From 4cfee6362d11651a3e74e3dc295b61dc51192c10 Mon Sep 17 00:00:00 2001
From: James Graham <j.graham@software.ac.uk>
Date: Fri, 15 Jan 2021 17:45:55 +0000
Subject: [PATCH] refactor: add person update form fields to initial

---
 people/forms.py         | 19 +++++++++--------
 people/models/person.py | 45 +++++++++++++++++++++++++++++++++++++++++
 people/views/person.py  | 12 +++++++++--
 3 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/people/forms.py b/people/forms.py
index d1495d9..607214f 100644
--- a/people/forms.py
+++ b/people/forms.py
@@ -1,6 +1,4 @@
-"""
-Forms for creating / updating models belonging to the 'people' app.
-"""
+"""Forms for creating / updating models belonging to the 'people' app."""
 
 import typing
 
@@ -28,11 +26,7 @@ class OrganisationForm(forms.ModelForm):
     """Form for creating / updating an instance of :class:`Organisation`."""
     class Meta:
         model = models.Organisation
-        fields = [
-            'name',
-            'latitude',
-            'longitude'
-        ]
+        fields = ['name', 'latitude', 'longitude']
 
 
 class PersonForm(forms.ModelForm):
@@ -59,6 +53,8 @@ class DynamicAnswerSetBase(forms.Form):
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
+        initial = kwargs.get('initial', {})
+
         for question in self.question_model.objects.all():
             field_class = self.field_class
             field_widget = self.field_widget
@@ -67,11 +63,14 @@ class DynamicAnswerSetBase(forms.Form):
                 field_class = forms.ModelMultipleChoiceField
                 field_widget = Select2MultipleWidget
 
+            field_name = f'question_{question.pk}'
+
             field = field_class(label=question,
                                 queryset=question.answers,
                                 widget=field_widget,
-                                required=self.field_required)
-            self.fields['question_{}'.format(question.pk)] = field
+                                required=self.field_required,
+                                initial=initial.get(field_name, None))
+            self.fields[field_name] = field
 
 
 class PersonAnswerSetForm(forms.ModelForm, DynamicAnswerSetBase):
diff --git a/people/models/person.py b/people/models/person.py
index a472f82..d0b8509 100644
--- a/people/models/person.py
+++ b/people/models/person.py
@@ -190,5 +190,50 @@ class PersonAnswerSet(AnswerSet):
     #: Longitude for displaying location on a map
     longitude = models.FloatField(blank=True, null=True)
 
+    def as_dict(self):
+        """Get the answers from this set as a dictionary for use in Form.initial."""
+        exclude_fields = {
+            'id',
+            'timestemp',
+            'replaced_timestamp',
+            'person_id',
+            'question_answers',
+            'themes',
+        }
+
+        def field_value_repr(field):
+            """Get the representation of a field's value as required by Form.initial."""
+            attr_val = getattr(self, field.attname)
+
+            # Relation fields need to return PKs
+            if isinstance(field, models.ManyToManyField):
+                return [obj.pk for obj in attr_val.all()]
+
+            if isinstance(field, models.ForeignKey):
+                return attr_val.pk
+
+            return attr_val
+
+        answers = {
+            field.attname: field_value_repr(field)
+            for field in self._meta.get_fields()
+            if field.attname not in exclude_fields
+        }
+
+        for answer in self.question_answers.all():
+            question = answer.question
+            field_name = f'question_{question.pk}'
+
+            if question.is_multiple_choice:
+                if field_name not in answers:
+                    answers[field_name] = []
+
+                answers[field_name].append(answer.pk)
+
+            else:
+                answers[field_name] = answer.pk
+
+        return answers
+
     def get_absolute_url(self):
         return self.person.get_absolute_url()
diff --git a/people/views/person.py b/people/views/person.py
index 28e26f9..73f2e3b 100644
--- a/people/views/person.py
+++ b/people/views/person.py
@@ -84,9 +84,17 @@ class PersonUpdateView(permissions.UserIsLinkedPersonMixin, UpdateView):
         return context
 
     def get_initial(self) -> typing.Dict[str, typing.Any]:
-        return {
+        try:
+            previous_answers = self.object.current_answers.as_dict()
+
+        except AttributeError:
+            previous_answers = {}
+
+        previous_answers.update({
             'person_id': self.object.id,
-        }
+        })
+
+        return previous_answers
 
     def get_form_kwargs(self) -> typing.Dict[str, typing.Any]:
         """Remove instance from form kwargs as it's a person, but expects a PersonAnswerSet."""