NTCoding

object Wiring {

  val recommendAFriend = useCases.RecommendAFriend(
    ValidateNewAccount.apply, FindUser.apply, CreateFriend.apply,
    PromoteToGoldStatus.apply
  )
  
}

NTCoding

object RecommendAFriend {
  type RecommendAFriendResult = Either[RecommendAFriendError, Seq[ReferralOutcome]]
  type RecommendAFriend = (UserId, NewAccountDetails) => Future[Either[RecommendAFriendError, Seq[ReferralOutcome]]]
  type ValidateNewAccount = NewAccountDetails => Option[RecommendAFriendError]
  type FindUser = UserId => Future[Option[User]]
  type CreateFriend = NewAccountDetails => Future[User]
  
  def apply(v: ValidateNewAccount, f: FindUser, c: CreateFriend, p: ReferralPolicy)
           (u: UserId, n: NewAccountDetails): Future[RecommendAFriendResult] = 
    v(n) map { err } getOrElse { f(u) flatMap {

NTCoding

object RecommendAFriend{
  type Validate = NewAccountDetails => Unit
  type FindCustomer = String => Option[User]
  type CreateCustomer = NewAccountDetails => User
  type ReferralPolicy = NewAccountDetails => User
  
  def apply(validate: Validate, findCustomer: FindCustomer, createCustomer: CreateCustomer, 
            referralPolicy: ReferralPolicy)
            (referrerId: Int, friendsAccountDetails: NewAcccountDetails) = {
    ...          

NTCoding

object RecommendAFriend{
  def apply(validate: NewAccountDetails => Unit, findCustomer: String => Option[User], 
            createCustomer: NewAccountDetails => User, referralPolicy: (User, User) => Future[Unit])
            (referrerId: Int, friendsAccountDetails: NewAcccountDetails) = {
    validate(friendsAccountDetails)
    
    val user = findCustomer(referrerId);
    val friend = createCustomer(friendsAccountDetails)
    referralPolicy(user, friend)
  }

NTCoding

var referrer = customerDirectory.Find(referrerId);

var friend = customerDirectory.Add(friendsAccountDetails);

referralPolicy.Apply(referrer, friend);

NTCoding

// construct
val recommendAFriend = RecommendAFriend(validator, customers, policy)
// invoke
recomendAFriend(referrerId, accountDetails)

NTCoding

object RecommendAFriend {
  def apply(validator: NewAccountValidator, customers: CustomerDirectory, policy: ReferralPolicy)
           (referrerId: Int, friendsAccountDetails: NewAccountDetails) = 
    ...
}

NTCoding

RecommendAFriend(customers, policy, referrerId, friendsAccountDetails)

NTCoding

object RecommendAFriend {
  def apply(customers: CustomerDirectory, policy: ReferralPolicy, referrerId: Int, friendsAccountDetails: NewAccountDetails) = 
    ...
}

NTCoding

public class RecommendAFriendService
{
    private INewAccountValidator validator;
    private ICustomerDirectory customerDirectory;
    private IReferralPolicy referralPolicy;
    
    public RecommendAFriendService(ICustomerDirectory customerDirectory, IReferralPolicy referralPolicy,
        INewAccountValidator validator)
    {
        this.validator = validator;