cart and buy page

src/controllers/cart.rs

@@ -1,4 +1,5 @@
 use crate::{controllers::i18n::current_lang, shared::money::format_price, models::products};
+use axum::{http::HeaderMap, response::Redirect};
 use axum_extra::extract::cookie::{Cookie, CookieJar, SameSite};
 use loco_rs::prelude::*;
 use sea_orm::{ColumnTrait, EntityTrait, QueryFilter};
@@ -96,6 +97,8 @@ async fn add(
 async fn update(
     jar: CookieJar,
     State(ctx): State<AppContext>,
+    ViewEngine(v): ViewEngine<TeraView>,
+    headers: HeaderMap,
     Form(form): Form<UpdateForm>,
 ) -> Result<Response> {
     let stock = published_product(&ctx, form.product_id)
@@ -110,19 +113,57 @@ async fn update(
     }
     items.retain(|(_, qty)| *qty > 0);
 
-    format::render()
-        .cookies(&[cart_cookie(serialize_cart(&items))])?
-        .redirect("/cart")
+    let jar = jar.add(cart_cookie(serialize_cart(&items)));
+    cart_response(&ctx, &v, jar, &headers).await
 }
 
 #[debug_handler]
-async fn remove(jar: CookieJar, Form(form): Form<RemoveForm>) -> Result<Response> {
+async fn remove(
+    jar: CookieJar,
+    State(ctx): State<AppContext>,
+    ViewEngine(v): ViewEngine<TeraView>,
+    headers: HeaderMap,
+    Form(form): Form<RemoveForm>,
+) -> Result<Response> {
     let mut items = parse_cart(&jar);
     items.retain(|(id, _)| *id != form.product_id);
 
-    format::render()
-        .cookies(&[cart_cookie(serialize_cart(&items))])?
-        .redirect("/cart")
+    let jar = jar.add(cart_cookie(serialize_cart(&items)));
+    cart_response(&ctx, &v, jar, &headers).await
+}
+
+/// Response after a cart mutation: for an htmx request, just the `#cart-body`
+/// fragment (so the page never fully reloads); otherwise a redirect back to
+/// `/cart` for no-JS fallback. `jar` must already hold the updated cart cookie.
+async fn cart_response(
+    ctx: &AppContext,
+    v: &TeraView,
+    jar: CookieJar,
+    headers: &HeaderMap,
+) -> Result<Response> {
+    if !headers.contains_key("HX-Request") {
+        return Ok((jar, Redirect::to("/cart")).into_response());
+    }
+
+    let (lines, valid, total) = resolve_cart(ctx, &jar).await?;
+    let currency = lines
+        .first()
+        .and_then(|line| line["currency"].as_str())
+        .unwrap_or("EUR")
+        .to_string();
+    // Persist the re-validated cookie (drops now-invalid lines).
+    let jar = jar.add(cart_cookie(serialize_cart(&valid)));
+    let response = format::view(
+        v,
+        "shop/_cart_body.html",
+        json!({
+            "items": lines,
+            "total": format_price(total),
+            "currency": currency,
+            "lang": current_lang(&jar),
+        }),
+    )?;
+    Ok((jar, response).into_response())
 }
 
 /// Resolve the cart cookie into priced line items, dropping anything that is no