lila/app/controllers/ForumController.scala

package controllers

import play.api.mvc.*

import lila.app.{ *, given }
import lila.core.id.{ ForumCategId, ForumTopicId, ForumTopicSlug }
import lila.forum.ForumTopic

private[controllers] trait ForumController:
  self: LilaController =>

  export env.forum.{ categApi, topicApi, topicRepo, postApi, forms, access }

  protected def CategGrantWrite[A <: Result](
      categId: ForumCategId,
      tryingToPostAsMod: Boolean = false
  )(a: => Fu[A])(using Context): Fu[Result] =
    access
      .isGrantedWrite(categId, tryingToPostAsMod)
      .flatMap:
        if _ then a
        else Forbidden("You cannot post to this category")

  protected def TopicGrantModBySlug[A <: Result](
      categId: ForumCategId,
      topicSlug: ForumTopicSlug
  )(a: => Fu[A])(using Context, Me): Fu[Result] =
    TopicGrantMod(categId)(topicRepo.byTree(categId, topicSlug))(a)

  protected def TopicGrantModById[A <: Result](categId: ForumCategId, topicId: ForumTopicId)(
      a: => Fu[A]
  )(using Context)(using me: Me): Fu[Result] =
    TopicGrantMod(categId)(topicRepo.forUser(me.some).byId(topicId))(a)

  private def TopicGrantMod[A <: Result](categId: ForumCategId)(
      getTopic: => Fu[Option[ForumTopic]]
  )(a: => Fu[A])(using Context)(using me: Me): Fu[Result] =
    access.isGrantedMod(categId).flatMap { granted =>
      if granted | isGranted(_.ModerateForum)
      then a
      else
        getTopic.flatMap: topic =>
          if topic.exists(_.isUblogAuthor(me)) then a
          else Forbidden("You cannot moderate this forum")
    }