Add new fields to UserVisit (#25)

This is an optimization to allow filtering by os/browser/device directly in the database.

h/t @mboboc

user_visit/migrations/0004_add_user_agent_fields.py

@@ -0,0 +1,27 @@
+# Generated by Django 3.2.23 on 2023-11-02 10:17
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("user_visit", "0003_uservisit_context"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="uservisit",
+            name="browser",
+            field=models.CharField(blank=True, default="", max_length=200),
+        ),
+        migrations.AddField(
+            model_name="uservisit",
+            name="device",
+            field=models.CharField(blank=True, default="", max_length=200),
+        ),
+        migrations.AddField(
+            model_name="uservisit",
+            name="os",
+            field=models.CharField(blank=True, default="", max_length=200),
+        ),
+    ]

user_visit/models.py

@@ -42,6 +42,9 @@ def build(self, request: HttpRequest, timestamp: datetime.datetime) -> UserVisit
             context=REQUEST_CONTEXT_EXTRACTOR(request),
         )
         uv.hash = uv.md5().hexdigest()
+        uv.browser = uv.user_agent.get_browser()[:200]
+        uv.device = uv.user_agent.get_device()[:200]
+        uv.os = uv.user_agent.get_os()[:200]
         return uv
 
 
@@ -82,6 +85,21 @@ class UserVisit(models.Model):
         help_text=_lazy("Client User-Agent HTTP header"),
         blank=True,
     )
+    browser = models.CharField(
+        max_length=200,
+        blank=True,
+        default="",
+    )
+    device = models.CharField(
+        max_length=200,
+        blank=True,
+        default="",
+    )
+    os = models.CharField(
+        max_length=200,
+        blank=True,
+        default="",
+    )
     uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
     hash = models.CharField(  # noqa: A003
         max_length=32,