import os
from flask import Flask
from .extensions import db, migrate
import logging
from logging.handlers import RotatingFileHandler


def create_app(config=None):
    BASE_DIR = os.path.dirname(os.path.abspath(__file__))
    # point templates/static to repository-level folders for compatibility
    project_root = os.path.dirname(BASE_DIR)
    app = Flask(__name__, template_folder=os.path.join(project_root, 'templates'), static_folder=os.path.join(project_root, 'static'), instance_relative_config=True)
    # default config
    DB_PATH = os.path.join(os.path.dirname(BASE_DIR), 'anmeldung.db')
    app.config.setdefault('SQLALCHEMY_DATABASE_URI', f'sqlite:///{DB_PATH}')
    app.config.setdefault('SQLALCHEMY_TRACK_MODIFICATIONS', False)

    if config:
        app.config.update(config)

    # init extensions
    db.init_app(app)
    migrate.init_app(app, db)

    # logging setup (mirror previous behavior)
    LOG_DIR = os.path.join(os.path.dirname(BASE_DIR), 'logs')
    os.makedirs(LOG_DIR, exist_ok=True)
    log_file = os.path.join(LOG_DIR, 'app.log')
    handler = RotatingFileHandler(log_file, maxBytes=5 * 1024 * 1024, backupCount=3)
    formatter = logging.Formatter('%(asctime)s %(levelname)s %(name)s: %(message)s')
    handler.setFormatter(formatter)
    handler.setLevel(logging.INFO)
    app.logger.addHandler(handler)
    app.logger.setLevel(logging.INFO)

    # register blueprints
    from .routes import bp as public_bp
    app.register_blueprint(public_bp)

    # expose BASE_DIR on app for compatibility
    app.BASE_DIR = os.path.dirname(BASE_DIR)

    return app