"""
WSGI Wrapper Module for Process Orchestration.

This module provides a wrapper that allows WSGI applications to be run
via uvicorn by wrapping them with a2wsgi.

The WSGI app path is passed via environment variables:
- PYSERVE_WSGI_APP: The app path (e.g., "myapp:app" or "myapp.main:create_app")
- PYSERVE_WSGI_FACTORY: "1" if the app path points to a factory function
"""

import importlib
import os
from typing import Any, Callable

try:
    from a2wsgi import WSGIMiddleware

    WSGI_ADAPTER = "a2wsgi"
except ImportError:
    try:
        from asgiref.wsgi import WsgiToAsgi as WSGIMiddleware  # type: ignore

        WSGI_ADAPTER = "asgiref"
    except ImportError:
        WSGIMiddleware = None  # type: ignore
        WSGI_ADAPTER = None


def _load_wsgi_app() -> Callable:
    app_path = os.environ.get("PYSERVE_WSGI_APP")
    is_factory = os.environ.get("PYSERVE_WSGI_FACTORY", "0") == "1"

    if not app_path:
        raise RuntimeError("PYSERVE_WSGI_APP environment variable not set. " "This module should only be used by PyServe process orchestration.")

    if ":" in app_path:
        module_name, attr_name = app_path.rsplit(":", 1)
    else:
        module_name = app_path
        attr_name = "app"

    try:
        module = importlib.import_module(module_name)
    except ImportError as e:
        raise RuntimeError(f"Failed to import WSGI module '{module_name}': {e}")

    try:
        app_or_factory = getattr(module, attr_name)
    except AttributeError:
        raise RuntimeError(f"Module '{module_name}' has no attribute '{attr_name}'")

    if is_factory:
        return app_or_factory()
    return app_or_factory


def _create_asgi_app() -> Any:
    if WSGIMiddleware is None:
        raise RuntimeError("No WSGI adapter available. " "Install a2wsgi (recommended) or asgiref: pip install a2wsgi")

    wsgi_app = _load_wsgi_app()
    return WSGIMiddleware(wsgi_app)


app = _create_asgi_app()