refactor: migrate to question sets for person qs

This means we're starting to use the same system for person questions
as for relationship questions

people/admin.py

@@ -21,19 +21,34 @@ class OrganisationAdmin(admin.ModelAdmin):
     pass
 
 
-@admin.register(models.Role)
-class RoleAdmin(admin.ModelAdmin):
-    pass
-
-
 @admin.register(models.Theme)
 class ThemeAdmin(admin.ModelAdmin):
     pass
 
 
+class PersonQuestionChoiceInline(admin.TabularInline):
+    model = models.PersonQuestionChoice
+
+
+@admin.register(models.PersonQuestion)
+class PersonQuestionAdmin(admin.ModelAdmin):
+    inlines = [
+        PersonQuestionChoiceInline,
+    ]
+
+
+class PersonAnswerSetInline(admin.TabularInline):
+    model = models.PersonAnswerSet
+    readonly_fields = [
+        'question_answers',
+    ]
+
+
 @admin.register(models.Person)
 class PersonAdmin(admin.ModelAdmin):
-    pass
+    inlines = [
+        PersonAnswerSetInline,
+    ]
 
 
 class RelationshipQuestionChoiceInline(admin.TabularInline):

people/forms.py

@@ -40,7 +40,6 @@ class PersonForm(forms.ModelForm):
             'organisation_started_date',
             'job_title',
             'disciplines',
-            'role',
             'themes',
         ]
         widgets = {

people/migrations/0022_refactor_person_questions.py

@@ -0,0 +1,55 @@
+# Generated by Django 2.2.10 on 2020-11-23 14:29
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('people', '0021_refactor_person_disciplines'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='PersonQuestion',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('version', models.PositiveSmallIntegerField(default=1)),
+                ('text', models.CharField(max_length=255)),
+                ('order', models.SmallIntegerField(default=0)),
+            ],
+            options={
+                'ordering': ['order', 'text'],
+            },
+        ),
+        migrations.CreateModel(
+            name='PersonQuestionChoice',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('text', models.CharField(max_length=255)),
+                ('order', models.SmallIntegerField(default=0)),
+                ('question', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='answers', to='people.PersonQuestion')),
+            ],
+            options={
+                'ordering': ['question__order', 'order', 'text'],
+            },
+        ),
+        migrations.CreateModel(
+            name='PersonAnswerSet',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('timestamp', models.DateTimeField(auto_now_add=True)),
+                ('replaced_timestamp', models.DateTimeField(blank=True, editable=False, null=True)),
+                ('person', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='answer_sets', to='people.Person')),
+                ('question_answers', models.ManyToManyField(to='people.PersonQuestionChoice')),
+            ],
+            options={
+                'ordering': ['timestamp'],
+            },
+        ),
+        migrations.AddConstraint(
+            model_name='personquestionchoice',
+            constraint=models.UniqueConstraint(fields=('question', 'text'), name='unique_question_answer'),
+        ),
+    ]

people/migrations/0023_remove_person_role.py

@@ -0,0 +1,65 @@
+# Generated by Django 2.2.10 on 2020-11-25 15:50
+
+from django.core.exceptions import ObjectDoesNotExist
+from django.db import migrations
+from django.utils import timezone
+
+from .utils.question_sets import port_question
+
+
+def migrate_forward(apps, schema_editor):
+    Person = apps.get_model('people', 'Person')
+    Role = apps.get_model('people', 'Role')
+
+    role_question = port_question(apps, 'Role',
+                                  Role.objects.values_list('name', flat=True))
+
+    for person in Person.objects.all():
+        try:
+            prev_set = person.answer_sets.latest('timestamp')
+
+        except ObjectDoesNotExist:
+            prev_set = None
+
+        try:
+
+            answer_set = person.answer_sets.create()
+            answer_set.question_answers.add(
+                role_question.answers.get(text=person.role.name))
+
+            prev_set.replaced_timestamp = timezone.datetime.now()
+
+        except AttributeError:
+            pass
+
+
+def migrate_backward(apps, schema_editor):
+    Person = apps.get_model('people', 'Person')
+    Role = apps.get_model('people', 'Role')
+
+    for person in Person.objects.all():
+        try:
+            current_answers = person.answer_sets.latest('timestamp')
+            role_answer = current_answers.question_answers.get(
+                question__text='Role')
+            person.role, _ = Role.objects.get_or_create(name=role_answer.text)
+            person.save()
+
+        except ObjectDoesNotExist:
+            pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('people', '0022_refactor_person_questions'),
+    ]
+
+    operations = [
+        migrations.RunPython(migrate_forward, migrate_backward),
+        migrations.RemoveField(
+            model_name='person',
+            name='role',
+        ),
+        migrations.DeleteModel('Role'),
+    ]

people/migrations/utils/question_sets.py

@@ -0,0 +1,23 @@
+
+import typing
+
+from django.core.exceptions import ObjectDoesNotExist
+
+
+def port_question(apps, question_text: str,
+                  answers_text: typing.Iterable[str]):
+    PersonQuestion = apps.get_model('people', 'PersonQuestion')
+
+    try:
+        prev_question = PersonQuestion.objects.filter(
+            text=question_text).latest('version')
+        question = PersonQuestion.objects.create(
+            text=question_text, version=prev_question.version + 1)
+
+    except ObjectDoesNotExist:
+        question = PersonQuestion.objects.create(text=question_text)
+
+    for answer_text in answers_text:
+        question.answers.get_or_create(text=answer_text)
+
+    return question

people/models/person.py

@@ -1,10 +1,12 @@
 import logging
+import typing
 
 from django.conf import settings
 from django.contrib.auth.models import AbstractUser
 from django.core.exceptions import ValidationError
 from django.db import models
 from django.urls import reverse
+from django.utils.text import slugify
 from django.utils.translation import gettext_lazy as _
 
 from django_countries.fields import CountryField
@@ -18,9 +20,11 @@ logger = logging.getLogger(__name__)  # pylint: disable=invalid-name
 __all__ = [
     'User',
     'Organisation',
-    'Role',
     'Theme',
+    'PersonQuestion',
+    'PersonQuestionChoice',
     'Person',
+    'PersonAnswerSet',
 ]
 
 
@@ -36,7 +40,7 @@ class User(AbstractUser):
         """
         return hasattr(self, 'person')
 
-    def send_welcome_email(self):
+    def send_welcome_email(self) -> None:
         """Send a welcome email to a new user."""
         # Get exported data from settings.py first
         context = settings_export(None)
@@ -71,16 +75,6 @@ class Organisation(models.Model):
         return self.name
 
 
-class Role(models.Model):
-    """
-    Role which a :class:`Person` holds within the project.
-    """
-    name = models.CharField(max_length=255, blank=False, null=False)
-
-    def __str__(self) -> str:
-        return self.name
-
-
 class Theme(models.Model):
     """
     Project theme within which a :class:`Person` works.
@@ -91,6 +85,79 @@ class Theme(models.Model):
         return self.name
 
 
+class PersonQuestion(models.Model):
+    """Question which may be asked about a person."""
+    class Meta:
+        ordering = [
+            'order',
+            'text',
+        ]
+
+    #: Version number of this question - to allow modification without invalidating existing data
+    version = models.PositiveSmallIntegerField(default=1,
+                                               blank=False, null=False)
+
+    #: Text of question
+    text = models.CharField(max_length=255,
+                            blank=False, null=False)
+
+    #: Position of this question in the list
+    order = models.SmallIntegerField(default=0,
+                                     blank=False, null=False)
+
+    @property
+    def choices(self) -> typing.List[typing.List[str]]:
+        """
+        Convert the :class:`PersonQuestionChoice`s for this question into Django choices.
+        """
+        return [
+            [choice.pk, str(choice)] for choice in self.answers.all()
+        ]
+
+    @property
+    def slug(self) -> str:
+        return slugify(self.text)
+
+    def __str__(self) -> str:
+        return self.text
+
+
+class PersonQuestionChoice(models.Model):
+    """
+    Allowed answer to a :class:`PersonQuestion`.
+    """
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=['question', 'text'],
+                                    name='unique_question_answer')
+        ]
+        ordering = [
+            'question__order',
+            'order',
+            'text',
+        ]
+
+    #: Question to which this answer belongs
+    question = models.ForeignKey(PersonQuestion, related_name='answers',
+                                 on_delete=models.CASCADE,
+                                 blank=False, null=False)
+
+    #: Text of answer
+    text = models.CharField(max_length=255,
+                            blank=False, null=False)
+
+    #: Position of this answer in the list
+    order = models.SmallIntegerField(default=0,
+                                     blank=False, null=False)
+
+    @property
+    def slug(self) -> str:
+        return slugify(self.text)
+
+    def __str__(self) -> str:
+        return self.text
+
+
 class Person(models.Model):
     """
     A person may be a member of the BRECcIA core team or an external stakeholder.
@@ -168,13 +235,6 @@ class Person(models.Model):
     #: Discipline(s) within which this person works
     disciplines = models.CharField(max_length=255, blank=True, null=True)
 
-    #: Role this person holds within the project
-    role = models.ForeignKey(Role,
-                             on_delete=models.PROTECT,
-                             related_name='holders',
-                             blank=True,
-                             null=True)
-
     #: Project themes within this person works
     themes = models.ManyToManyField(Theme, related_name='people', blank=True)
 
@@ -183,8 +243,42 @@ class Person(models.Model):
         return self.relationships_as_source.all().union(
             self.relationships_as_target.all())
 
+    @property
+    def current_answers(self) -> 'PersonAnswerSet':
+        return self.answer_sets.last()
+
     def get_absolute_url(self):
         return reverse('people:person.detail', kwargs={'pk': self.pk})
 
     def __str__(self) -> str:
         return self.name
+
+
+class PersonAnswerSet(models.Model):
+    """
+    The answers to the person questions at a particular point in time.
+    """
+
+    class Meta:
+        ordering = [
+            'timestamp',
+        ]
+
+    #: Person to which this answer set belongs
+    person = models.ForeignKey(Person,
+                               on_delete=models.CASCADE,
+                               related_name='answer_sets',
+                               blank=False, null=False)
+
+    #: Answers to :class:`PersonQuestion`s
+    question_answers = models.ManyToManyField(PersonQuestionChoice)
+
+    #: When were these answers collected?
+    timestamp = models.DateTimeField(auto_now_add=True,
+                                     editable=False)
+
+    replaced_timestamp = models.DateTimeField(blank=True, null=True,
+                                              editable=False)
+
+    def get_absolute_url(self):
+        return self.person.get_absolute_url()

people/templates/people/person/detail.html

@@ -58,11 +58,6 @@
                 <dd>{{ person.job_title }}</dd>
             {% endif %}
 
-            {% if person.role %}
-                <dt>Role</dt>
-                <dd>{{ person.role }}</dd>
-            {% endif %}
-
             {% if person.disciplines %}
                 <dt>Discipline(s)</dt>
                 <dd>{{ person.disciplines }}</dd>
@@ -79,6 +74,33 @@
         </dl>
     {% endif %}
 
+    {% with person.current_answers as answer_set %}
+        <table class="table table-borderless">
+            <thead>
+            <tr>
+                <th>Question</th>
+                <th>Answer</th>
+            </tr>
+            </thead>
+
+            <tbody>
+            {% for answer in answer_set.question_answers.all %}
+                <tr>
+                    <td>{{ answer.question }}</td>
+                    <td>{{ answer }}</td>
+                </tr>
+
+            {% empty %}
+                <tr>
+                    <td>No records</td>
+                </tr>
+            {% endfor %}
+            </tbody>
+        </table>
+
+        <p>Last updated: {{ answer_set.timestamp }}</p>
+    {% endwith %}
+
     <a class="btn btn-success"
        href="{% url 'people:person.update' pk=person.pk %}">Update</a>