package com.twitter.frigate.pushservice.adaptor

import com.twitter.finagle.stats.Counter
import com.twitter.finagle.stats.Stat
import com.twitter.finagle.stats.StatsReceiver
import com.twitter.frigate.common.base.CandidateSource
import com.twitter.frigate.common.base.CandidateSourceEligible
import com.twitter.frigate.common.base.TweetCandidate
import com.twitter.frigate.common.predicate.CommonOutNetworkTweetCandidatesSourcePredicates.filterOutReplyTweet
import com.twitter.frigate.pushservice.model.PushTypes.RawCandidate
import com.twitter.frigate.pushservice.model.PushTypes.Target
import com.twitter.frigate.pushservice.model.PushTypes
import com.twitter.frigate.pushservice.params.PopGeoTweetVersion
import com.twitter.frigate.pushservice.params.PushParams
import com.twitter.frigate.pushservice.params.TopTweetsForGeoCombination
import com.twitter.frigate.pushservice.params.TopTweetsForGeoRankingFunction
import com.twitter.frigate.pushservice.params.{PushFeatureSwitchParams => FS}
import com.twitter.frigate.pushservice.predicate.DiscoverTwitterPredicate
import com.twitter.frigate.pushservice.predicate.TargetPredicates
import com.twitter.frigate.pushservice.util.MediaCRT
import com.twitter.frigate.pushservice.util.PushAdaptorUtil
import com.twitter.frigate.pushservice.util.PushDeviceUtil
import com.twitter.frigate.thriftscala.CommonRecommendationType
import com.twitter.geoduck.common.thriftscala.{Location => GeoLocation}
import com.twitter.geoduck.service.thriftscala.LocationResponse
import com.twitter.gizmoduck.thriftscala.UserType
import com.twitter.hermit.pop_geo.thriftscala.PopTweetsInPlace
import com.twitter.recommendation.interests.discovery.core.model.InterestDomain
import com.twitter.stitch.tweetypie.TweetyPie.TweetyPieResult
import com.twitter.storehaus.FutureOps
import com.twitter.storehaus.ReadableStore
import com.twitter.util.Future
import com.twitter.util.Time
import scala.collection.Map

case class PlaceTweetScore(place: String, tweetId: Long, score: Double) {
  def toTweetScore: (Long, Double) = (tweetId, score)
}
case class TopTweetsByGeoAdaptor(
  geoduckStoreV2: ReadableStore[Long, LocationResponse],
  softUserGeoLocationStore: ReadableStore[Long, GeoLocation],
  topTweetsByGeoStore: ReadableStore[InterestDomain[String], Map[String, List[(Long, Double)]]],
  topTweetsByGeoStoreV2: ReadableStore[String, PopTweetsInPlace],
  tweetyPieStore: ReadableStore[Long, TweetyPieResult],
  tweetyPieStoreNoVF: ReadableStore[Long, TweetyPieResult],
  globalStats: StatsReceiver)
    extends CandidateSource[Target, RawCandidate]
    with CandidateSourceEligible[Target, RawCandidate] {

  override def name: String = this.getClass.getSimpleName

  private[this] val stats = globalStats.scope("TopTweetsByGeoAdaptor")
  private[this] val noGeohashUserCounter: Counter = stats.counter("users_with_no_geohash_counter")
  private[this] val incomingRequestCounter: Counter = stats.counter("incoming_request_counter")
  private[this] val incomingLoggedOutRequestCounter: Counter =
    stats.counter("incoming_logged_out_request_counter")
  private[this] val loggedOutRawCandidatesCounter =
    stats.counter("logged_out_raw_candidates_counter")
  private[this] val emptyLoggedOutRawCandidatesCounter =
    stats.counter("logged_out_empty_raw_candidates")
  private[this] val outputTopTweetsByGeoCounter: Stat =
    stats.stat("output_top_tweets_by_geo_counter")
  private[this] val loggedOutPopByGeoV2CandidatesCounter: Counter =
    stats.counter("logged_out_pop_by_geo_candidates")
  private[this] val dormantUsersSince14DaysCounter: Counter =
    stats.counter("dormant_user_since_14_days_counter")
  private[this] val dormantUsersSince30DaysCounter: Counter =
    stats.counter("dormant_user_since_30_days_counter")
  private[this] val nonDormantUsersSince14DaysCounter: Counter =
    stats.counter("non_dormant_user_since_14_days_counter")
  private[this] val topTweetsByGeoTake100Counter: Counter =
    stats.counter("top_tweets_by_geo_take_100_counter")
  private[this] val combinationRequestsCounter =
    stats.scope("combination_method_request_counter")
  private[this] val popGeoTweetVersionCounter =
    stats.scope("popgeo_tweet_version_counter")
  private[this] val nonReplyTweetsCounter = stats.counter("non_reply_tweets")

  val MaxGeoHashSize = 4

  private def constructKeys(
    geohash: Option[String],
    accountCountryCode: Option[String],
    keyLengths: Seq[Int],
    version: PopGeoTweetVersion.Value
  ): Set[String] = {
    val geohashKeys = geohash match {
      case Some(hash) => keyLengths.map { version + "_geohash_" + hash.take(_) }
      case _ => Seq.empty
    }

    val accountCountryCodeKeys =
      accountCountryCode.toSeq.map(version + "_country_" + _.toUpperCase)
    (geohashKeys ++ accountCountryCodeKeys).toSet
  }

  def convertToPlaceTweetScore(
    popTweetsInPlace: Seq[PopTweetsInPlace]
  ): Seq[PlaceTweetScore] = {
    popTweetsInPlace.flatMap {
      case p =>
        p.popTweets.map {
          case popTweet => PlaceTweetScore(p.place, popTweet.tweetId, popTweet.score)
        }
    }
  }

  def sortGeoHashTweets(
    placeTweetScores: Seq[PlaceTweetScore],
    rankingFunction: TopTweetsForGeoRankingFunction.Value
  ): Seq[PlaceTweetScore] = {
    rankingFunction match {
      case TopTweetsForGeoRankingFunction.Score =>
        placeTweetScores.sortBy(_.score)(Ordering[Double].reverse)
      case TopTweetsForGeoRankingFunction.GeohashLengthAndThenScore =>
        placeTweetScores
          .sortBy(row => (row.place.length, row.score))(Ordering[(Int, Double)].reverse)
    }
  }

  def getResultsForLambdaStore(
    inputTarget: Target,
    geohash: Option[String],
    store: ReadableStore[String, PopTweetsInPlace],
    topk: Int,
    version: PopGeoTweetVersion.Value
  ): Future[Seq[(Long, Double)]] = {
    inputTarget.accountCountryCode.flatMap { countryCode =>
      val keys = {
        if (inputTarget.params(FS.EnableCountryCodeBackoffTopTweetsByGeo))
          constructKeys(geohash, countryCode, inputTarget.params(FS.GeoHashLengthList), version)
        else
          constructKeys(geohash, None, inputTarget.params(FS.GeoHashLengthList), version)
      }
      FutureOps
        .mapCollect(store.multiGet(keys)).map {
          case geohashTweetMap =>
            val popTweets =
              geohashTweetMap.values.flatten.toSeq
            val results = sortGeoHashTweets(
              convertToPlaceTweetScore(popTweets),
              inputTarget.params(FS.RankingFunctionForTopTweetsByGeo))
              .map(_.toTweetScore).take(topk)
            results
        }
    }
  }

  def getPopGeoTweetsForLoggedOutUsers(
    inputTarget: Target,
    store: ReadableStore[String, PopTweetsInPlace]
  ): Future[Seq[(Long, Double)]] = {
    inputTarget.countryCode.flatMap { countryCode =>
      val keys = constructKeys(None, countryCode, Seq(4), PopGeoTweetVersion.Prod)
      FutureOps.mapCollect(store.multiGet(keys)).map {
        case tweetMap =>
          val tweets = tweetMap.values.flatten.toSeq
          loggedOutPopByGeoV2CandidatesCounter.incr(tweets.size)
          val popTweets = sortGeoHashTweets(
            convertToPlaceTweetScore(tweets),
            TopTweetsForGeoRankingFunction.Score).map(_.toTweetScore)
          popTweets
      }
    }
  }

  def getRankedTweets(
    inputTarget: Target,
    geohash: Option[String]
  ): Future[Seq[(Long, Double)]] = {
    val MaxTopTweetsByGeoCandidatesToTake =
      inputTarget.params(FS.MaxTopTweetsByGeoCandidatesToTake)
    val scoringFn: String = inputTarget.params(FS.ScoringFuncForTopTweetsByGeo)
    val combinationMethod = inputTarget.params(FS.TopTweetsByGeoCombinationParam)
    val popGeoTweetVersion = inputTarget.params(FS.PopGeoTweetVersionParam)

    inputTarget.isHeavyUserState.map { isHeavyUser =>
      stats
        .scope(combinationMethod.toString).scope(popGeoTweetVersion.toString).scope(
          "IsHeavyUser_" + isHeavyUser.toString).counter().incr()
    }
    combinationRequestsCounter.scope(combinationMethod.toString).counter().incr()
    popGeoTweetVersionCounter.scope(popGeoTweetVersion.toString).counter().incr()
    lazy val geoStoreResults = if (geohash.isDefined) {
      val hash = geohash.get.take(MaxGeoHashSize)
      topTweetsByGeoStore
        .get(
          InterestDomain[String](hash)
        )
        .map {
          case Some(scoringFnToTweetsMapOpt) =>
            val tweetsWithScore = scoringFnToTweetsMapOpt
              .getOrElse(scoringFn, List.empty)
            val sortedResults = sortGeoHashTweets(
              tweetsWithScore.map {
                case (tweetId, score) => PlaceTweetScore(hash, tweetId, score)
              },
              TopTweetsForGeoRankingFunction.Score
            ).map(_.toTweetScore).take(
                MaxTopTweetsByGeoCandidatesToTake
              )
            sortedResults
          case _ => Seq.empty
        }
    } else Future.value(Seq.empty)
    lazy val versionPopGeoTweetResults =
      getResultsForLambdaStore(
        inputTarget,
        geohash,
        topTweetsByGeoStoreV2,
        MaxTopTweetsByGeoCandidatesToTake,
        popGeoTweetVersion
      )
    combinationMethod match {
      case TopTweetsForGeoCombination.Default => geoStoreResults
      case TopTweetsForGeoCombination.AccountsTweetFavAsBackfill =>
        Future.join(geoStoreResults, versionPopGeoTweetResults).map {
          case (geoStoreTweets, versionPopGeoTweets) =>
            (geoStoreTweets ++ versionPopGeoTweets).take(MaxTopTweetsByGeoCandidatesToTake)
        }
      case TopTweetsForGeoCombination.AccountsTweetFavIntermixed =>
        Future.join(geoStoreResults, versionPopGeoTweetResults).map {
          case (geoStoreTweets, versionPopGeoTweets) =>
            CandidateSource.interleaveSeqs(Seq(geoStoreTweets, versionPopGeoTweets))
        }
    }
  }

  override def get(inputTarget: Target): Future[Option[Seq[RawCandidate]]] = {
    if (inputTarget.isLoggedOutUser) {
      incomingLoggedOutRequestCounter.incr()
      val rankedTweets = getPopGeoTweetsForLoggedOutUsers(inputTarget, topTweetsByGeoStoreV2)
      val rawCandidates = {
        rankedTweets.map { rt =>
          FutureOps
            .mapCollect(
              tweetyPieStore
                .multiGet(rt.map { case (tweetId, _) => tweetId }.toSet))
            .map { tweetyPieResultMap =>
              val results = buildTopTweetsByGeoRawCandidates(
                inputTarget,
                None,
                tweetyPieResultMap
              )
              if (results.isEmpty) {
                emptyLoggedOutRawCandidatesCounter.incr()
              }
              loggedOutRawCandidatesCounter.incr(results.size)
              Some(results)
            }
        }.flatten
      }
      rawCandidates
    } else {
      incomingRequestCounter.incr()
      getGeoHashForUsers(inputTarget).flatMap { geohash =>
        if (geohash.isEmpty) noGeohashUserCounter.incr()
        getRankedTweets(inputTarget, geohash).map { rt =>
          if (rt.size == 100) {
            topTweetsByGeoTake100Counter.incr(1)
          }
          FutureOps
            .mapCollect((inputTarget.params(FS.EnableVFInTweetypie) match {
              case true => tweetyPieStore
              case false => tweetyPieStoreNoVF
            }).multiGet(rt.map { case (tweetId, _) => tweetId }.toSet))
            .map { tweetyPieResultMap =>
              Some(
                buildTopTweetsByGeoRawCandidates(
                  inputTarget,
                  None,
                  filterOutReplyTweet(
                    tweetyPieResultMap,
                    nonReplyTweetsCounter
                  )
                )
              )
            }
        }.flatten
      }
    }
  }

  private def getGeoHashForUsers(
    inputTarget: Target
  ): Future[Option[String]] = {

    inputTarget.targetUser.flatMap {
      case Some(user) =>
        user.userType match {
          case UserType.Soft =>
            softUserGeoLocationStore
              .get(inputTarget.targetId)
              .map(_.flatMap(_.geohash.flatMap(_.stringGeohash)))

          case _ =>
            geoduckStoreV2.get(inputTarget.targetId).map(_.flatMap(_.geohash))
        }

      case None => Future.None
    }
  }

  private def buildTopTweetsByGeoRawCandidates(
    target: PushTypes.Target,
    locationName: Option[String],
    topTweets: Map[Long, Option[TweetyPieResult]]
  ): Seq[RawCandidate with TweetCandidate] = {
    val candidates = topTweets.map { tweetIdTweetyPieResultMap =>
      PushAdaptorUtil.generateOutOfNetworkTweetCandidates(
        inputTarget = target,
        id = tweetIdTweetyPieResultMap._1,
        mediaCRT = MediaCRT(
          CommonRecommendationType.GeoPopTweet,
          CommonRecommendationType.GeoPopTweet,
          CommonRecommendationType.GeoPopTweet
        ),
        result = tweetIdTweetyPieResultMap._2,
        localizedEntity = None
      )
    }.toSeq
    outputTopTweetsByGeoCounter.add(candidates.length)
    candidates
  }

  private val topTweetsByGeoFrequencyPredicate = {
    TargetPredicates
      .pushRecTypeFatiguePredicate(
        CommonRecommendationType.GeoPopTweet,
        FS.TopTweetsByGeoPushInterval,
        FS.MaxTopTweetsByGeoPushGivenInterval,
        stats
      )
  }

  def getAvailabilityForDormantUser(target: Target): Future[Boolean] = {
    lazy val isDormantUserNotFatigued = topTweetsByGeoFrequencyPredicate(Seq(target)).map(_.head)
    lazy val enableTopTweetsByGeoForDormantUsers =
      target.params(FS.EnableTopTweetsByGeoCandidatesForDormantUsers)

    target.lastHTLVisitTimestamp.flatMap {
      case Some(lastHTLTimestamp) =>
        val minTimeSinceLastLogin =
          target.params(FS.MinimumTimeSinceLastLoginForGeoPopTweetPush).ago
        val timeSinceInactive = target.params(FS.TimeSinceLastLoginForGeoPopTweetPush).ago
        val lastActiveTimestamp = Time.fromMilliseconds(lastHTLTimestamp)
        if (lastActiveTimestamp > minTimeSinceLastLogin) {
          nonDormantUsersSince14DaysCounter.incr()
          Future.False
        } else {
          dormantUsersSince14DaysCounter.incr()
          isDormantUserNotFatigued.map { isUserNotFatigued =>
            lastActiveTimestamp < timeSinceInactive &&
            enableTopTweetsByGeoForDormantUsers &&
            isUserNotFatigued
          }
        }
      case _ =>
        dormantUsersSince30DaysCounter.incr()
        isDormantUserNotFatigued.map { isUserNotFatigued =>
          enableTopTweetsByGeoForDormantUsers && isUserNotFatigued
        }
    }
  }

  def getAvailabilityForPlaybookSetUp(target: Target): Future[Boolean] = {
    lazy val enableTopTweetsByGeoForNewUsers = target.params(FS.EnableTopTweetsByGeoCandidates)
    val isTargetEligibleForMrFatigueCheck = target.isAccountAtleastNDaysOld(
      target.params(FS.MrMinDurationSincePushForTopTweetsByGeoPushes))
    val isMrFatigueCheckEnabled =
      target.params(FS.EnableMrMinDurationSinceMrPushFatigue)
    val applyPredicateForTopTweetsByGeo =
      if (isMrFatigueCheckEnabled) {
        if (isTargetEligibleForMrFatigueCheck) {
          DiscoverTwitterPredicate
            .minDurationElapsedSinceLastMrPushPredicate(
              name,
              FS.MrMinDurationSincePushForTopTweetsByGeoPushes,
              stats
            ).andThen(
              topTweetsByGeoFrequencyPredicate
            )(Seq(target)).map(_.head)
        } else {
          Future.False
        }
      } else {
        topTweetsByGeoFrequencyPredicate(Seq(target)).map(_.head)
      }
    applyPredicateForTopTweetsByGeo.map { predicateResult =>
      predicateResult && enableTopTweetsByGeoForNewUsers
    }
  }

  override def isCandidateSourceAvailable(target: Target): Future[Boolean] = {
    if (target.isLoggedOutUser) {
      Future.True
    } else {
      PushDeviceUtil
        .isRecommendationsEligible(target).map(
          _ && target.params(PushParams.PopGeoCandidatesDecider)).flatMap { isAvailable =>
          if (isAvailable) {
            Future
              .join(getAvailabilityForDormantUser(target), getAvailabilityForPlaybookSetUp(target))
              .map {
                case (isAvailableForDormantUser, isAvailableForPlaybook) =>
                  isAvailableForDormantUser || isAvailableForPlaybook
                case _ => false
              }
          } else Future.False
        }
    }
  }
}