package com.apptentive.profile.routes

import java.util.UUID
import java.util.UUID.fromString

import akka.http.scaladsl.server.Directive1
import akka.http.scaladsl.server.Directives._
import com.apptentive.profile.routes.Paging._

import scala.util._

trait Pagination {

  def extractPaging: Directive1[Paging] = {
    parameterMap.flatMap { params =>
      // extraction
      val size        = Try(params.get("page_size").map(_.toInt).get)
      val startsAfter = Try(params.get("starts_after").map(fromString))

      (size, startsAfter) match {
        case (Failure(_), _) | (_, Failure(_)) | (Success(s), _) if !ValidPageSizes.contains(s) =>
          reject
        case (_, _) =>
          provide(Paging(startsAfter.getOrElse(None), size.getOrElse(DefaultPageSize)))
      }
    }
  }

}

object Paging {
  val DefaultPageSize: Int  = 100
  val ValidPageSizes: Range = 1 to 4000
}

case class Paging(startsAfter: Option[UUID] = None, size: Int = DefaultPageSize)