from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_login import LoginManager
from flask_migrate import Migrate
import config

db = SQLAlchemy()
login_manager = LoginManager()
migrate = Migrate()

# Flask-Login configuration
login_manager.login_view = 'auth.login'
login_manager.login_message = 'Please log in to access this page.'


def create_app():
    app = Flask(__name__)
    app.config.from_object(config.Config)

    # Initialize extensions
    db.init_app(app)
    login_manager.init_app(app)
    migrate.init_app(app, db)

    # Initialize model classes with db instance
    from .models import init_db_models
    init_db_models(db)

    # Import model classes (stored on init_db_models function)
    User = init_db_models.User
    UserSettings = init_db_models.UserSettings
    DailyLog = init_db_models.DailyLog
    DailyLogItem = init_db_models.DailyLogItem

    # Flask-Login user loader (must be defined after User class exists)
    @login_manager.user_loader
    def load_user(user_id):
        return User.query.get(int(user_id))

    # Register blueprints
    from . import routes
    app.register_blueprint(routes.bp)

    from . import auth
    app.register_blueprint(auth.auth_bp)

    return app