from flask import Flask

from .config import config
from .db import initialize as initialize_db
from .views import api


def create(config_obj=None):
    """
    Create an instance of the Flask application.

    This pattern of creating the application within a function and registering
    blueprints makes writing tests easier since you can create several
    application objects with different configurations.

    Args:
        config_obj (object): A module or object with configuration options
            attached to it. See the `Flask configuration documentation`_ for
            usage details.

    Returns:
        flask.Flask: The configured Flask application.

    .. _Flask configuration documentation:
        http://flask.pocoo.org/docs/latest/api/#flask.Config.from_object
    """
    app = Flask(__name__)
    if config_obj:
        app.config.from_object(config_obj)
    else:
        app.config.update(config.load_config())
    initialize_db(app.config)

    app.register_blueprint(api.api_blueprint, url_prefix="/api/v1")
    return app