Hw-1

gradle.properties

@@ -1,2 +1,3 @@
 org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
 kotlin.code.style=official
+org.gradle.java.home=/home/karassad/android-studio/android-studio/jbr

src/main/kotlin/orders/Order.kt

@@ -18,21 +18,24 @@ class Order(
      */
     fun addProduct(product: Product?) {
         // TODO: add product to _products, ignore null
+        product?.let {_products.add(it)}
     }
 
     /**
      * Removes the first product matching [productId].
      */
     fun removeProductById(productId: Int) {
         // TODO: remove product from _products by id
+        val product = _products.find {it.id == productId}
+        product?.let { _products.remove(it) }
     }
 
     /**
      * Returns the total price of all products in the order.
      */
     override fun calculateTotal(): Int {
         // TODO: sum the prices of all products
-        return 0
+        return _products.sumOf { it.price }
     }
 
     /**
@@ -41,6 +44,10 @@ class Order(
      */
     fun pay() {
         // TODO: throw if _products is empty, otherwise set status to Paid
+        if (_products.isEmpty()) {
+            throw IllegalStateException("Order is empty")
+        }
+        status = OrderStatus.Paid
     }
 
     /**
@@ -49,5 +56,7 @@ class Order(
      */
     fun cancel(reason: String?) {
         // TODO: set status to Cancelled with reason (default "Unknown reason" if null)
+        val cancel_reason = reason ?: "Unknown reason"
+        status = OrderStatus.Cancelled(cancel_reason)
     }
 }

src/main/kotlin/orders/OrderExtensions.kt

@@ -12,7 +12,19 @@ package orders
  */
 fun Order.applyDiscount(
     discountPercent: Int,
-    logger: ((String) -> Unit)? = null
+    logger: ((String) -> Unit)? = null //необязательный параметр
 ) {
     // TODO: apply discount to each product using extension + scoped functions
+    val allProducts = products.toList()
+
+    allProducts.forEach { product ->
+        val apdatedPrice = product.price * (100-discountPercent)/100
+
+        val apdatedProduct = product.copy(price = apdatedPrice)
+
+        removeProductById(product.id)
+        addProduct(apdatedProduct)
+
+        logger?.invoke("Product ${product.name} discounted from ${product.price} to ${apdatedPrice}")
+    }
 }

src/main/kotlin/orders/OrderProcessor.kt

@@ -9,5 +9,10 @@ package orders
  */
 fun processOrder(order: Order): String {
     // TODO: use when to return the appropriate string
-    return ""
+    return when(val order_status = order.status) {
+        is OrderStatus.Created -> "Order ${order.id} is new"
+
+        is OrderStatus.Paid -> "Order ${order.id} is paid"
+        is OrderStatus.Cancelled -> "Order ${order.id} is cancelled: ${order_status.reason}"
+    }
 }