scroll to the right page in redirects to card list

src/main.rs

@@ -34,18 +34,30 @@ pub struct ListContext<'a> {
     pub pages: usize,
 }
 
+const per_page: usize = 20;
+
+fn find_page_with_card(store : &Store, card_id : usize) -> Option<usize> {
+    if let Some((n, _)) = store.data.cards.iter().enumerate().find(|(_n, (id, _card))| **id == card_id) {
+        Some(n / per_page)
+    } else {
+        None
+    }
+}
+
 #[get("/?<page>&<card>")]
 fn route_index(store: State<RwLock<Store>>, page: Option<usize>, card: Option<usize>) -> Template {
     let rg = store.read();
 
-    let per_page: usize = 20;
+
     let mut page = page.unwrap_or_default();
     let n_pages = (rg.data.cards.len() as f64 / per_page as f64).ceil() as usize;
 
     if let Some(card_id) = card {
-        if let Some((n, _)) = rg.data.cards.iter().enumerate().find(|(_n, (id, _card))| **id == card_id) {
-            page = n / per_page;
-        }
+        page = find_page_with_card(&rg, card_id).unwrap_or(page);
+    }
+
+    if page >= n_pages {
+        page = n_pages - 1;
     }
 
     let context = ListContext {
@@ -250,9 +262,11 @@ fn route_edit_save(id: usize, form: Form<MapFromForm>, store: State<RwLock<Store
 fn route_delete(id: usize, store: State<RwLock<Store>>) -> Redirect {
     let mut rg = store.write();
 
+    let page = find_page_with_card(&rg, id).unwrap_or(0);
+
     rg.delete_card(id);
 
-    Redirect::found(uri!(route_index: page=_, card=_))
+    Redirect::found(uri!(route_index: page=page, card=_))
 }
 
 fn main() {