Move WeightResponse to its own model

Author: Themitchell

lung_cancer_screening/questions/forms/imperial_weight_form.py

@@ -1,15 +1,15 @@
 from django import forms
 
 from ...nhsuk_forms.imperial_weight_field import ImperialWeightField
-from ..models.response_set import ResponseSet
+from ..models.weight_response import WeightResponse
 
 
 class ImperialWeightForm(forms.ModelForm):
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
-        self.fields["weight_imperial"] = ImperialWeightField(
+        self.fields["imperial"] = ImperialWeightField(
             label="Weight",
             required=True,
             require_all_fields=False,
@@ -18,9 +18,9 @@ def __init__(self, *args, **kwargs):
             }
         )
 
-    def clean_weight_metric(self):
+    def clean_metric(self):
         return None
 
     class Meta:
-        model = ResponseSet
-        fields = ['weight_imperial', 'weight_metric']
+        model = WeightResponse
+        fields = ['imperial', 'metric']

lung_cancer_screening/questions/forms/metric_weight_form.py

@@ -1,7 +1,7 @@
 from django import forms
 
 from ...nhsuk_forms.decimal_field import DecimalField
-from ..models.response_set import ResponseSet
+from ..models.weight_response import WeightResponse
 
 
 class MetricWeightForm(forms.ModelForm):
@@ -10,10 +10,10 @@ def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
         # Convert hundreds of grams to kg for display
-        if self.instance and self.instance.weight_metric is not None:
-            self.initial['weight_metric'] = self.instance.weight_metric / 10
+        if self.instance and self.instance.metric is not None:
+            self.initial['metric'] = self.instance.metric / 10
 
-        self.fields["weight_metric"] = DecimalField(
+        self.fields["metric"] = DecimalField(
             decimal_places=1,
             label="Kilograms",
             classes="nhsuk-input--width-4",
@@ -28,12 +28,12 @@ def __init__(self, *args, **kwargs):
             suffix="kg"
         )
 
-    def clean_weight_metric(self):
-        return self.cleaned_data['weight_metric'] * 10
+    def clean_metric(self):
+        return int(self.cleaned_data['metric'] * 10)
 
-    def clean_weight_imperial(self):
+    def clean_imperial(self):
         return None
 
     class Meta:
-        model = ResponseSet
-        fields = ['weight_metric', 'weight_imperial']
+        model = WeightResponse
+        fields = ['metric', 'imperial']

lung_cancer_screening/questions/jinja2/weight.jinja

@@ -43,9 +43,9 @@
         }) %}
 
         {% if unit == "imperial" %}
-          {{ form.weight_imperial.as_field_group() }}
+          {{ form.imperial.as_field_group() }}
         {% else %}
-          {{ form.weight_metric.as_field_group() }}
+          {{ form.metric.as_field_group() }}
         {% endif %}
 
           <p><a href="?unit={{ switch_to_unit }}">Switch to {{ WEIGHT_UNIT[switch_to_unit] }}</a></p>

lung_cancer_screening/questions/migrations/0033_weightresponse.py

@@ -0,0 +1,60 @@
+# Generated manually to create WeightResponse and copy data
+
+import django.core.validators
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+def copy_weight_data(apps, schema_editor):
+    with schema_editor.connection.cursor() as cursor:
+        cursor.execute("""
+            INSERT INTO questions_weightresponse (created_at, updated_at, metric, imperial, response_set_id)
+            SELECT NOW(), NOW(), weight_metric, weight_imperial, id
+            FROM questions_responseset
+            WHERE weight_metric IS NOT NULL OR weight_imperial IS NOT NULL
+            ON CONFLICT (response_set_id) DO NOTHING
+        """)
+
+
+def reverse_copy_weight_data(apps, schema_editor):
+    with schema_editor.connection.cursor() as cursor:
+        cursor.execute("""
+            UPDATE questions_responseset rs
+            SET weight_metric = w.metric,
+                weight_imperial = w.imperial
+            FROM questions_weightresponse w
+            WHERE rs.id = w.response_set_id
+        """)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('questions', '0032_sexatbirthresponse'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='WeightResponse',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+                ('metric', models.PositiveIntegerField(blank=True, null=True, validators=[django.core.validators.MinValueValidator(254, message='Weight must be between 25.4kg and 317.5kg'), django.core.validators.MaxValueValidator(3175, message='Weight must be between 25.4kg and 317.5kg')])),
+                ('imperial', models.PositiveIntegerField(blank=True, null=True, validators=[django.core.validators.MinValueValidator(56, message='Weight must be between 4 stone and 50 stone'), django.core.validators.MaxValueValidator(700, message='Weight must be between 4 stone and 50 stone')])),
+                ('response_set', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='weight_response', to='questions.responseset')),
+            ],
+            options={
+                'abstract': False,
+            },
+        ),
+        migrations.RunPython(copy_weight_data, reverse_copy_weight_data),
+        migrations.RemoveField(
+            model_name='responseset',
+            name='weight_metric',
+        ),
+        migrations.RemoveField(
+            model_name='responseset',
+            name='weight_imperial',
+        ),
+    ]

lung_cancer_screening/questions/models/__init__.py

@@ -7,3 +7,5 @@
 from .gender_response import GenderResponse # noqa: F401
 from .height_response import HeightResponse # noqa: F401
 from .respiratory_conditions_response import RespiratoryConditionsResponse # noqa: F401
+from .sex_at_birth_response import SexAtBirthResponse # noqa: F401
+from .weight_response import WeightResponse # noqa: F401

lung_cancer_screening/questions/models/weight_response.py

@@ -0,0 +1,40 @@
+from django.db import models
+from django.core.exceptions import ValidationError
+from django.core.validators import MaxValueValidator, MinValueValidator
+from decimal import Decimal
+
+from .base import BaseModel
+from .response_set import ResponseSet
+
+
+class WeightResponse(BaseModel):
+    MIN_WEIGHT_METRIC = 254
+    MAX_WEIGHT_METRIC = 3175
+    MAX_WEIGHT_IMPERIAL = 700
+    MIN_WEIGHT_IMPERIAL = 56
+
+    response_set = models.OneToOneField(ResponseSet, on_delete=models.CASCADE, related_name='weight_response')
+
+    metric = models.PositiveIntegerField(null=True, blank=True, validators=[
+        MinValueValidator(MIN_WEIGHT_METRIC, message="Weight must be between 25.4kg and 317.5kg"),
+        MaxValueValidator(MAX_WEIGHT_METRIC, message="Weight must be between 25.4kg and 317.5kg"),
+    ])
+    imperial = models.PositiveIntegerField(null=True, blank=True, validators=[
+        MinValueValidator(MIN_WEIGHT_IMPERIAL, message="Weight must be between 4 stone and 50 stone"),
+        MaxValueValidator(MAX_WEIGHT_IMPERIAL, message="Weight must be between 4 stone and 50 stone"),
+    ])
+
+    def clean(self):
+        if not self.metric and not self.imperial:
+            raise ValidationError("Either metric or imperial weight must be provided.")
+        if self.metric and self.imperial:
+            raise ValidationError("Cannot provide both metric and imperial weight.")
+
+    @property
+    def formatted(self):
+        if self.metric:
+            return f"{Decimal(self.metric) / 10}kg"
+        elif self.imperial:
+            value = Decimal(self.imperial)
+            return f"{value // 14} stone {value % 14} pounds"
+        return None