Apply snapshots automatically on empty taskdbs

taskchampion/src/server/local.rs

@@ -160,6 +160,10 @@ impl Server for LocalServer {
         // the local server never requests a snapshot, so it should never get one
         unreachable!()
     }
+
+    fn get_snapshot(&mut self) -> anyhow::Result<Option<(VersionId, Snapshot)>> {
+        Ok(None)
+    }
 }
 
 #[cfg(test)]

taskchampion/src/server/remote/mod.rs

@@ -152,4 +152,25 @@ impl Server for RemoteServer {
             .send_bytes(ciphertext.as_ref())
             .map(|_| ())?)
     }
+
+    fn get_snapshot(&mut self) -> anyhow::Result<Option<(VersionId, Snapshot)>> {
+        let url = format!("{}/v1/client/snapshot", self.origin);
+        match self
+            .agent
+            .get(&url)
+            .set("X-Client-Key", &self.client_key.to_string())
+            .call()
+        {
+            Ok(resp) => {
+                let version_id = get_uuid_header(&resp, "X-Version-Id")?;
+                let ciphertext = Ciphertext::from_resp(resp, SNAPSHOT_CONTENT_TYPE)?;
+                let snapshot = ciphertext
+                    .open(&self.encryption_secret, version_id)?
+                    .payload;
+                Ok(Some((version_id, snapshot)))
+            }
+            Err(ureq::Error::Status(status, _)) if status == 404 => Ok(None),
+            Err(err) => Err(err.into()),
+        }
+    }
 }

taskchampion/src/server/test.rs

@@ -12,9 +12,8 @@ struct Version {
     history_segment: HistorySegment,
 }
 
-#[derive(Clone)]
-
 /// TestServer implements the Server trait with a test implementation.
+#[derive(Clone)]
 pub(crate) struct TestServer(Arc<Mutex<Inner>>);
 
 pub(crate) struct Inner {
@@ -35,6 +34,7 @@ impl TestServer {
             snapshot: None,
         })))
     }
+    // feel free to add any test utility functions here
 
     /// Get a boxed Server implementation referring to this TestServer
     pub(crate) fn server(&self) -> Box<dyn Server> {
@@ -51,6 +51,12 @@ impl TestServer {
         let inner = self.0.lock().unwrap();
         inner.snapshot.as_ref().cloned()
     }
+
+    /// Delete a version from storage
+    pub(crate) fn delete_version(&mut self, parent_version_id: VersionId) {
+        let mut inner = self.0.lock().unwrap();
+        inner.versions.remove(&parent_version_id);
+    }
 }
 
 impl Server for TestServer {
@@ -119,4 +125,9 @@ impl Server for TestServer {
         inner.snapshot = Some((version_id, snapshot));
         Ok(())
     }
+
+    fn get_snapshot(&mut self) -> anyhow::Result<Option<(VersionId, Snapshot)>> {
+        let inner = self.0.lock().unwrap();
+        Ok(inner.snapshot.clone())
+    }
 }

taskchampion/src/server/types.rs

@@ -65,4 +65,6 @@ pub trait Server {
 
     /// Add a snapshot on the server
     fn add_snapshot(&mut self, version_id: VersionId, snapshot: Snapshot) -> anyhow::Result<()>;
+
+    fn get_snapshot(&mut self) -> anyhow::Result<Option<(VersionId, Snapshot)>>;
 }