M1: retain selection after permanent photo deletion

Reuse the landed current-view deletion selection logic for photo.deletePermanently, retaining survivors or choosing the next neighbour and the previous at the end. Preserve catalog-only deletion and existing undo/persistence behavior.

Refs #441, #451, #545.

crates/engine/src/cmd/library.rs

@@ -7,6 +7,20 @@ use serde_json::{Value, json};
 use super::{CommandSpec, always, bad, bool_or, cmd, has_active, has_selection, ok, str_param};
 use crate::{LibrarySource, Result, Selection, Session};
 
+fn select_after_deletion(s: &mut Session, before: &[PhotoId]) {
+    let at = before.iter().position(|id| Some(*id) == s.selection.active);
+    let remaining: std::collections::HashSet<_> = s.visible_cloned().into_iter().collect();
+    s.selection.ids.retain(|id| remaining.contains(id));
+    s.selection.active = s.selection.active.filter(|id| remaining.contains(id)).or_else(|| s.selection.ids.first().copied());
+    if s.selection.active.is_none()
+        && let Some(at) = at
+    {
+        // Keep culling near the deleted photo: next visible survivor, or the previous one at the end.
+        let neighbour = before.iter().skip(at.saturating_add(1)).chain(before.iter().take(at).rev()).find(|id| remaining.contains(id));
+        s.selection = neighbour.map(|id| Selection::single(*id)).unwrap_or_default();
+    }
+}
+
 /// The auto-import folder's visible files with their sizes (the file-system half of
 /// `library.autoImportScan`; the app lists on a worker thread and passes `listing`).
 pub fn list_auto_import_folder(folder: &str) -> std::result::Result<Vec<(String, u64)>, String> {
@@ -662,18 +676,8 @@ pub fn specs() -> Vec<CommandSpec> {
         // ---- delete / restore
         cmd!("photo.delete", "Delete Photo", ["Photo"], Some("Delete"), "{ids?} — moves to Recently Deleted", has_selection, |s, p| {
             let before = s.visible_cloned();
-            let at = before.iter().position(|id| Some(*id) == s.selection.active);
             let v = for_targets(s, p, "Delete", |id| Some(Op::SetDeleted { id, deleted: true }))?;
-            let remaining: std::collections::HashSet<_> = s.visible_cloned().into_iter().collect();
-            s.selection.ids.retain(|id| remaining.contains(id));
-            s.selection.active = s.selection.active.filter(|id| remaining.contains(id)).or_else(|| s.selection.ids.first().copied());
-            if s.selection.active.is_none()
-                && let Some(at) = at
-            {
-                // Keep culling near the deleted photo: next visible survivor, or the previous one at the end.
-                let neighbour = before.iter().skip(at.saturating_add(1)).chain(before.iter().take(at).rev()).find(|id| remaining.contains(id));
-                s.selection = neighbour.map(|id| Selection::single(*id)).unwrap_or_default();
-            }
+            select_after_deletion(s, &before);
             Ok(v)
         }),
         cmd!("photo.restore", "Restore", ["Photo"], None, "{ids?}", has_selection, |s, p| for_targets(s, p, "Restore", |id| Some(Op::SetDeleted {
@@ -699,10 +703,11 @@ pub fn specs() -> Vec<CommandSpec> {
             }
         ),
         cmd!("photo.deletePermanently", "Delete Permanently", ["Photo"], None, "{ids?}", has_selection, |s, p| {
+            let before = s.visible_cloned();
             let t = s.targets(p);
             let op = s.catalog.delete_photos_permanently_ops(&t);
             s.commit("Delete Permanently", op)?;
-            s.selection = Selection::default();
+            select_after_deletion(s, &before);
             Ok(json!({"deleted": t.len()}))
         }),
         // ---- metadata

crates/engine/src/tests.rs

@@ -198,6 +198,60 @@ fn deleting_explicit_targets_keeps_the_surviving_selection() {
     assert_eq!(s.selection, Selection::single(visible[8]), "partial deletion retains a selected survivor");
 }
 
+#[test]
+fn permanently_deleting_photos_selects_a_neighbour_in_recently_deleted() {
+    for params in [json!({}), json!({"key": "fileName", "ascending": false}), json!({"key": "random", "seed": 123})] {
+        for at_end in [false, true] {
+            let mut s = demo();
+            s.execute("library.selectAll", &json!({})).unwrap();
+            s.execute("photo.delete", &json!({})).unwrap();
+            s.execute("library.source", &json!({"kind": "recentlyDeleted"})).unwrap();
+            s.execute("library.sort", &params).unwrap();
+            s.execute("library.filter", &json!({"rating": 2})).unwrap();
+            let visible = s.visible_cloned();
+            assert!(visible.len() > 5);
+            let at = if at_end { visible.len() - 2 } else { visible.len() / 2 };
+            let deleted = &visible[at..at + 2];
+            s.execute("library.select", &json!({"ids": deleted, "active": deleted[0]})).unwrap();
+            let snapshot = s.catalog.to_snapshot();
+            let undo_len = s.undo.len();
+            let r = s.execute("photo.deletePermanently", &json!({})).unwrap();
+            assert_eq!(r["deleted"], 2);
+            let expected = if at_end { visible[at - 1] } else { visible[at + 2] };
+            assert_eq!(s.selection, Selection::single(expected), "sort {params}, end {at_end}");
+            assert!(deleted.iter().all(|id| s.catalog.photo(*id).is_none()));
+            assert_eq!(s.undo.len(), undo_len + 1);
+            let removed = s.catalog.to_snapshot();
+            s.execute("edit.undo", &json!({})).unwrap();
+            assert_eq!(s.catalog.to_snapshot(), snapshot);
+            s.execute("edit.redo", &json!({})).unwrap();
+            assert_eq!(s.catalog.to_snapshot(), removed);
+        }
+    }
+    let mut s = demo();
+    s.execute("library.selectAll", &json!({})).unwrap();
+    s.execute("photo.deletePermanently", &json!({})).unwrap();
+    assert!(s.visible().is_empty());
+    assert_eq!(s.selection, Selection::default());
+}
+
+#[test]
+fn permanently_deleting_explicit_targets_keeps_the_surviving_selection() {
+    let mut s = demo();
+    let visible = s.visible_cloned();
+    s.execute("library.select", &json!({"ids": [visible[8], visible[9]], "active": visible[9]})).unwrap();
+    let before = s.selection.clone();
+    s.execute("photo.deletePermanently", &json!({"ids": [visible[3]]})).unwrap();
+    assert_eq!(s.selection, before, "deleting an unselected photo doesn't change selection");
+    s.execute("photo.deletePermanently", &json!({"ids": [visible[9]]})).unwrap();
+    assert_eq!(s.selection, Selection::single(visible[8]), "partial deletion retains a selected survivor");
+    let before = s.selection.clone();
+    let snapshot = s.catalog.to_snapshot();
+    assert!(s.execute("photo.deletePermanently", &json!({"ids": [999_999]})).is_err());
+    assert_eq!(s.selection, before, "a refused deletion doesn't change selection");
+    assert_eq!(s.catalog.to_snapshot(), snapshot);
+}
+
 #[test]
 fn masks_crop_and_render() {
     let mut s = demo();

crates/engine/src/tests_import.rs

@@ -974,8 +974,27 @@ fn emptying_trashed_photos_of_one_album_and_stack_leaves_nothing_dangling() {
 fn deleting_several_photos_permanently_leaves_nothing_dangling() {
     let (mut s, src, ids, al) = two_trashed_in_album_and_stack("trash-perm-refs");
     s.execute("library.select", &json!({"ids": ids})).unwrap();
+    let files = [src.join("a.png"), src.join("b.png")].map(|path| {
+        let bytes = std::fs::read(&path).unwrap();
+        (path, bytes)
+    });
+    let snapshot = s.catalog.to_snapshot();
+    s.drain_log();
     s.execute("photo.deletePermanently", &json!({"ids": ids})).unwrap();
     assert!(s.catalog.album(lightcraft_catalog::AlbumId(al)).unwrap().photos.is_empty());
+    assert!(ids.iter().all(|i| s.catalog.photo(lightcraft_catalog::PhotoId(*i)).is_none()));
+    let removed = s.catalog.to_snapshot();
+    let log: String = s.drain_log().iter().map(lightcraft_catalog::Catalog::op_to_log_line).collect();
+    let mut reopened = lightcraft_catalog::Catalog::from_snapshot(&snapshot).unwrap();
+    reopened.replay(&log).unwrap();
+    assert_eq!(reopened.to_snapshot(), removed);
+    s.execute("edit.undo", &json!({})).unwrap();
+    assert_eq!(s.catalog.to_snapshot(), snapshot, "one undo restores photos, album and stack");
+    s.execute("edit.redo", &json!({})).unwrap();
+    assert_eq!(s.catalog.to_snapshot(), removed);
+    for (path, bytes) in files {
+        assert_eq!(std::fs::read(path).unwrap(), bytes, "permanent deletion only removes catalog records");
+    }
     let _ = std::fs::remove_dir_all(&src);
 }