TransactionSpec

import org.specs2.mutable.Specification

class TransactionSpec extends Specification {

  val priceList: List[Item] = List(
    Item("A", 50, Some(SpecialOffer(3, 130))),
    Item("B", 30, Some(SpecialOffer(2, 45))),
    Item("C", 20),
    Item("D", 15)
  )

  val transaction = Transaction(priceList)

  "Given a valid price list, getting the total for a series of items" should {
    "calculate a single item price correctly" >> {
      val total = transaction.calculateTotal("B")
      total must beEqualTo(30)
    }

    "calculate a series of individual item prices correctly" >> {
      val total = transaction.calculateTotal("A,B,C,D")
      total must beEqualTo(115)
    }

    "calculate bulk discounts correctly" >> {
      val total = transaction.calculateTotal("A,A,A,B,B")
      total must beEqualTo(175)
    }

    "calculate individual items and bulk discounts correctly" >> {
      val total = transaction.calculateTotal("A,A,A,B,C,D")
      total must beEqualTo(195)
    }

    "throw an Item Not Found exception if an invalid SKU is entered" >> {
      transaction.calculateTotal("A,E") must throwAn[ItemNotFoundException]
    }
  }
}