page is better in shop now

src/controllers/shop.rs

@@ -22,8 +22,21 @@ use crate::{
     views::shop as view,
 };
 
-/// Results per page in the storefront listing/search.
+/// Default results per page in the storefront listing/search.
 const PER_PAGE: usize = 24;
+/// Allowed per-page choices offered in the toolbar; any other value falls back
+/// to [`PER_PAGE`].
+const PER_PAGE_OPTIONS: [usize; 3] = [24, 48, 96];
+
+/// Resolve the requested per-page count to one of [`PER_PAGE_OPTIONS`],
+/// defaulting to [`PER_PAGE`].
+fn resolve_per_page(params: &SearchParams) -> usize {
+    params
+        .per_page
+        .map(|p| p as usize)
+        .filter(|p| PER_PAGE_OPTIONS.contains(p))
+        .unwrap_or(PER_PAGE)
+}
 /// Hard cap on candidates a single text search considers before faceting; well
 /// above any realistic page of results for this catalog.
 const SEARCH_CAP: u64 = 1000;
@@ -40,6 +53,7 @@ struct SearchParams {
     in_stock: Option<String>,
     sort: Option<String>,
     page: Option<u32>,
+    per_page: Option<u32>,
 }
 
 /// A candidate product with everything the listing needs to filter, sort and
@@ -81,6 +95,9 @@ fn query_base(params: &SearchParams) -> String {
     if let Some(s) = params.sort.as_deref().filter(|s| !s.is_empty()) {
         ser.append_pair("sort", s);
     }
+    if let Some(p) = params.per_page.filter(|p| *p as usize != PER_PAGE) {
+        ser.append_pair("per_page", &p.to_string());
+    }
     ser.finish()
 }
 
@@ -198,14 +215,15 @@ async fn run_search(
     }
 
     // 7. Paginate.
+    let per_page = resolve_per_page(params);
     let total = items.len();
-    let pages = total.div_ceil(PER_PAGE).max(1);
+    let pages = total.div_ceil(per_page).max(1);
     let page = params.page.unwrap_or(1).clamp(1, pages as u32);
-    let start = (page as usize - 1) * PER_PAGE;
+    let start = (page as usize - 1) * per_page;
 
     // 8. Render only the current page's cards (images fetched per row).
     let mut rows = Vec::new();
-    for item in items.iter().skip(start).take(PER_PAGE) {
+    for item in items.iter().skip(start).take(per_page) {
         let image = product_images::first_for(ctx, item.product.id).await?;
         let cat_name = item.product.category_id.and_then(|id| category_name.get(&id).cloned());
         rows.push(view::product_card(
@@ -229,6 +247,8 @@ async fn run_search(
         "selected_category_id": selected_category.parse::<i32>().unwrap_or(-1),
         "uncategorized_count": uncategorized_count,
         "sort": sort,
+        "per_page": per_page,
+        "per_page_options": PER_PAGE_OPTIONS,
         "in_stock": in_stock_only,
         "min_price": params.min_price.clone().unwrap_or_default(),
         "max_price": params.max_price.clone().unwrap_or_default(),