Add main app stub

import json

import secrets

import base64

from pathlib import Path

from flask import Flask

from flask_apscheduler import APScheduler

from flask_sqlalchemy import SQLAlchemy

from .db_config import get_database_uri, get_uri_for_sqlite

db = SQLAlchemy()

scheduler = APScheduler()

from .model import *

def create_app(test_db_path: Path = None) -> Flask:

    """

    Create the Flask application.

    This will also attempt to connect to a database, either a remote database or a local SQLite database.

    When a test database path is provided, the application will automatically switch into testing mode. This means:

    - The scheduler will not be initialized. No jobs will be run.

    - The test database will be used, no matter what deviating configuration may be specified.

    :param test_db_path: A path to the database used for unit testing purposes

    :return: the Flask application object

    """

    app = Flask(__name__)

    app.logger.info("App instance was successfully created.")

    instance_path = Path(app.instance_path)

    instance_path.mkdir(exist_ok=True)

    sqlalchemy_database_uri = (

        get_uri_for_sqlite(test_db_path)

        if test_db_path

        else get_database_uri(instance_path)

    )

    _connect_db(app, sqlalchemy_database_uri)

    _load_flask_config(app)

    _register_blueprints(app)

    if test_db_path is None:

        # Only start scheduler when we are not in testing mode

        _init_scheduler(app)

    return app

def _load_flask_config(app: Flask) -> None:

    """

    Load the flask specific configuration from the database.

    This will also ensure a SECRET_KEY is set, creating one randomly if necessary.

    """

    with app.app_context():

        for entry in FlaskConfigEntry.query.all():

            entry.apply(app)

        if not app.config["SECRET_KEY"]:

            secret_key_entry = FlaskConfigEntry(

                key="SECRET_KEY", value=secrets.token_hex()

            )

            secret_key_entry.apply(app)

            db.session.add(secret_key_entry)

            db.session.commit()

    if not app.config["SECRET_KEY"]:

        raise Exception(

            "app.config['SECRET_KEY'] should have been set, but wasn't. Aborting!"

        )

def _init_scheduler(app: Flask) -> None:

    """

    Initialize the scheduler (which will add all jobs defined in jobs.py)

    """

    from . import jobs

    scheduler.init_app(app)

    scheduler.start()

def _register_blueprints(app: Flask) -> None:

    """

    Register all blueprints

    """

    from . import main, api

    app.register_blueprint(main.bp)

    app.register_blueprint(api.bp)

def _connect_db(app: Flask, sqlalchemy_database_uri: str) -> None:

    """

    Connect to the database using the given URI and create all database tables if they don't yet exist.

    """

    app.config["SQLALCHEMY_DATABASE_URI"] = sqlalchemy_database_uri

    db.init_app(app)