"""Resolve per-view marker attributes across function and MethodView routes.

View-tag decorators (``@no_store``, ``@rate_category``) set an attribute on the view they
decorate. For a plain function view that is the object Flask stores in
``view_functions[endpoint]``, so the attribute is found directly. For a class-based
``MethodView`` (the dominant style here: ItemView/ListView), ``view_functions`` holds the
``as_view()`` dispatch closure while the decorator's attribute lives on the class's
``get()``/``post()`` method -- so the marker must be resolved off ``view_class`` for the
request's verb. HEAD is special-cased to fall back to ``get`` because Flask's
``MethodView.dispatch_request`` runs ``get()`` for a HEAD request when no ``head()`` is
defined, so a HEAD must be classified like the GET it actually executes.
"""

from typing import Any

from flask import Flask

_SENTINEL = object()


def resolve_view_marker(
    app: Flask, endpoint: str | None, method: str, attr: str, default: Any = None
) -> Any:
    """Return marker ``attr`` for ``endpoint``/``method``, or ``default`` if unset.

    Checks the endpoint's view function first (function views), then, for MethodView
    routes, the class method for the request verb (mirroring Flask's HEAD->get fallback).
    """
    view = app.view_functions.get(endpoint or '')
    value = getattr(view, attr, _SENTINEL)
    if value is not _SENTINEL:
        return value
    view_class = getattr(view, 'view_class', None)
    if view_class is not None:
        handler = getattr(view_class, method.lower(), None)
        if handler is None and method == 'HEAD':
            handler = getattr(view_class, 'get', None)
        if handler is not None:
            return getattr(handler, attr, default)
    return default