"""Application factory for the Flask server."""
from __future__ import annotations

import logging

from flask import Flask

from . import logging_config, middleware, routes, settings
from .database import init_db, is_postgres_enabled


def _configure_sentry() -> None:
    if not settings.SENTRY_DSN:
        return
    try:
        import sentry_sdk
        from sentry_sdk.integrations.flask import FlaskIntegration

        sentry_sdk.init(
            dsn=settings.SENTRY_DSN,
            integrations=[FlaskIntegration()],
            traces_sample_rate=settings.SENTRY_TRACES_SAMPLE_RATE,
        )
        logging.info("Sentry initialized")
    except Exception:
        logging.exception("Failed to initialize Sentry SDK")


def create_app() -> Flask:
    """Create and configure the Flask application instance."""
    logging_config.configure_logging()

    if settings.POSTGRES_URL:
        try:
            import psycopg2  # type: ignore  # noqa: F401
        except Exception:
            logging.warning(
                "POSTGRES_URL is set but psycopg2 is not installed; falling back to SQLite"
            )

    app = Flask(__name__)
    app.config.from_mapping(SECRET_KEY=settings.SECRET_KEY)
    app.template_folder = str(settings.BASE_DIR / "templates")

    middleware.register_request_hooks(app)
    routes.register_blueprints(app)

    try:
        init_db()
    except Exception:
        logging.exception("Failed to initialize DB at import time")

    is_postgres_enabled()
    _configure_sentry()

    return app