feat: content provenance and complete frame management workflows

pigway_frame_flow/display/service.py

@@ -153,8 +153,20 @@ class DisplayService:
 
     def content_asset(self, content):
         if isinstance(content, TemplateContent):
-            data = self.renderer.render(content.template, content.data, content.profile)
-            return self.assets.put(data, content.template + ".jpg", "generated")
+            values = self.renderer.resolve(content.template, content.data)
+            data = self.renderer.render(content.template, values, content.profile)
+            asset = self.assets.put(data, content.template + ".jpg", "generated")
+            source = {
+                "type": "template",
+                "template": content.template,
+                "data": self.settings.sanitize(values),
+                "profile": content.profile,
+            }
+            self.db.execute(
+                "INSERT OR REPLACE INTO asset_sources VALUES(?,?)",
+                (asset["asset_id"], encode(source)),
+            )
+            return asset
         if isinstance(content, URLContent):
             data = self.assets.fetch_url(content.url)
         elif isinstance(content, ImageContent) and content.asset_id:
@@ -167,6 +179,38 @@ class DisplayService:
             convert(data, content.fit, content.profile), content.name
         )
 
+    def current_content(self, device_id):
+        device = self.registry.get(device_id).device()
+        image_id = device.current_content.id
+        row = self.db.one(
+            "SELECT * FROM image_sources WHERE device_id=? AND image_id=?",
+            (device_id, image_id),
+        )
+        source = json.loads(row["payload"]) if row else None
+        # Acknowledged upload is not proof that the frame has refreshed yet.
+        if row:
+            op = self.operation(row["operation_id"])
+            if op["status"] not in ("COMPLETED", "SYNCING"):
+                source = None
+        state = self.state(device_id)
+        return {
+            "device_id": device_id,
+            "image_id": image_id,
+            "synced": device.current_content.synced,
+            "source_known": source is not None,
+            "source": source,
+            "asset_id": row["asset_id"] if row and source else None,
+            "operation_id": row["operation_id"] if row and source else None,
+            "preview_url": f"/api/v1/devices/{device_id}/images/{image_id}/file?thumbnail=true"
+            if image_id
+            else None,
+            "previous_image_id": state["previous_image_id"],
+            "overrides": self.db.all(
+                "SELECT id,image_id,priority,expires_at FROM overrides WHERE device_id=? ORDER BY priority DESC,created_at DESC",
+                (device_id,),
+            ),
+        }
+
     def top(self, device_id):
         return self.db.one(
             "SELECT * FROM overrides WHERE device_id=? AND expires_at>? ORDER BY priority DESC,created_at DESC LIMIT 1",
@@ -268,6 +312,14 @@ class DisplayService:
                 raise FlowError(E.CONFLICT, "Current image needs confirmation", 409)
             self._start_write(id)
             driver.delete(image_id)
+            for suffix in [".original", "-thumb.jpg"]:
+                (
+                    self.settings.data_dir / "cache" / f"{device_id}-{image_id}{suffix}"
+                ).unlink(missing_ok=True)
+            self.db.execute(
+                "DELETE FROM image_sources WHERE device_id=? AND image_id=?",
+                (device_id, image_id),
+            )
             driver.invalidate()
             self.update(id, "COMPLETED", {"image_id": image_id})
             self.db.history(op, "COMPLETED")
@@ -334,6 +386,15 @@ class DisplayService:
         if asset:
             self.assets.promote(asset["asset_id"])
             result["rendered_asset_id"] = asset["asset_id"]
+            source = self.db.one(
+                "SELECT payload FROM asset_sources WHERE asset_id=?",
+                (asset["asset_id"],),
+            )
+            descriptor = source["payload"] if source else encode({"type": "image"})
+            self.db.execute(
+                "INSERT OR REPLACE INTO image_sources VALUES(?,?,?,?,?)",
+                (device_id, image_id, asset["asset_id"], id, descriptor),
+            )
         self.update(id, "SYNCING", result)
         driver.invalidate()
         if request.options.restore_previous: