"""
Mixin class that provides authoring capabilities for XBlocks.
"""


import logging

from django.conf import settings
from web_fragments.fragment import Fragment
from xblock.core import XBlock, XBlockMixin
from xblock.fields import String, Scope


log = logging.getLogger(__name__)

VISIBILITY_VIEW = 'visibility_view'


@XBlock.needs("i18n")
@XBlock.needs("mako")
class AuthoringMixin(XBlockMixin):
    """
    Mixin class that provides authoring capabilities for XBlocks.
    """

    def _get_studio_resource_url(self, relative_url):
        """
        Returns the Studio URL to a static resource.
        """
        return settings.STATIC_URL + relative_url

    def visibility_view(self, _context=None):
        """
        Render the view to manage an xblock's visibility settings in Studio.
        Args:
            _context: Not actively used for this view.
        Returns:
            (Fragment): An HTML fragment for editing the visibility of this XBlock.
        """
        fragment = Fragment()
        from cms.djangoapps.contentstore.utils import reverse_course_url
        fragment.add_content(self.runtime.service(self, 'mako').render_cms_template('visibility_editor.html', {
            'xblock': self,
            'manage_groups_url': reverse_course_url('group_configurations_list_handler', self.location.course_key),
        }))
        fragment.add_javascript_url(self._get_studio_resource_url('/js/xblock/authoring.js'))
        fragment.initialize_js('VisibilityEditorInit')
        return fragment

    copied_from_block = String(
        # Note: used by the content_staging app. This field is not needed in the LMS.
        help="ID of the block that this one was copied from, if any. Used when copying and pasting blocks in Studio.",
        scope=Scope.settings,
        enforce_type=True,
    )

    def editor_saved(self, user, old_metadata, old_content) -> None:  # pylint: disable=unused-argument
        """
        Called right *before* the block is written to the DB. Can be used, e.g., to modify fields before saving.

        By default, is a no-op. Can be overriden in subclasses.
        """

    def post_editor_saved(self, user, old_metadata, old_content) -> None:  # pylint: disable=unused-argument
        """
        Called right *after* the block is written to the DB. Can be used, e.g., to spin up followup tasks.

        By default, is a no-op. Can be overriden in subclasses.
        """