def fetchCandidates()

in cr-mixer/server/src/main/scala/com/twitter/cr_mixer/candidate_generation/AdsCandidateSourcesRouter.scala [87:248]
149 lines of code
13 McCabe index (conditional complexity)

  def fetchCandidates(
    requestUserId: UserId,
    sourceSignals: Set[SourceInfo],
    realGraphSeeds: Map[UserId, Double],
    params: configapi.Params
  ): Future[Seq[Seq[InitialAdsCandidate]]] = {

    val simClustersANN1ConfigId = params(SimClustersANNParams.SimClustersANN1ConfigId)

    val tweetBasedSANNMinScore = params(
      TweetBasedCandidateGenerationParams.SimClustersMinScoreParam)
    val tweetBasedSANN1Candidates =
      if (params(TweetBasedCandidateGenerationParams.EnableSimClustersANN1Param)) {
        Future.collect(
          CandidateSourcesRouter.getTweetBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getSimClustersANNCandidates(
              requestUserId,
              Some(sourceInfo),
              params,
              simClustersANN1ConfigId,
              tweetBasedSANNMinScore)
          })
      } else Future.value(Seq.empty)

    val simClustersANN2ConfigId = params(SimClustersANNParams.SimClustersANN2ConfigId)
    val tweetBasedSANN2Candidates =
      if (params(TweetBasedCandidateGenerationParams.EnableSimClustersANN2Param)) {
        Future.collect(
          CandidateSourcesRouter.getTweetBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getSimClustersANNCandidates(
              requestUserId,
              Some(sourceInfo),
              params,
              simClustersANN2ConfigId,
              tweetBasedSANNMinScore)
          })
      } else Future.value(Seq.empty)

    val tweetBasedUagCandidates =
      if (params(TweetBasedCandidateGenerationParams.EnableUAGParam)) {
        Future.collect(
          CandidateSourcesRouter.getTweetBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getTweetBasedUserAdGraphCandidates(Some(sourceInfo), params)
          })
      } else Future.value(Seq.empty)

    val realGraphInNetworkBasedUagCandidates =
      if (params(ConsumersBasedUserAdGraphParams.EnableSourceParam)) {
        getRealGraphConsumersBasedUserAdGraphCandidates(realGraphSeeds, params).map(Seq(_))
      } else Future.value(Seq.empty)

    val producerBasedUagCandidates =
      if (params(ProducerBasedCandidateGenerationParams.EnableUAGParam)) {
        Future.collect(
          CandidateSourcesRouter.getProducerBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getProducerBasedUserAdGraphCandidates(Some(sourceInfo), params)
          })
      } else Future.value(Seq.empty)

    val tweetBasedTwhinAdsCandidates =
      if (params(TweetBasedCandidateGenerationParams.EnableTwHINParam)) {
        Future.collect(
          CandidateSourcesRouter.getTweetBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getTwHINAdsCandidates(
              tweetBasedTwHINANNSimilarityEngine,
              SimilarityEngineType.TweetBasedTwHINANN,
              requestUserId,
              Some(sourceInfo),
              ModelConfig.DebuggerDemo)
          })
      } else Future.value(Seq.empty)

    val producerBasedSANNMinScore = params(
      ProducerBasedCandidateGenerationParams.SimClustersMinScoreParam)
    val producerBasedSANN1Candidates =
      if (params(ProducerBasedCandidateGenerationParams.EnableSimClustersANN1Param)) {
        Future.collect(
          CandidateSourcesRouter.getProducerBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getSimClustersANNCandidates(
              requestUserId,
              Some(sourceInfo),
              params,
              simClustersANN1ConfigId,
              producerBasedSANNMinScore)
          })
      } else Future.value(Seq.empty)
    val producerBasedSANN2Candidates =
      if (params(ProducerBasedCandidateGenerationParams.EnableSimClustersANN2Param)) {
        Future.collect(
          CandidateSourcesRouter.getProducerBasedSourceInfo(sourceSignals).toSeq.map { sourceInfo =>
            getSimClustersANNCandidates(
              requestUserId,
              Some(sourceInfo),
              params,
              simClustersANN2ConfigId,
              producerBasedSANNMinScore)
          })
      } else Future.value(Seq.empty)

    val interestedInMinScore = params(InterestedInParams.MinScoreParam)
    val interestedInSANN1Candidates = if (params(InterestedInParams.EnableSimClustersANN1Param)) {
      getSimClustersANNCandidates(
        requestUserId,
        None,
        params,
        simClustersANN1ConfigId,
        interestedInMinScore).map(Seq(_))
    } else Future.value(Seq.empty)

    val interestedInSANN2Candidates = if (params(InterestedInParams.EnableSimClustersANN2Param)) {
      getSimClustersANNCandidates(
        requestUserId,
        None,
        params,
        simClustersANN2ConfigId,
        interestedInMinScore).map(Seq(_))
    } else Future.value(Seq.empty)

    val consumerTwHINAdsCandidates =
      if (params(ConsumerEmbeddingBasedCandidateGenerationParams.EnableTwHINParam)) {
        getTwHINAdsCandidates(
          consumerTwHINANNSimilarityEngine,
          SimilarityEngineType.ConsumerEmbeddingBasedTwHINANN,
          requestUserId,
          None,
          ModelConfig.DebuggerDemo).map(Seq(_))
      } else Future.value(Seq.empty)

    val consumerBasedWalsCandidates =
      if (params(
          ConsumerBasedWalsParams.EnableSourceParam
        )) {
        getConsumerBasedWalsCandidates(sourceSignals, params)
      }.map {
        Seq(_)
      }
      else Future.value(Seq.empty)

    Future
      .collect(Seq(
        tweetBasedSANN1Candidates,
        tweetBasedSANN2Candidates,
        tweetBasedUagCandidates,
        tweetBasedTwhinAdsCandidates,
        producerBasedUagCandidates,
        producerBasedSANN1Candidates,
        producerBasedSANN2Candidates,
        realGraphInNetworkBasedUagCandidates,
        interestedInSANN1Candidates,
        interestedInSANN2Candidates,
        consumerTwHINAdsCandidates,
        consumerBasedWalsCandidates,
      )).map(_.flatten).map { tweetsWithCGInfoSeq =>
        Future.collect(
          tweetsWithCGInfoSeq.map(candidates => convertToInitialCandidates(candidates, stats)))
      }.flatten.map { candidatesLists =>
        val result = candidatesLists.filter(_.nonEmpty)
        stats.stat("numOfSequences").add(result.size)
        stats.stat("flattenCandidatesWithDup").add(result.flatten.size)
        result
      }
  }