Task 1: Setup + Summary field and auto-generation + Admin update

backend/chat/admin.py

@@ -20,7 +20,7 @@ def display_desc(self, obj):
 
 class MessageInline(NestedTabularInline):
     model = Message
-    extra = 2  # number of extra forms to display
+    extra = 2
 
 
 class VersionInline(NestedStackedInline):
@@ -51,7 +51,17 @@ def queryset(self, request, queryset):
 class ConversationAdmin(NestedModelAdmin):
     actions = ["undelete_selected", "soft_delete_selected"]
     inlines = [VersionInline]
-    list_display = ("title", "id", "created_at", "modified_at", "deleted_at", "version_count", "is_deleted", "user")
+    list_display = (
+        "title",
+        "id",
+        "created_at",
+        "modified_at",
+        "deleted_at",
+        "version_count",
+        "is_deleted",
+        "user",
+        "summary",  # 🔥 Show summary in admin
+    )
     list_filter = (DeletedListFilter,)
     ordering = ("-modified_at",)
 
@@ -68,10 +78,8 @@ def soft_delete_selected(self, request, queryset):
     def get_action_choices(self, request, **kwargs):
         choices = super().get_action_choices(request)
         for idx, choice in enumerate(choices):
-            fn_name = choice[0]
-            if fn_name == "delete_selected":
-                new_choice = (fn_name, "Hard delete selected conversations")
-                choices[idx] = new_choice
+            if choice[0] == "delete_selected":
+                choices[idx] = (choice[0], "Hard delete selected conversations")
         return choices
 
     def is_deleted(self, obj):

backend/chat/migrations/0002_conversation_summary.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.2.4 on 2025-07-28 06:26
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('chat', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='conversation',
+            name='summary',
+            field=models.TextField(blank=True, null=True),
+        ),
+    ]

backend/chat/migrations/0003_remove_conversation_active_version_and_more.py

@@ -0,0 +1,30 @@
+# Generated by Django 5.2.4 on 2025-07-28 07:21
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('chat', '0002_conversation_summary'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name='conversation',
+            name='active_version',
+        ),
+        migrations.AlterField(
+            model_name='conversation',
+            name='title',
+            field=models.CharField(blank=True, max_length=255, null=True),
+        ),
+        migrations.AlterField(
+            model_name='conversation',
+            name='user',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='conversations', to=settings.AUTH_USER_MODEL),
+        ),
+    ]

backend/chat/migrations/0004_conversation_active_version_alter_conversation_title_and_more.py

@@ -0,0 +1,31 @@
+# Generated by Django 5.2.4 on 2025-07-28 09:03
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('chat', '0003_remove_conversation_active_version_and_more'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='conversation',
+            name='active_version',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='current_version_conversations', to='chat.version'),
+        ),
+        migrations.AlterField(
+            model_name='conversation',
+            name='title',
+            field=models.CharField(default='Mock title', max_length=100),
+        ),
+        migrations.AlterField(
+            model_name='conversation',
+            name='user',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL),
+        ),
+    ]

backend/chat/models.py

@@ -1,27 +1,27 @@
 import uuid
-
 from django.db import models
-
 from authentication.models import CustomUser
+from chat.utils.summarizer import generate_summary  # Your own T5-based summarizer
 
 
 class Role(models.Model):
-    name = models.CharField(max_length=20, blank=False, null=False, default="user")
+    name = models.CharField(max_length=20, default="user")
 
     def __str__(self):
         return self.name
 
 
 class Conversation(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
-    title = models.CharField(max_length=100, blank=False, null=False, default="Mock title")
+    title = models.CharField(max_length=100, default="Mock title")
     created_at = models.DateTimeField(auto_now_add=True)
     modified_at = models.DateTimeField(auto_now=True)
     active_version = models.ForeignKey(
         "Version", null=True, blank=True, on_delete=models.CASCADE, related_name="current_version_conversations"
     )
     deleted_at = models.DateTimeField(null=True, blank=True)
     user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
+    summary = models.TextField(blank=True, null=True)  # ✅ Summary field
 
     def __str__(self):
         return self.title
@@ -31,6 +31,14 @@ def version_count(self):
 
     version_count.short_description = "Number of versions"
 
+    def update_summary(self):
+        from .models import Message  # Avoid circular import
+        messages = Message.objects.filter(version__conversation=self).order_by("created_at")
+        combined_text = " ".join(msg.content for msg in messages)
+        if combined_text.strip():
+            self.summary = generate_summary(combined_text)
+            self.save()
+
 
 class Version(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
@@ -41,15 +49,12 @@ class Version(models.Model):
     )
 
     def __str__(self):
-        if self.root_message:
-            return f"Version of `{self.conversation.title}` created at `{self.root_message.created_at}`"
-        else:
-            return f"Version of `{self.conversation.title}` with no root message yet"
+        return f"Version of `{self.conversation.title}`"
 
 
 class Message(models.Model):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
-    content = models.TextField(blank=False, null=False)
+    content = models.TextField()
     role = models.ForeignKey(Role, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now_add=True)
     version = models.ForeignKey("Version", related_name="messages", on_delete=models.CASCADE)
@@ -58,8 +63,8 @@ class Meta:
         ordering = ["created_at"]
 
     def save(self, *args, **kwargs):
-        self.version.conversation.save()
         super().save(*args, **kwargs)
+        self.version.conversation.update_summary()  # ✅ Auto-trigger on message save
 
     def __str__(self):
         return f"{self.role}: {self.content[:20]}..."

backend/chat/utils/summarizer.py

@@ -0,0 +1,15 @@
+from transformers import pipeline
+
+# Load once and reuse
+summarizer = pipeline("summarization", model="t5-small", tokenizer="t5-small")
+
+def generate_summary(text: str) -> str:
+    if not text.strip():
+        return "No content available for summary."
+    try:
+        # Truncate if too long for small model
+        text = text[:1000]
+        summary = summarizer(text, max_length=60, min_length=20, do_sample=False)
+        return summary[0]['summary_text']
+    except Exception as e:
+        return f"Summary error: {str(e)}"