import ballerina/http; import ballerina/mime; import ballerina/random; configurable int port = 8080; enum CakeKind { BUTTER_CAKE = "Butter Cake", CHOCOLATE_CAKE = "Chocolate Cake", TRES_LECHES = "Tres Leches" } const map MENU = { "Butter Cake": 15, "Chocolate Cake": 20, "Tres Leches": 25 }; enum OrderStatus { PENDING = "pending", IN_PROGRESS = "in progress", COMPLETED = "completed" } type OrderDetail record {| CakeKind item; int quantity; |}; type Order record {| string username; OrderDetail[] order_items; |}; type OrderUpdate record {| OrderDetail[] order_items; |}; map orders = {}; map orderStatus = {}; service on new http:Listener(port) { resource function get menu() returns MENU => MENU; resource function post 'order(@http:Payload Order & readonly newOrder) returns http:Created|http:BadRequest|error { if newOrder.username == "" { return {}; } int|http:BadRequest total = computeSum(newOrder.order_items); if total is http:BadRequest { return total; } string orderId = check generateOrderId(); orders[orderId] = newOrder; orderStatus[orderId] = PENDING; return { body: {order_id: orderId, total}, mediaType: mime:APPLICATION_JSON }; } resource function get 'order/[string orderId]() returns http:Ok|http:NotFound { lock { if !orderStatus.hasKey(orderId) { return {}; } return { body: {order_id: orderId, status: orderStatus.get(orderId)}, mediaType: mime:APPLICATION_JSON }; } } resource function put 'order/[string orderId](@http:Payload OrderUpdate & readonly updatedOrder) returns http:Ok|http:BadRequest|http:Forbidden|http:NotFound { final OrderDetail[] & readonly orderItems; final int total; if !orders.hasKey(orderId) { return {}; } if orderStatus.get(orderId) != PENDING { return {}; } orderItems = updatedOrder.order_items; int|(http:BadRequest & readonly) sumRes = computeSum(orderItems); if sumRes is http:BadRequest { return sumRes; } _ = orderStatus.remove(orderId); total = sumRes; string username; Order existingOrder = orders.remove(orderId); username = existingOrder.username; orders[orderId] = {username, order_items: orderItems}; orderStatus[orderId] = PENDING; return { body: {order_id: orderId, total}, mediaType: mime:APPLICATION_JSON }; } resource function delete 'order/[string orderId]() returns http:Ok|http:Forbidden|http:NotFound { lock { if !orderStatus.hasKey(orderId) { return {}; } if orderStatus.get(orderId) != PENDING { return {}; } _ = orderStatus.remove(orderId); } _ = orders.remove(orderId); return {}; } } function generateOrderId() returns string|error { while true { string orderId = (check random:createIntInRange(1, 100)).toString(); if !orders.hasKey(orderId) { return orderId; } } } function computeSum(OrderDetail[] items) returns int|(http:BadRequest & readonly) { if items.length() == 0 { return {}; } int total = 0; string[] cakeTypes = MENU.keys(); foreach OrderDetail {item, quantity} in items { int? index = cakeTypes.indexOf(item); if quantity < 1 || index is () { return {}; } _ = cakeTypes.remove(index); total += MENU.get(item) * quantity; } return total; }