"""Django integration utilities for loading and accessing the content store."""

from importlib import import_module

from django.conf import settings

_CONTENTSTORE = {}


def load_function(path):
    """
    Load a function by name.

    path is a string of the form "path.to.module.function"
    returns the imported python object `function` from `path.to.module`
    """
    module_path, _, name = path.rpartition(".")
    return getattr(import_module(module_path), name)


def contentstore(name="default"):
    """Return a contentstore instance by name, creating and caching it if not already initialized."""
    if name not in _CONTENTSTORE:
        class_ = load_function(settings.CONTENTSTORE["ENGINE"])
        options = {}
        options.update(settings.CONTENTSTORE["DOC_STORE_CONFIG"])
        if "ADDITIONAL_OPTIONS" in settings.CONTENTSTORE:
            if name in settings.CONTENTSTORE["ADDITIONAL_OPTIONS"]:
                options.update(settings.CONTENTSTORE["ADDITIONAL_OPTIONS"][name])
        _CONTENTSTORE[name] = class_(**options)

    return _CONTENTSTORE[name]