from wagtail.admin.edit_handlers import FieldPanel                                             
from wagtail.admin.edit_handlers import MultiFieldPanel     
from wagtail.admin.edit_handlers import ObjectList
from wagtail.contrib.modeladmin.options import ModelAdmin


class DynamicPanelMixin:                                                                    
      def get_edit_handler(self, instance, request):                                             
          return ObjectList(self._get_panels(instance))

      def _get_panels(self, instance):                                                           
          return [                                                                               
              *self._get_head_panels(instance),                                                  
              MultiFieldPanel(                                                                   
                  self._get_multi_panels(instance),                                              
                  heading="Collapsed",                                                           
                  classname="collapsible collapsed",                                             
              ),                                                                                 
          ]                                          
                                                                                                 
      def _get_head_panels(self, instance):                                                      
          panels = [                                                                             
              FieldPanel("foo"),                                                                                                                
          ]                                                                                      
          return panels + getattr(instance, "head_panels", [])                                   
                                                                                                 
      def _get_multi_panels(self, instance):                                                     
          panels = [                                                                             
              FieldPanel("bar"),                                                               
          ]                                                                                      
          return panels + getattr(instance, "multi_panels", [])


# class MyModelAdmin(DynamicPanelMixin, ModelAdmin):
#     pass