app.py

import os

from flask import Flask, jsonify
from flask_smorest import Api
from flask_jwt_extended import JWTManager
from flask_migrate import Migrate
from dotenv import load_dotenv

from blocklist import BLOCKLIST
from db import db

from controllers.item import blp as ItemBlueprint
from controllers.store import blp as StoreBlueprint
from controllers.tag import blp as TagBlueprint
from controllers.user import blp as UserBlueprint

def create_app(db_url=None):
    app = Flask(__name__)
    load_dotenv()

    app.config["PROPAGATE_EXCEPTIONS"] = True
    app.config["API_TITLE"] = "Store Inventory REST API"
    app.config["API_VERSION"] = "v1" 
    app.config["OPENAPI_VERSION"] = "3.0.3" 
    app.config["OPENAPI_URL_PREFIX"] = "/"
    app.config["OPENAPI_SWAGGER_UI_PATH"] = "/swagger-ui" 
    app.config["OPENAPI_SWAGGER_UI_URL"] = "https://cdn.jsdelivr.net/npm/swagger-ui-dist/"
    app.config["SQLALCHEMY_DATABASE_URI"] = db_url or os.getenv("DATABASE_URL", "sqlite:///data.db")
    app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
    
    db.init_app(app)
    migrate = Migrate(app, db)
    api = Api(app)

    # app.config["JWT_SECRET_KEY"] = secrets.SystemRandom().getrandbits(128) 
    app.config["JWT_SECRET_KEY"] = "jose"
    jwt = JWTManager(app)

    @jwt.token_in_blocklist_loader
    def check_if_token_in_blocklist(jwt_header, jwt_payload):
        return jwt_payload['jti'] in BLOCKLIST

    @jwt.revoked_token_loader
    def revoked_token_callback(jwt_header, jwt_payload):
        return (jsonify({"description": "The token has been revoked.", "error": "token_revoked"}), 401)

    @jwt.additional_claims_loader
    def add_claims_to_jwt(identity):
        # Look in the db and see whether the user is admin
        if identity == 1:
            return {"is_admin": True}
        return {"is_admin": False}

    @jwt.expired_token_loader
    def expired_token_callback(jwt_header, jwt_payload):
        return (
            jsonify({"message": "The token has expired.", "error": "token_expired"}),
            401,
        )

    @jwt.invalid_token_loader
    def invalid_token_callback(error):
        return (
            jsonify(
                {"message": "Signature verification failed.", "error": "invalid_token"}
            ),
            401,
        )

    @jwt.unauthorized_loader
    def missing_token_callback(error):
        return (
            jsonify(
                {
                    "description": "Request does not contain an access token!",
                    "error": "authorization_required",
                }
            ),
            401,
        )

    @app.before_first_request
    def create_tables():
        db.create_all()

    api.register_blueprint(ItemBlueprint)
    api.register_blueprint(StoreBlueprint)
    api.register_blueprint(TagBlueprint)
    api.register_blueprint(UserBlueprint)

    return app