from importlib import import_module
import warnings
from django.apps import apps
from django.conf import settings
from django.core import urlresolvers
from django.core.exceptions import ImproperlyConfigured
from django.contrib.comments.models import Comment
from django.contrib.comments.forms import CommentForm

warnings.warn("django.contrib.comments is deprecated and will be removed before Django 1.8.", DeprecationWarning)

DEFAULT_COMMENTS_APP = 'django.contrib.comments'

def get_comment_app():
    """
    Get the comment app (i.e. "django.contrib.comments") as defined in the settings
    """
    try:
        app_config = apps.get_app_config(get_comment_app_name().rpartition(".")[2])
    except LookupError:
        raise ImproperlyConfigured("The COMMENTS_APP (%r) "
                                   "must be in INSTALLED_APPS" % settings.COMMENTS_APP)
    return app_config.module

def get_comment_app_name():
    """
    Returns the name of the comment app (either the setting value, if it
    exists, or the default).
    """
    return getattr(settings, 'COMMENTS_APP', DEFAULT_COMMENTS_APP)

def get_model():
    """
    Returns the comment model class.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_model"):
        return get_comment_app().get_model()
    else:
        return Comment

def get_form():
    """
    Returns the comment ModelForm class.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_form"):
        return get_comment_app().get_form()
    else:
        return CommentForm

def get_form_target():
    """
    Returns the target URL for the comment form submission view.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_form_target"):
        return get_comment_app().get_form_target()
    else:
        return urlresolvers.reverse("django.contrib.comments.views.comments.post_comment")

def get_flag_url(comment):
    """
    Get the URL for the "flag this comment" view.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_flag_url"):
        return get_comment_app().get_flag_url(comment)
    else:
        return urlresolvers.reverse("django.contrib.comments.views.moderation.flag",
                                    args=(comment.id,))

def get_delete_url(comment):
    """
    Get the URL for the "delete this comment" view.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_delete_url"):
        return get_comment_app().get_delete_url(comment)
    else:
        return urlresolvers.reverse("django.contrib.comments.views.moderation.delete",
                                    args=(comment.id,))

def get_approve_url(comment):
    """
    Get the URL for the "approve this comment from moderation" view.
    """
    if get_comment_app_name() != DEFAULT_COMMENTS_APP and hasattr(get_comment_app(), "get_approve_url"):
        return get_comment_app().get_approve_url(comment)
    else:
        return urlresolvers.reverse("django.contrib.comments.views.moderation.approve",
                                    args=(comment.id,))