now products have different options, like different parameters

src/controllers/cart.rs

@@ -1,4 +1,4 @@
-use crate::{controllers::i18n::current_lang, shared::{guard, money::format_price, pricing}, models::products};
+use crate::{controllers::i18n::current_lang, shared::{guard, money::format_price, pricing}, models::{product_variants, products}};
 use axum::{
     http::{HeaderMap, StatusCode},
     response::Redirect,
@@ -15,22 +15,22 @@ const CART_MAX_AGE_DAYS: i64 = 30;
 
 #[derive(Debug, Deserialize)]
 struct AddForm {
-    product_id: i32,
+    variant_id: i32,
     quantity: Option<i32>,
 }
 
 #[derive(Debug, Deserialize)]
 struct UpdateForm {
-    product_id: i32,
+    variant_id: i32,
     quantity: i32,
 }
 
 #[derive(Debug, Deserialize)]
 struct RemoveForm {
-    product_id: i32,
+    variant_id: i32,
 }
 
-/// Parse the `cart` cookie ("id:qty,id:qty") into `(product_id, quantity)`
+/// Parse the `cart` cookie ("id:qty,id:qty") into `(variant_id, quantity)`
 /// pairs, silently dropping malformed or non-positive entries.
 pub(crate) fn parse_cart(jar: &CookieJar) -> Vec<(i32, i32)> {
     let Some(cookie) = jar.get(CART_COOKIE) else {
@@ -64,12 +64,23 @@ fn cart_cookie(value: String) -> Cookie<'static> {
         .build()
 }
 
-/// Look up a published product, returning its current stock cap.
-async fn published_product(ctx: &AppContext, id: i32) -> Result<Option<products::Model>> {
-    Ok(products::Entity::find_by_id(id)
+/// Look up a variant whose product is published, returning the variant together
+/// with its parent product (for name/slug/currency).
+async fn published_variant(
+    ctx: &AppContext,
+    variant_id: i32,
+) -> Result<Option<(product_variants::Model, products::Model)>> {
+    let Some(variant) = product_variants::Entity::find_by_id(variant_id)
+        .one(&ctx.db)
+        .await?
+    else {
+        return Ok(None);
+    };
+    let product = products::Entity::find_by_id(variant.product_id)
         .filter(products::Column::Published.eq(true))
         .one(&ctx.db)
-        .await?)
+        .await?;
+    Ok(product.map(|p| (variant, p)))
 }
 
 #[debug_handler]
@@ -79,16 +90,16 @@ async fn add(
     headers: HeaderMap,
     Form(form): Form<AddForm>,
 ) -> Result<Response> {
-    let Some(product) = published_product(&ctx, form.product_id).await? else {
+    let Some((variant, _product)) = published_variant(&ctx, form.variant_id).await? else {
         return Err(Error::NotFound);
     };
 
     let mut items = parse_cart(&jar);
     let add_qty = form.quantity.unwrap_or(1).max(1);
-    if let Some(entry) = items.iter_mut().find(|(id, _)| *id == product.id) {
-        entry.1 = (entry.1 + add_qty).min(product.stock);
+    if let Some(entry) = items.iter_mut().find(|(id, _)| *id == variant.id) {
+        entry.1 = (entry.1 + add_qty).min(variant.stock);
     } else {
-        items.push((product.id, add_qty.min(product.stock)));
+        items.push((variant.id, add_qty.min(variant.stock)));
     }
     items.retain(|(_, qty)| *qty > 0);
 
@@ -117,14 +128,14 @@ async fn update(
     headers: HeaderMap,
     Form(form): Form<UpdateForm>,
 ) -> Result<Response> {
-    let stock = published_product(&ctx, form.product_id)
+    let stock = published_variant(&ctx, form.variant_id)
         .await?
-        .map(|p| p.stock)
+        .map(|(v, _)| v.stock)
         .unwrap_or(0);
 
     let mut items = parse_cart(&jar);
     let clamped = form.quantity.clamp(0, stock);
-    if let Some(entry) = items.iter_mut().find(|(id, _)| *id == form.product_id) {
+    if let Some(entry) = items.iter_mut().find(|(id, _)| *id == form.variant_id) {
         entry.1 = clamped;
     }
     items.retain(|(_, qty)| *qty > 0);
@@ -142,7 +153,7 @@ async fn remove(
     Form(form): Form<RemoveForm>,
 ) -> Result<Response> {
     let mut items = parse_cart(&jar);
-    items.retain(|(id, _)| *id != form.product_id);
+    items.retain(|(id, _)| *id != form.variant_id);
 
     let jar = jar.add(cart_cookie(serialize_cart(&items)));
     cart_response(&ctx, &v, jar, &headers).await
@@ -192,38 +203,40 @@ pub(crate) async fn resolve_cart(
     // Resolve the cart entries to in-stock products first, then price them all
     // for the current viewer in one batch (the price depends on who's logged in).
     let user = guard::current_user(ctx, jar).await;
-    let mut items: Vec<(products::Model, i32)> = Vec::new();
+    let mut items: Vec<(product_variants::Model, products::Model, i32)> = Vec::new();
     for (id, qty) in parse_cart(jar) {
-        let Some(product) = published_product(ctx, id).await? else {
+        let Some((variant, product)) = published_variant(ctx, id).await? else {
             continue;
         };
-        let qty = qty.clamp(0, product.stock);
+        let qty = qty.clamp(0, variant.stock);
         if qty == 0 {
             continue;
         }
-        items.push((product, qty));
+        items.push((variant, product, qty));
     }
-    let products_only: Vec<products::Model> = items.iter().map(|(p, _)| p.clone()).collect();
-    let priced = pricing::price_many(ctx, &products_only, user.as_ref()).await?;
+    let variants_only: Vec<product_variants::Model> =
+        items.iter().map(|(v, _, _)| v.clone()).collect();
+    let priced = pricing::price_variants(ctx, &variants_only, user.as_ref()).await?;
 
     let mut lines = Vec::new();
     let mut valid = Vec::new();
     let mut total: i64 = 0;
-    for ((product, qty), priced) in items.iter().zip(priced.iter()) {
+    for ((variant, product, qty), priced) in items.iter().zip(priced.iter()) {
         let unit_price = priced.price_cents;
         let line_total = unit_price * i64::from(*qty);
         total += line_total;
-        valid.push((product.id, *qty));
+        valid.push((variant.id, *qty));
         lines.push(json!({
-            "id": product.id,
+            "id": variant.id,
             "name": product.name,
+            "variant_label": variant.label,
             "slug": product.slug,
             "price": format_price(unit_price),
             "regular_price": format_price(priced.regular_cents),
             "on_sale": priced.is_reduced(),
             "currency": product.currency,
             "quantity": qty,
-            "stock": product.stock,
+            "stock": variant.stock,
             "line_total": format_price(line_total),
         }));
     }