refactor: get_snapshot_group can identify latest~N snapshot

Author: nardoor

crates/core/src/commands/snapshots.rs

@@ -1,4 +1,4 @@
-//! `smapshot` subcommand
+//! `snapshot` subcommand
 
 use crate::{
     Progress,
@@ -22,6 +22,7 @@ use crate::{
 ///
 /// * `repo` - The repository to get the snapshots from.
 /// * `ids` - The ids of the snapshots to get.
+///   * each `id` can use an actual (short) id "01a2b3c4" or "latest" or "latest~N"
 /// * `group_by` - The criterion to group the snapshots by.
 /// * `filter` - The filter to apply to the snapshots.
 ///
@@ -37,25 +38,14 @@ pub(crate) fn get_snapshot_group<P: ProgressBars, S: Open>(
     let pb = &repo.pb;
     let dbe = repo.dbe();
     let p = pb.progress_counter("getting snapshots...");
-    let groups = match ids {
-        [] => SnapshotFile::group_from_backend(dbe, filter, group_by, &p)?,
-        [id] if id == "latest" => SnapshotFile::group_from_backend(dbe, filter, group_by, &p)?
-            .into_iter()
-            .map(|(group, mut snaps)| {
-                snaps.sort_unstable();
-                let last_idx = snaps.len() - 1;
-                snaps.swap(0, last_idx);
-                snaps.truncate(1);
-                (group, snaps)
-            })
-            .collect::<Vec<_>>(),
-        _ => {
-            let item = (
-                SnapshotGroup::default(),
-                SnapshotFile::from_ids(dbe, ids, &p)?,
-            );
-            vec![item]
-        }
+    let groups = if ids.is_empty() {
+        SnapshotFile::group_from_backend(dbe, filter, group_by, &p)?
+    } else {
+        let item = (
+            SnapshotGroup::default(),
+            SnapshotFile::from_strs(dbe, ids, |_| true, &p)?,
+        );
+        vec![item]
     };
     p.finish();