the-algorithm/tweetypie/server/src/main/scala/com/twitter/tweetypie/handler/UpdatePossiblySensitiveTweetHandler.scala

package com.twitter.tweetypie
package handler

import com.twitter.tweetypie.store.UpdatePossiblySensitiveTweet
import com.twitter.tweetypie.thriftscala.UpdatePossiblySensitiveTweetRequest
import com.twitter.tweetypie.util.TweetLenses

object UpdatePossiblySensitiveTweetHandler {
  type Type = FutureArrow[UpdatePossiblySensitiveTweetRequest, Unit]

  def apply(
    tweetGetter: FutureArrow[TweetId, Tweet],
    userGetter: FutureArrow[UserId, User],
    updatePossiblySensitiveTweetStore: FutureEffect[UpdatePossiblySensitiveTweet.Event]
  ): Type =
    FutureArrow { request =>
      val nsfwAdminMutation = Mutation[Boolean](_ => request.nsfwAdmin).checkEq
      val nsfwUserMutation = Mutation[Boolean](_ => request.nsfwUser).checkEq
      val tweetMutation =
        TweetLenses.nsfwAdmin
          .mutation(nsfwAdminMutation)
          .also(TweetLenses.nsfwUser.mutation(nsfwUserMutation))

      for {
        originalTweet <- tweetGetter(request.tweetId)
        _ <- tweetMutation(originalTweet) match {
          case None => Future.Unit
          case Some(mutatedTweet) =>
            userGetter(getUserId(originalTweet))
              .map { user =>
                UpdatePossiblySensitiveTweet.Event(
                  tweet = mutatedTweet,
                  user = user,
                  timestamp = Time.now,
                  byUserId = request.byUserId,
                  nsfwAdminChange = nsfwAdminMutation(TweetLenses.nsfwAdmin.get(originalTweet)),
                  nsfwUserChange = nsfwUserMutation(TweetLenses.nsfwUser.get(originalTweet)),
                  note = request.note,
                  host = request.host
                )
              }
              .flatMap(updatePossiblySensitiveTweetStore)
        }
      } yield ()
    }
}