/**
    * Validate password strength.
    *
    * {{{
    * case class Model(password: String)
    *
    * val form: Form[Model] = {
    *   import play.api.data.Forms._
    *
    * Form(
    *     mapping(
    *       "password" -> password
    *     )(Model.apply)(Model.unapply)
    *   )
    * }
    * }}}
    */
  val password: Mapping[String] = text(minLength = 8, maxLength = 32).verifying(
    "Password must contain at least 3 of the following: capital letter, lowercase letter, number, or symbol",
    value => {
      val codePoints: Seq[Int] = value.codePoints().toArray

      val categorizers: List[Int => Boolean] = List(
        (codePoint: Int) => Character.isUpperCase(codePoint),
        (codePoint: Int) => Character.isLowerCase(codePoint),
        (codePoint: Int) => Character.isDigit(codePoint),
        (codePoint: Int) => !Character.isLetterOrDigit(codePoint)
      )

      val count = categorizers.foldLeft(0) { (sum, categorizer) =>
        sum + (if (codePoints.exists(categorizer)) 1 else 0)
      }

      count >= 3
    }
  )