package controllers

import play.api.libs.json.{JsValue, Json}
import play.api.libs.typedmap.TypedKey
import play.api.mvc._

import scala.concurrent.{ExecutionContext, Future}

object SecuredActions {

  private val SteamIdAttr: TypedKey[String] = TypedKey("steamId")

  /** Steam ID текущего авторизованного пользователя (если он есть в запросе). */
  def steamId[A](request: Request[A]): Option[String] = request.attrs.get(SteamIdAttr)

  /** Steam ID текущего пользователя или "unknown", если его нет в запросе. */
  def steamIdOrUnknown[A](request: Request[A]): String = steamId(request).getOrElse("unknown")
}

/**
 * Simple session-based authentication via Steam ID.
 * Used to protect admin panel routes.
 */
trait SecuredActions {

  self: AbstractController =>

  private val SteamIdAttr: TypedKey[String] = SecuredActions.SteamIdAttr

  /** Wrapper that requires the user to be logged in with Steam. */
  def Secured: ActionBuilder[Request, AnyContent] =
    securedWith(controllerComponents.parsers.defaultBodyParser, apiStyle = false)

  /** Same as [[Secured]], but parses the request body as JSON. */
  def SecuredJson: ActionBuilder[Request, JsValue] =
    securedWith(controllerComponents.parsers.json, apiStyle = true)

  /** Same as [[Secured]], but answers AJAX calls with 401 JSON instead of a redirect. */
  def SecuredApi: ActionBuilder[Request, AnyContent] =
    securedWith(controllerComponents.parsers.defaultBodyParser, apiStyle = true)

  private def securedWith[A](bodyParser: BodyParser[A], apiStyle: Boolean): ActionBuilder[Request, A] =
    new ActionBuilder[Request, A] {

      override def parser: BodyParser[A] = bodyParser

      override def executionContext: ExecutionContext = controllerComponents.executionContext

      override def invokeBlock[B](request: Request[B], block: Request[B] => Future[Result]): Future[Result] =
        request.session.get("steamId") match {
          case Some(steamId) =>
            block(request.addAttr(SteamIdAttr, steamId))
          case None if apiStyle =>
            Future.successful(Unauthorized(Json.obj("error" -> "Please log in with Steam")))
          case None =>
            Future.successful(Redirect("/decider/admin/login").flashing("error" -> "Please log in with Steam"))
        }
    }
}