config.py

import os
from utils.debug_utils import DebugUtils

# This should match exactly the name of the app you specified
APP_NAME = "MY_APP_NAME_HERE"
# default mode is "dev" if environment variable doesn't have an assigned value
DEFAULT_MODE = "dev"
ENV = os.environ.get('ENV', DEFAULT_MODE).lower()
DEBUG_MODE = ENV != 'prod'
URL_PREFIX = f"/{APP_NAME}" if not DEBUG_MODE else ""


class AppDBConfig:

    def __init__(self, bind_key_name, debug_env_var_key, prod_env_var_key, force_prod_con_str=None,
                 force_debug_con_str=None):
        self.bind_key_name = bind_key_name
        self.debug_env_var_key = debug_env_var_key
        self.prod_env_var_key = prod_env_var_key
        self.force_prod_con_str = force_prod_con_str
        self.force_debug_con_str = force_debug_con_str

    # Factory Methods
    @classmethod
    def construct_with_sqllite_debug_db(cls, bind_key_name, sqllite_path, prod_env_var_key, force_prod_con_str=None):
        return AppDBConfig(bind_key_name, None, prod_env_var_key,
                           force_prod_con_str, force_debug_con_str="sqlite:///database{0}.db".format(sqllite_path))
    # End Factory Methods.

    def get_debug_con_str(self):
        return self._get_con_str(self.debug_env_var_key, self.force_debug_con_str)

    # If you have created a database for this app, the connection string will be automatically
    # accessible through the DATABASE_URL environment variable.
    def get_prod_con_str(self):
        return self._get_con_str(self.prod_env_var_key, self.force_prod_con_str)


    # Private Methods
    def _print_warning(self, msg, env_key):
        DebugUtils.print_warning(msg, tag=f"{env_key} - {self.bind_key_name}", tag_wrapper_pair="[]")

    def _get_con_str(self, env_key, force_value):
        if force_value:
            url = force_value
            if url.startswith("sqlite"):
                self._print_warning(f"You are using an sqlite db, you will not be able to perform "
                                    f"migrations on this db!", env_key)
            else:
                # Print warning if not using a hardcoded sqlite connection string
                self._print_warning(f"Hardcoded connection string! Assign it to an environment variable!",
                                    env_key)
        else:
            url = os.environ.get(env_key)
        if url is None:
            self._print_warning("Could not connect to the given database URL!", env_key)
        elif url.startswith("postgres://"):
            # For PostgreSQL databases, the conn string needs to start with "postgresql"
            url = url.replace("postgres://", "postgresql://", 1)
        return url


# ============= DB Configs =============
# ===== DB Bindings =====
# Bindings are referenced by "models" to assign the model to the correct db
FIRST_DB_BIND_NAME = "first_db"
# Add more bindings here
# ...
# ===== End DB Bindings =====
PROD_BINDINGS = dict()
DEV_BINDINGS = dict()
db_configs = [
    # Add more DBs here!
    AppDBConfig(bind_key_name=FIRST_DB_BIND_NAME,
                debug_env_var_key="FIRST_DB_DEBUG_CON_STR",
                prod_env_var_key="FIRST_DB_CON_STR")
    ]
for db_config in db_configs:
    PROD_BINDINGS[db_config.bind_key_name] = db_config.get_prod_con_str()
    DEV_BINDINGS[db_config.bind_key_name] = db_config.get_debug_con_str()

# ============= End DB Configs =============

# Get the static URL of the app (to get around the production path issue)
def get_static_url():
    if DEBUG_MODE:
        return '/static'
    return f'/{APP_NAME}/static'

# Get the app configuration based on the ENV environment variable (default is prod)
def get_app_config():
    if DEBUG_MODE:
        return DevelopmentConfig()
    return ProductionConfig()


class Config(object):
    DEBUG = False
    TESTING = False
    SQLALCHEMY_TRACK_MODIFICATIONS = False
    SQLALCHEMY_BINDS = {}


# Flask App settings for production environment
class ProductionConfig(Config):
    PREFERRED_URL_SCHEME = 'https'
    DEBUG = False
    APPLICATION_ROOT = f"/{APP_NAME}"
    # Source: https://flask-sqlalchemy.palletsprojects.com/en/2.x/binds/
    SQLALCHEMY_BINDS = PROD_BINDINGS


# Flask App settings for local development environment
class DevelopmentConfig(Config):
    DEBUG = True
    SQLALCHEMY_BINDS = DEV_BINDINGS