city_retrofit/hub/persistence/repositories/application.py

107 lines
3.5 KiB
Python

"""
Application repository with database CRUD operations
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2022 Concordia CERC group
Project Coder Guille Gutierrez Guillermo.GutierrezMorote@concordia.ca
"""
import datetime
import logging
from sqlalchemy import select
from sqlalchemy.exc import SQLAlchemyError
from hub.persistence.repository import Repository
from hub.persistence.models import Application as Model
class Application(Repository):
"""
Application 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(Application, cls).__new__(cls)
return cls._instance
def insert(self, name: str, description: str, application_uuid: str):
"""
Inserts a new application
:param name: Application name
:param description: Application description
:param application_uuid: Unique identifier for the application
:return: Identity id
"""
try:
application = self.get_by_uuid(application_uuid)
if application is not None:
raise SQLAlchemyError('application already exists')
except TypeError:
pass
try:
application = Model(name=name, description=description, application_uuid=application_uuid)
self.session.add(application)
self.session.commit()
self.session.refresh(application)
return application.id
except SQLAlchemyError as err:
logging.error('An error occurred while creating application %s', err)
raise SQLAlchemyError from err
def update(self, application_uuid: str, name: str, description: str):
"""
Updates an application
:param application_uuid: the application uuid of the application to be updated
:param name: the application name
:param description: the application description
:return: None
"""
try:
self.session.query(Model).filter(
Model.application_uuid == application_uuid
).update({'name': name, 'description': description, 'updated': datetime.datetime.utcnow()})
self.session.commit()
except SQLAlchemyError as err:
logging.error('Error while updating application %s', err)
raise SQLAlchemyError from err
def delete(self, application_uuid: str):
"""
Deletes an application with the application_uuid
:param application_uuid: The application uuid
:return: None
"""
try:
self.session.query(Model).filter(Model.application_uuid == application_uuid).delete()
self.session.flush()
self.session.commit()
except SQLAlchemyError as err:
logging.error('Error while deleting application %s', err)
raise SQLAlchemyError from err
def get_by_uuid(self, application_uuid: str) -> Model:
"""
Fetch Application based on the application uuid
:param application_uuid: the application uuid
:return: Application with the provided application_uuid
"""
try:
result_set = self.session.execute(select(Model).where(
Model.application_uuid == application_uuid)
).first()
return result_set[0]
except SQLAlchemyError as err:
logging.error('Error while fetching application by application_uuid %s', err)
raise SQLAlchemyError from err
except TypeError as err:
logging.error('Error while fetching application, empty result %s', err)
raise TypeError from err