feat(people): Add Person and Relationship models

people/migrations/0002_add_relationship_models.py

@@ -0,0 +1,59 @@
+# Generated by Django 2.2.9 on 2020-01-30 15:02
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('people', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Person',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('core_member', models.BooleanField(default=False)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='RelationshipQuestion',
+            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=1023)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='RelationshipQuestionChoice',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('text', models.CharField(max_length=1023)),
+                ('question', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='answers', to='people.RelationshipQuestion')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Relationship',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('source', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='relationships_as_source', to='people.Person')),
+                ('target', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='relationships_as_target', to='people.Person')),
+            ],
+        ),
+        migrations.AddField(
+            model_name='person',
+            name='relationship_targets',
+            field=models.ManyToManyField(related_name='relationship_sources', through='people.Relationship', to='people.Person'),
+        ),
+        migrations.AddConstraint(
+            model_name='relationshipquestionchoice',
+            constraint=models.UniqueConstraint(fields=('question', 'text'), name='unique_question_answer'),
+        ),
+        migrations.AddConstraint(
+            model_name='relationship',
+            constraint=models.UniqueConstraint(fields=('source', 'target'), name='unique_relationship'),
+        ),
+    ]

people/migrations/0003_fix_people_plural.py

@@ -0,0 +1,17 @@
+# Generated by Django 2.2.9 on 2020-02-14 09:45
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('people', '0002_add_relationship_models'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='person',
+            options={'verbose_name_plural': 'people'},
+        ),
+    ]

people/models.py

@@ -1,8 +1,86 @@
 from django.contrib.auth.models import AbstractUser
+from django.db import models
 
 
 class User(AbstractUser):
     """
     Custom user model in case we need to make changes later.
     """
-    pass
+
+
+class Person(models.Model):
+    """
+    A person may be a member of the BRECcIA core team or an external stakeholder.
+    """
+
+    class Meta:
+        verbose_name_plural = 'people'
+
+    #: Name of the person
+    name = models.CharField(max_length=255,
+                            blank=False, null=False)
+
+    #: Is this person a member of the core project team?
+    core_member = models.BooleanField(default=False,
+                                      blank=False, null=False)
+
+    #: People with whom this person has relationship - via intermediate :class:`Relationship` model
+    relationship_targets = models.ManyToManyField('self', related_name='relationship_sources',
+                                                  through='Relationship',
+                                                  through_fields=('source', 'target'),
+                                                  symmetrical=False)
+
+
+class RelationshipQuestion(models.Model):
+    """
+    Question which may be asked about a relationship.
+    """
+    #: 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=1023,
+                            blank=False, null=False)
+
+
+class RelationshipQuestionChoice(models.Model):
+    """
+    Allowed answer to a :class:`RelationshipQuestion`.
+    """
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=['question', 'text'],
+                                    name='unique_question_answer')
+        ]
+
+    #: Question to which this answer belongs
+    question = models.ForeignKey(RelationshipQuestion, related_name='answers',
+                                 on_delete=models.CASCADE,
+                                 blank=False, null=False)
+
+    #: Text of answer
+    text = models.CharField(max_length=1023,
+                            blank=False, null=False)
+
+
+class Relationship(models.Model):
+    """
+    A directional relationship between two people allowing linked questions.
+    """
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(fields=['source', 'target'],
+                                    name='unique_relationship'),
+        ]
+
+    #: Person reporting the relationship
+    source = models.ForeignKey(Person, related_name='relationships_as_source',
+                               on_delete=models.CASCADE,
+                               blank=False, null=False)
+
+    #: Person with whom the relationship is reported
+    target = models.ForeignKey(Person, related_name='relationships_as_target',
+                               on_delete=models.CASCADE,
+                               blank=False, null=False)