline_meter_hourly[offline_meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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 9 of equipment_energy_output_category.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 10: save energy data to energy database

    ####################################################################################################################

    print("Step 10: save energy data to energy database")

    if len(aggregated_values) > 0:

        try:

            add_values = (" INSERT INTO tbl_equipment_output_category_hourly "

                          "             (equipment_id, "

                          "              energy_category_id, "

                          "              start_datetime_utc, "

                          "              actual_value) "

                          " VALUES  ")

            for aggregated_value in aggregated_values:

                for energy_category_id, actual_value in aggregated_value['meta_data'].items():

                    add_values += " (" + str(equipment['id']) + ","

                    add_values += " " + str(energy_category_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 10.1 of equipment_energy_output_category.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()

# NOTE: returns None or the error string because that the logger object cannot be passed in as parameter

########################################################################################################################

def worker(equipment):

    ####################################################################################################################

    # Step 1: get all input meters associated with the equipment

    ####################################################################################################################

    print("Step 1: get all input meters associated with the equipment " + str(equipment['name']))

    meter_list = list()

    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 equipment_energy_input_category.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

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_meters m, tbl_equipments_meters em "

                                 " WHERE m.id = em.meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 1.2 of equipment_energy_input_category.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 equipment

    ####################################################################################################################

    print("Step 2: get all input virtual meters associated with the equipment")

    virtual_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_virtual_meters m, tbl_equipments_virtual_meters em "

                                 " WHERE m.id = em.virtual_meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 2.1 of equipment_energy_input_category.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 equipment

    ####################################################################################################################

    print("Step 3: get all input offline meters associated with the equipment")

    offline_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_category_id "

                                 " FROM tbl_offline_meters m, tbl_equipments_offline_meters em "

                                 " WHERE m.id = em.offline_meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND em.is_output = false "

                                 "       AND em.equipment_id = %s ",

                                 (equipment['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_category_id": row[2]})

    except Exception as e:

        error_string = "Error in step 3.1 of equipment_energy_input_category.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()

    ####################################################################################################################

    # stop to the next equipment if this equipment is empty

    ####################################################################################################################

    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):

        print("This is an empty equipment ")

        return None

    ####################################################################################################################

    # Step 4: determine start datetime and end datetime to aggregate

    ####################################################################################################################

    print("Step 4: 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 4.1 of equipment_energy_input_category.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_equipment_input_category_hourly "

                 " WHERE equipment_id = %s ")

        cursor_energy_db.execute(query, (equipment['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 4.2 of equipment_energy_input_category.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 5: 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 5.1 of equipment_energy_input_category.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 6: 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 6.1 of equipment_energy_input_category.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 7: 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 7.1 of equipment_energy_input_category.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 8: 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())

    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):

        # There isn't any energy data

        print("There isn't any energy data")

        # continue the for equipment loop to the next equipment

        print("continue the for equipment loop to the next equipment")

        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 9: aggregate energy data in the common time slot by energy categories and hourly

    ####################################################################################################################

    print("Step 9: aggregate energy data in the common time slot by energy categories 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_category_id = meter['energy_category_id']

                    actual_value = energy_meter_hourly[meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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_category_id = virtual_meter['energy_category_id']

                    actual_value = energy_virtual_meter_hourly[virtual_meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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_category_id = offline_meter['energy_category_id']

                    actual_value = energy_offline_meter_hourly[offline_meter_id].get(current_datetime_utc, Decimal(0.0))

                    aggregated_value['meta_data'][energy_category_id] = \

                        aggregated_value['meta_data'].get(energy_category_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 9 of equipment_energy_input_category.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 10: save energy data to energy database

    ####################################################################################################################

    print("Step 10: save energy data to energy database")

    if len(aggregated_values) > 0:

        try:

            add_values = (" INSERT INTO tbl_equipment_input_category_hourly "

                          "             (equipment_id, "

                          "              energy_category_id, "

                          "              start_datetime_utc, "

                          "              actual_value) "

                          " VALUES  ")

            for aggregated_value in aggregated_values:

                for energy_category_id, actual_value in aggregated_value['meta_data'].items():

                    add_values += " (" + str(equipment['id']) + ","

                    add_values += " " + str(energy_category_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 10.1 of equipment_energy_input_category.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()

# NOTE: returns None or the error string because that the logger object cannot be passed in as parameter

########################################################################################################################

def worker(tenant):

    ####################################################################################################################

    # Step 1: get all input meters associated with the tenant

    ####################################################################################################################

    print("Step 1: get all input meters associated with the tenant " + str(tenant['name']))

    meter_list = list()

    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 tenant_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

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_meters m, tbl_tenants_meters tm "

                                 " WHERE m.id = tm.meter_id "

                                 "       AND m.is_counted = true "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND tm.tenant_id = %s ",

                                 (tenant['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 tenant_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 tenant

    ####################################################################################################################

    print("Step 2: get all input virtual meters associated with the tenant")

    virtual_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_virtual_meters m, tbl_tenants_virtual_meters tm "

                                 " WHERE m.id = tm.virtual_meter_id "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND m.is_counted = true "

                                 "       AND tm.tenant_id = %s ",

                                 (tenant['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 2.1 of tenant_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 tenant

    ####################################################################################################################

    print("Step 3: get all input offline meters associated with the tenant")

    offline_meter_list = list()

    try:

        cursor_system_db.execute(" SELECT m.id, m.name, m.energy_item_id "

                                 " FROM tbl_offline_meters m, tbl_tenants_offline_meters tm "

                                 " WHERE m.id = tm.offline_meter_id "

                                 "       AND m.energy_item_id is NOT NULL "

                                 "       AND m.is_counted = true "

                                 "       AND tm.tenant_id = %s ",

                                 (tenant['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 3.1 of tenant_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()

    ####################################################################################################################

    # stop to the next tenant if this tenant is empty

    ####################################################################################################################

    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):

        print("This is an empty tenant ")

        return None

    ####################################################################################################################

    # Step 4: determine start datetime and end datetime to aggregate

    ####################################################################################################################

    print("Step 4: 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 4.1 of tenant_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_tenant_input_item_hourly "

                 " WHERE tenant_id = %s ")

        cursor_energy_db.execute(query, (tenant['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 4.2 of tenant_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 5: 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 5.1 of tenant_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 6: 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 6.1 of tenant_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 7: 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 7.1 of tenant_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 8: 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