summer_course_2024/hub/persistence/repositories/city.py
2024-05-24 11:19:43 +02:00

142 lines
4.7 KiB
Python

"""
City repository with database CRUD operations
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2022 Concordia CERC group
Project Coder Peter Yefi peteryefi@gmail.com
"""
import datetime
import logging
from sqlalchemy import select
from sqlalchemy.exc import SQLAlchemyError
from sqlalchemy.orm import Session
from hub.city_model_structure.city import City as CityHub
from hub.persistence.repository import Repository
from hub.persistence.models import City as Model
from hub.persistence.models import CityObject
from hub.version import __version__
class City(Repository):
"""
City repository
"""
_instance = None
def __init__(self, db_name: str, dotenv_path: str, app_env: str):
super().__init__(db_name, dotenv_path, app_env)
def __new__(cls, db_name, dotenv_path, app_env):
"""
Implemented for a singleton pattern
"""
if cls._instance is None:
cls._instance = super(City, cls).__new__(cls)
return cls._instance
def insert(self, city: CityHub, pickle_path, scenario, application_id, user_id: int):
"""
Inserts a city
:param city: The complete city instance
:param pickle_path: Path to the pickle
:param scenario: Simulation scenario name
:param application_id: Application id owning the instance
:param user_id: User id owning the instance
:return: Identity id
"""
city.save_compressed(pickle_path)
try:
db_city = Model(
pickle_path,
city.name,
scenario,
application_id,
user_id,
__version__)
with Session(self.engine) as session:
session.add(db_city)
session.flush()
session.commit()
for building in city.buildings:
db_city_object = CityObject(db_city.id,
building)
session.add(db_city_object)
session.flush()
session.commit()
session.refresh(db_city)
return db_city.id
except SQLAlchemyError as err:
logging.error('An error occurred while creating a city %s', err)
raise SQLAlchemyError from err
def update(self, city_id: int, city: CityHub):
"""
Updates a city name (other updates makes no sense)
:param city_id: the id of the city to be updated
:param city: the city object
:return: None
"""
try:
now = datetime.datetime.utcnow()
with Session(self.engine) as session:
session.query(Model).filter(Model.id == city_id).update({'name': city.name, 'updated': now})
session.commit()
except SQLAlchemyError as err:
logging.error('Error while updating city %s', err)
raise SQLAlchemyError from err
def delete(self, city_id: int):
"""
Deletes a City with the id
:param city_id: the city id
:return: None
"""
try:
with Session(self.engine) as session:
session.query(CityObject).filter(CityObject.city_id == city_id).delete()
session.query(Model).filter(Model.id == city_id).delete()
session.commit()
except SQLAlchemyError as err:
logging.error('Error while fetching city %s', err)
raise SQLAlchemyError from err
def get_by_user_id_application_id_and_scenario(self, user_id, application_id, scenario) -> [Model]:
"""
Fetch city based on the user who created it
:param user_id: the user id
:param application_id: the application id
:param scenario: simulation scenario name
:return: [ModelCity]
"""
try:
with Session(self.engine) as session:
result_set = session.execute(select(Model).where(Model.user_id == user_id,
Model.application_id == application_id,
Model.scenario == scenario
)).all()
return result_set
except SQLAlchemyError as err:
logging.error('Error while fetching city by name %s', err)
raise SQLAlchemyError from err
def get_by_user_id_and_application_id(self, user_id, application_id) -> [Model]:
"""
Fetch city based on the user who created it
:param user_id: the user id
:param application_id: the application id
:return: ModelCity
"""
try:
with Session(self.engine) as session:
result_set = session.execute(
select(Model).where(Model.user_id == user_id, Model.application_id == application_id)
)
return [r[0] for r in result_set]
except SQLAlchemyError as err:
logging.error('Error while fetching city by name %s', err)
raise SQLAlchemyError from err
def get_by_id(self, city_id) -> Model:
with Session(self.engine) as session:
return session.execute(select(Model).where(Model.id == city_id)).first()[0]