variants as a single product

repositories/productVariantLink.go

@@ -2,6 +2,7 @@ package repositories
 
 import (
 	"errors"
+	"strings"
 
 	"nearle/models"
 
@@ -158,3 +159,54 @@ func (r *productRepository) VariantsForProducts(tenantid, locationid int, produc
 	}
 	return out, nil
 }
+
+// variantLabelFor names the product's own size for the picker.
+//
+// The unit if it has one — "500g" is what a shopper is choosing between. A
+// product with no unit recorded falls back to its name rather than to an empty
+// label, because a blank option in a size picker is unpickable.
+func variantLabelFor(p models.Products) string {
+	unit := strings.TrimSpace(strings.TrimSpace(p.Unitvalue) + " " + strings.TrimSpace(p.Productunit))
+	if unit != "" {
+		return unit
+	}
+	return p.Productname
+}
+
+// VariantChildIDs is every product that is a size OF something else.
+//
+// These are the rows the customer app must not list on their own. A shop that
+// stocks Aachi Baby Fryums in 100g, 500g and 1kg has three product rows, and a
+// shopper should meet one product with three sizes — not three products that
+// happen to share a name and differ by a suffix they have to read carefully.
+//
+// One query for the whole tenant rather than per product: the alternative is a
+// lookup inside the loop that builds the response, which is the classic N+1 on
+// a listing that can run to hundreds of rows.
+//
+// A product that is a size of something is NOT deleted or hidden from the
+// merchant — the console still lists all three, because each has its own price,
+// its own barcode and its own shelf to restock.
+func (r *productRepository) VariantChildIDs(tenantid int) (map[int]bool, error) {
+	out := map[int]bool{}
+	if tenantid <= 0 {
+		return out, nil
+	}
+
+	var ids []int
+	err := r.db.Table("productvariants").
+		Where("tenantid = ?", tenantid).
+		Where("LOWER(COALESCE(status, 'active')) <> 'inactive'").
+		// A row that is its own parent would remove the group's only visible
+		// product. It should not exist — AddProductVariant refuses it — but a
+		// listing is the wrong place to discover that it does.
+		Where("variantproductid <> productid").
+		Pluck("variantproductid", &ids).Error
+	if err != nil {
+		return out, err
+	}
+	for _, id := range ids {
+		out[id] = true
+	}
+	return out, nil
+}