Find second minimum element from a list of integers in scala, complexity should be n (hence list can't be sorted).

SecondMinimum.scala

package com.recbuc.receipts

import scala.annotation.tailrec

object SecondMinimum {
  def main(args: Array[String]): Unit = {
    val regular  = List(5, 3, 2, 5, 1, 3, 1, -1, 2, -1, 5) // expected -1
    val sorted   = regular.sorted // expected -1
    val distinct = sorted.distinct //expected 1
    val reverse  = distinct.reverse //expected 1
    printSecondMin(secondMin(regular), "regular")
    printSecondMin(secondMin(sorted), "sorted")
    printSecondMin(secondMin(distinct), "distinct")
    printSecondMin(secondMin(reverse), "reverse")
  }

  def printSecondMin(result: Option[Int], listType: String): Unit = {
    println(s"$listType list second min is: " + result)
  }
 //note if we initialize first with list head and second with second head, we will not get expected results
  @tailrec
  def secondMin(list: List[Int], first: Option[Int] = None, second: Option[Int] = None): Option[Int] = {
    list match {
      case Nil => second
      case h :: t =>
        if (first.isEmpty)
          secondMin(t, Some(h), second)
        else if (first.exists(h < _)) //note if we say <= instead of < then second and first will alwasys be different
          secondMin(t, Some(h), first)
        else if (second.isEmpty || second.exists(h < _))
          secondMin(t, first, Some(h))
        else
          secondMin(t, first, second)
    }
  }
}