Return channel info from channel version snapshot

Author: AlexVelezLl

contentcuration/kolibri_public/tests/test_public_v1_api.py

@@ -172,3 +172,52 @@ def test_public_channel_lookup_channel_version_and_channel_tokens_have_same_keys
             set(channel_version_response.data[0].keys()),
             set(channel_response.data[0].keys()),
         )
+
+    def test_channel_version_token_returns_snapshot_info_not_current_channel_info(self):
+        """
+        When a channel version token is used, the returned name, description, and
+        thumbnail should come from the ChannelVersion snapshot captured at publish time,
+        not from the channel's current (possibly updated) values.
+        """
+        self.channel.main_tree.published = True
+        self.channel.main_tree.save()
+
+        # Set the channel info BEFORE the ChannelVersion is created so that the
+        # snapshot captures these values.
+        self.channel.name = "Original Published Name"
+        self.channel.description = "Original published description"
+        self.channel.thumbnail_encoding = {"base64": generated_base64encoding()}
+        self.channel.version = 3
+        self.channel.published_data = {"3": {"version_notes": "v3 notes"}}
+        self.channel.save()
+
+        # The ChannelVersion for version == channel.version is auto-created by
+        # Channel.on_update(); re-fetch it to get the snapshot that was captured.
+        channel_version = ChannelVersion.objects.get(channel=self.channel, version=3)
+        version_token = channel_version.new_token().token
+
+        # Now mutate the channel's info AFTER the snapshot was taken.
+        self.channel.name = "Updated Name — should NOT appear in response"
+        self.channel.description = "Updated description — should NOT appear in response"
+        self.channel.thumbnail_encoding = {"base64": "UPDATED_ENCODING"}
+        self.channel.save()
+
+        lookup_url = reverse(
+            "get_public_channel_lookup",
+            kwargs={"version": "v1", "identifier": version_token},
+        )
+        response = self.client.get(lookup_url)
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(len(response.data), 1)
+        result = response.data[0]
+
+        # Values must match the snapshot, not the current channel state.
+        self.assertEqual(result["name"], "Original Published Name")
+        self.assertEqual(result["description"], "Original published description")
+        self.assertEqual(result["icon_encoding"], generated_base64encoding())
+
+        # Sanity-check: confirm the channel itself now has the updated values.
+        self.channel.refresh_from_db()
+        self.assertNotEqual(result["name"], self.channel.name)
+        self.assertNotEqual(result["description"], self.channel.description)

contentcuration/kolibri_public/views_v1.py

@@ -21,7 +21,6 @@
 from contentcuration.decorators import cache_no_user_data
 from contentcuration.models import Channel
 from contentcuration.models import ChannelVersion
-from contentcuration.serializers import get_thumbnail_encoding
 from contentcuration.serializers import PublicChannelSerializer
 
 
@@ -40,6 +39,12 @@ def _get_version_notes(channel, channel_version):
     return OrderedDict(sorted(data.items()))
 
 
+def get_thumbnail_encoding(channel_version):
+    if channel_version.channel_thumbnail_encoding:
+        return channel_version.channel_thumbnail_encoding.get("base64")
+    return None
+
+
 def _serialize_channel_version(channel_version_qs):
     channel_version = channel_version_qs.first()
     if not channel_version or not channel_version.channel:
@@ -48,12 +53,12 @@ def _serialize_channel_version(channel_version_qs):
     channel = channel_version.channel
     return [
         {
-            "id": channel.id,
-            "name": channel.name,
-            "language": channel.language_id,
+            "id": channel_version.channel_id,
+            "name": channel_version.channel_name,
+            "language": channel_version.channel_language_id,
             "public": channel.public,
-            "description": channel.description,
-            "icon_encoding": get_thumbnail_encoding(channel),
+            "description": channel_version.channel_description,
+            "icon_encoding": get_thumbnail_encoding(channel_version),
             "version_notes": _get_version_notes(channel, channel_version),
             "version": channel_version.version,
             "kind_count": channel_version.kind_count,