import scala.util.Random
import scala.math.BigDecimal

case class MakeModel(make: String, model: String)

case class T1(registration: String, make: String, model: String, engine_size: BigDecimal)

case class T2(make: String, model: String, engine_size: BigDecimal, sale_price: Double)

    val makeModelSet: Seq[MakeModel] = Seq(
      MakeModel("FORD", "FIESTA")
      , MakeModel("NISSAN", "QASHQAI")
      , MakeModel("HYUNDAI", "I20")
      , MakeModel("SUZUKI", "SWIFT")
      , MakeModel("MERCEDED_BENZ", "E CLASS")
      , MakeModel("VAUCHALL", "CORSA")
      , MakeModel("FIAT", "500")
      , MakeModel("SKODA", "OCTAVIA")
      , MakeModel("KIA", "RIO")
    )

    def randomMakeModel(): MakeModel = {
      val makeModelIndex = if (Random.nextBoolean()) 0 else Random.nextInt(makeModelSet.size)
      makeModelSet(makeModelIndex)
    }

    def randomEngineSize() = BigDecimal(s"1.${Random.nextInt(9)}")

    def randomRegistration(): String = s"${Random.alphanumeric.take(7).mkString("")}"

    def randomPrice() = 500 + Random.nextInt(5000)

    def randomT1(): T1 = {
      val makeModel = randomMakeModel()
      T1(randomRegistration(), makeModel.make, makeModel.model, randomEngineSize())
    }

    def randomT2(): T2 = {
      val makeModel = randomMakeModel()
      T2(makeModel.make, makeModel.model, randomEngineSize(), randomPrice())
    }

    val t1 = Seq.fill(10000)(randomT1()).toDS()

    val t2 = Seq.fill(100000)(randomT2()).toDS()