feat: api complete

src/order_taking/place_order/api.gleam

@@ -6,10 +6,13 @@
 // 3) The output is turned into a DTO which is turned into a HttpResponse
 // ======================================================
 
+import gleam/http/request
 import gleam/http/response
 import gleam/json
 import gleam/list
+import gleam/result
 import order_taking/common/simple_types/price
+import order_taking/place_order/dto/order_form_dto
 import order_taking/place_order/dto/place_order_error_dto
 import order_taking/place_order/dto/place_order_event_dto
 import order_taking/place_order/implementation
@@ -35,12 +38,12 @@ pub fn check_product_exists(_product_code) {
 pub fn check_address_exists(unvalidated_address) {
   let checked_address = implementation.CheckedAddress(unvalidated_address)
 
-  checked_address
+  Ok(checked_address)
 }
 
 /// dummy implementation
 pub fn get_product_price(_product_code) {
-  price.from_int(1)
+  result.unwrap(price.from_int(1), price.zero())
 }
 
 /// dummy implementation
@@ -94,28 +97,52 @@ pub fn workflow_result_to_http_reponse(result) -> response.Response(String) {
     }
   }
 }
-// let placeOrderApi : PlaceOrderApi =
-//     fun request ->
-//         // following the approach in "A Complete Serialization Pipeline" in chapter 11
-
-//         // start with a string
-//         let orderFormJson = request.Body
-//         let orderForm = deserializeJson<OrderFormDto>(orderFormJson)
-//         // convert to domain object
-//         let unvalidatedOrder = orderForm |> OrderFormDto.toUnvalidatedOrder
-
-//         // setup the dependencies. See "Injecting Dependencies" in chapter 9
-//         let workflow =
-//             Implementation.placeOrder
-//                 checkProductExists // dependency
-//                 checkAddressExists // dependency
-//                 getProductPrice    // dependency
-//                 createOrderAcknowledgmentLetter  // dependency
-//                 sendOrderAcknowledgment // dependency
-
-//         // now we are in the pure domain
-//         let asyncResult = workflow unvalidatedOrder
-
-//         // now convert from the pure domain back to a HttpResponse
-//         asyncResult
-//         |> Async.map (workflowResultToHttpReponse)
+
+pub fn place_order_api(
+  request: request.Request(String),
+) -> response.Response(String) {
+  // following the approach in "A Complete Serialization Pipeline" in chapter 11
+
+  // start with a string
+  let order_form_json = request.body
+  let order_form =
+    json.decode(from: order_form_json, using: order_form_dto.decoder())
+
+  case order_form {
+    Ok(order_form) -> {
+      // convert to domain object
+      let unvalidated_order = order_form |> order_form_dto.to_unvalidated_order
+
+      // setup the dependencies. See "Injecting Dependencies" in chapter 9
+      let workflow =
+        implementation.place_order(
+          check_product_exists,
+          // dependency
+          check_address_exists,
+          // dependency
+          get_product_price,
+          // dependency
+          create_order_acknowledgment_letter,
+          // dependency
+          send_order_acknowledgment,
+          // dependency
+        )
+
+      // now we are in the pure domain
+      let result = workflow(unvalidated_order)
+
+      // now convert from the pure domain back to a HttpResponse
+      result
+      |> workflow_result_to_http_reponse
+    }
+    Error(_json_error) -> {
+      let response =
+        response.Response(
+          status: 403,
+          body: "JSON deserialisation error",
+          headers: [],
+        )
+      response
+    }
+  }
+}

src/order_taking/place_order/dto/address_dto.gleam

@@ -19,7 +19,7 @@ pub type AddressDto {
 }
 
 /// For deserialising
-pub fn from_json(json_string: String) -> Result(AddressDto, json.DecodeError) {
+pub fn decoder() {
   let decoder =
     dynamic.decode6(
       AddressDto,
@@ -31,7 +31,7 @@ pub fn from_json(json_string: String) -> Result(AddressDto, json.DecodeError) {
       dynamic.field("zip_code", of: dynamic.string),
     )
 
-  json.decode(from: json_string, using: decoder)
+  decoder
 }
 
 /// For serialising

src/order_taking/place_order/dto/customer_info_dto.gleam

@@ -15,9 +15,7 @@ pub type CustomerInfoDto {
 }
 
 /// For deserialising
-pub fn from_json(
-  json_string: String,
-) -> Result(CustomerInfoDto, json.DecodeError) {
+pub fn decoder(json_string: String) {
   let decoder =
     dynamic.decode3(
       CustomerInfoDto,
@@ -26,7 +24,7 @@ pub fn from_json(
       dynamic.field("email_address", of: dynamic.string),
     )
 
-  json.decode(from: json_string, using: decoder)
+  decoder
 }
 
 /// For serialising

src/order_taking/place_order/dto/order_form_dto.gleam

@@ -1,19 +1,35 @@
+import gleam/dynamic
 import gleam/list
 import order_taking/common/public_types
-import order_taking/place_order/dto/address_dto.{type AddressDto}
-import order_taking/place_order/dto/customer_info_dto.{type CustomerInfoDto}
-import order_taking/place_order/dto/order_line_dto.{type OrderFormLineDto}
+import order_taking/place_order/dto/address_dto
+import order_taking/place_order/dto/customer_info_dto
+import order_taking/place_order/dto/order_line_dto
 
 pub type OrderFormDto {
   OrderFormDto(
     order_id: String,
-    customer_info: CustomerInfoDto,
-    shipping_address: AddressDto,
-    billing_address: AddressDto,
-    lines: List(OrderFormLineDto),
+    customer_info: customer_info_dto.CustomerInfoDto,
+    shipping_address: address_dto.AddressDto,
+    billing_address: address_dto.AddressDto,
+    lines: List(order_line_dto.OrderFormLineDto),
   )
 }
 
+/// For deserialising
+pub fn decoder() {
+  let decoder =
+    dynamic.decode5(
+      OrderFormDto,
+      dynamic.field("order_id", of: dynamic.string),
+      dynamic.field("customer_info", of: customer_info_dto.decoder()),
+      dynamic.field("shipping_address", of: address_dto.decoder()),
+      dynamic.field("billing_address", of: address_dto.decoder()),
+      dynamic.field("lines", of: dynamic.list(order_line_dto.decoder())),
+    )
+
+  decoder
+}
+
 /// Convert the OrderForm into a UnvalidatedOrder
 /// This always succeeds because there is no validation.
 pub fn to_unvalidated_order(dto: OrderFormDto) -> public_types.UnvalidatedOrder {

src/order_taking/place_order/dto/order_line_dto.gleam

@@ -12,9 +12,7 @@ pub type OrderFormLineDto {
 }
 
 /// For deserialising
-pub fn from_json(
-  json_string: String,
-) -> Result(OrderFormLineDto, json.DecodeError) {
+pub fn decoder() {
   let decoder =
     dynamic.decode3(
       OrderFormLineDto,
@@ -23,7 +21,7 @@ pub fn from_json(
       dynamic.field("quantity", of: dynamic.string),
     )
 
-  json.decode(from: json_string, using: decoder)
+  decoder
 }
 
 /// For serialising