Mock implementation of createOrder action (use-case).

actions/actions.go

@@ -2,10 +2,7 @@ package actions
 
 import "orders/entity"
 
-type OrderCreator interface {
-	Create() *entity.Order
-}
-
+// Action interfaces to be implemented.
 type ProductAdder interface {
 	AddProduct(order *entity.Order, product *entity.Product)
 }

actions/createOrder.go

@@ -0,0 +1,38 @@
+package actions
+
+import (
+	"github.com/google/uuid"
+	"orders/entity"
+	"orders/repository"
+	"time"
+)
+
+// NewOrderRequest.
+type NewOrderRequest struct{}
+
+// CreateOrder action.
+type CreateOrder struct {
+	repo repository.OrderRepository
+}
+
+// Constructor.
+func NewCreateOrder(repo repository.OrderRepository) *CreateOrder {
+	return &CreateOrder{
+		repo: repo,
+	}
+}
+
+func (action *CreateOrder) Create(r NewOrderRequest) (*entity.Order, error) {
+	order := &entity.Order{
+		Uuid:      uuid.New().String(),
+		CreatedAt: time.Now(),
+	}
+
+	err := action.repo.Save(order)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return order, nil
+}

entity/order.go

@@ -3,8 +3,9 @@ package entity
 import "time"
 
 type Order struct {
-	customerId string
-	products   []Product
-	paymentId  string
-	createdAt  time.Time
+	Uuid       string
+	CustomerId string
+	Products   []Product
+	PaymentId  string
+	CreatedAt  time.Time
 }

go.mod

@@ -1,3 +1,8 @@
 module orders
 
 go 1.20
+
+require (
+	github.com/google/uuid v1.3.0
+	github.com/gorilla/mux v1.8.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=

main.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"orders/actions"
+	"orders/repository"
+	"orders/rest"
+	"time"
+
+	"github.com/gorilla/mux"
+)
+
+func main() {
+	// Entity repository.
+	repo := repository.NewInMemoryOrderRepo()
+
+	// Rest json responder.
+	respndr:=rest.NewResponder("2006-01-02 15:04:05")
+
+	// New order controller.
+	cntrlr := rest.NewCreateOrder(actions.NewCreateOrder(repo), respndr)
+
+	// Router and server.
+	r := mux.NewRouter()
+	r.HandleFunc("/create", cntrlr.Create)
+
+	srv := &http.Server{
+		Handler: r,
+		Addr:    "127.0.0.1:8081",
+		WriteTimeout: 15 * time.Second,
+		ReadTimeout:  15 * time.Second,
+	}
+
+	log.Fatal(srv.ListenAndServe())
+
+}

repository/order.go

@@ -3,7 +3,33 @@ package repository
 import "orders/entity"
 
 // Persists Order to db, filesystem, etc.
-type orderRepository interface {
-	Save(order entity.Order)
+type OrderRepository interface {
+	Save(order *entity.Order) error
 	FindById(orderId string) *entity.Order
 }
+
+// InMemoryOrderRepo.
+type InMemoryOrderRepo struct {
+	orders map[string]*entity.Order
+}
+
+// Constructor.
+func NewInMemoryOrderRepo() *InMemoryOrderRepo {
+	return &InMemoryOrderRepo{
+		orders: make(map[string]*entity.Order),
+	}
+}
+
+func (repo *InMemoryOrderRepo) Save(order *entity.Order) error {
+	repo.orders[order.Uuid] = order
+	return nil
+}
+
+func (repo *InMemoryOrderRepo) FindById(orderId string) *entity.Order {
+	for _, order := range repo.orders {
+		if order.Uuid == orderId {
+			return order
+		}
+	}
+	return nil
+}

rest/createOrder.go

@@ -0,0 +1,30 @@
+package rest
+
+import (
+	"net/http"
+	"orders/actions"
+)
+
+// Create order controller.
+type CreateOrder struct {
+	action *actions.CreateOrder
+	rspndr *Responder
+}
+
+// Constructor.
+func NewCreateOrder(action *actions.CreateOrder, rspndr *Responder) *CreateOrder {
+	return &CreateOrder{
+		action: action,
+		rspndr: rspndr,
+	}
+}
+
+func (c *CreateOrder) Create(w http.ResponseWriter, r *http.Request) {
+	order, err := c.action.Create(actions.NewOrderRequest{})
+
+	if err != nil {
+		c.rspndr.Error(w, http.StatusInternalServerError, err.Error())
+	}
+
+	c.rspndr.Success(w, order)
+}

rest/responder.go

@@ -0,0 +1,52 @@
+package rest
+
+import (
+	"encoding/json"
+	"net/http"
+	"time"
+)
+
+// JSON response object.
+type Response struct {
+	Date    string      `json:"date"`
+	Message string      `json:"message"`
+	Payload interface{} `json:"payload"`
+}
+
+func NewResponse() *Response {
+	return &Response{}
+}
+
+// Responder.
+type Responder struct {
+	dateFormat string
+}
+
+func NewResponder(dateFormat string) *Responder {
+	return &Responder{dateFormat: dateFormat}
+}
+
+func (rspndr *Responder) Error(w http.ResponseWriter, statusCode int, message string) {
+	// Build json response.
+	r := NewResponse()
+	r.Date = time.Now().Format(rspndr.dateFormat)
+	r.Message = message
+
+	// Send response.
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+	json.NewEncoder(w).Encode(r)
+}
+
+func (rspndr *Responder) Success(w http.ResponseWriter, payload interface{}) {
+	// Build json response.
+	r := NewResponse()
+	r.Date = time.Now().Format(rspndr.dateFormat)
+	r.Message = "ok"
+	r.Payload = payload
+
+	// Send response.
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(r)
+}