ShopQuick - Priorities Rule 3 Revised

rule3_revised.swift

 func addProduct(product: Product) {
        
        let newProduct = Product(name: product.name, qty: 0)
        
        // if the product exists
        if self.doesProductExist(newProduct.name) {
            
            // if there is a last item purchased
            if let lastProduct = self.lastProductPurchased {
                
                // remove the last product purchased so it can be moved
                let currentLastProductPriority = self.findIndexForProductName(lastProduct.name)
                self.removeProductWithName(lastProduct.name)
                
                // insert the last product purchased directly above the current product
                if let existingIndex = self.findIndexForProductName(newProduct.name) {
                    self.insertProduct(lastProduct, atIndex: min(existingIndex, currentLastProductPriority!)) // Rule #3
                }
                
            } // else, do nothing -- Rule #2
            
        }
        else {
            // if there is a last item purchased
            if let lastProduct = self.lastProductPurchased {
                if let lastProductIndex = self.findIndexForProductName(lastProduct.name) {
                    // add the new product right after the last product purchased
                    self.insertProduct(newProduct, atIndex: lastProductIndex + 1) // Rule #1
                }
            }
            else {
                // just add the product to the end of the list
                self.products.append(newProduct) // Rule #0
            }
        }
        
        self.lastProductPurchased = newProduct
        
        self.saveProductsToDefaults()
    
    }