log = require 'winston'
mongoose = require 'mongoose'
async = require 'async'
Achievement = require './Achievement'
EarnedAchievement = require './EarnedAchievement'
User = require '../users/User'
Handler = require '../commons/Handler'
LocalMongo = require '../../app/lib/LocalMongo'

class EarnedAchievementHandler extends Handler
  modelClass: EarnedAchievement

  # Don't allow POSTs or anything yet
  hasAccess: (req) ->
    req.method is 'GET' # or req.user.isAdmin()

  get: (req, res) ->
    return @getByAchievementIDs(req, res) if req.query.view is 'get-by-achievement-ids'
    super(arguments...)

  getByAchievementIDs: (req, res) ->
    query = { user: req.user._id+''}
    ids = req.query.achievementIDs
    if (not ids) or (ids.length is 0)
      return @sendBadInputError(res, 'For a get-by-achievement-ids request, need to provide ids.')

    ids = ids.split(',')
    for id in ids
      if not Handler.isID(id)
        return @sendBadInputError(res, "Not a MongoDB ObjectId: #{id}")

    query.achievement = {$in: ids}
    EarnedAchievement.find query, (err, earnedAchievements) ->
      return @sendDatabaseError(res, err) if err
      res.send(earnedAchievements)

  recalculate: (req, res) ->
    onSuccess = (data) => log.debug 'Finished recalculating achievements'
    if 'achievements' of req.body # Support both slugs and IDs separated by commas
      achievementSlugsOrIDs = req.body.achievements
      EarnedAchievementHandler.recalculate achievementSlugsOrIDs, onSuccess
    else
      EarnedAchievementHandler.recalculate onSuccess
    @sendAccepted res, {}

  @recalculate: (callbackOrSlugsOrIDs, callback) ->
    if _.isArray callbackOrSlugsOrIDs # slugs or ids
      achievementSlugs = (thing for thing in callbackOrSlugsOrIDs when not Handler.isID(thing))
      achievementIDs = (thing for thing in callbackOrSlugsOrIDs when Handler.isID(thing))
      recalculatingAll = false
    else # just a callback
      callback = callbackOrSlugsOrIDs
      recalculatingAll = true
    t0 = new Date().getTime()
    total = 100000
    User.count {anonymous:false}, (err, count) -> total = count

    onFinished = ->
      t1 = new Date().getTime()
      runningTime = ((t1-t0)/1000/60/60).toFixed(2)
      console.log "we finished in #{runningTime} hours"
      callback arguments...

    filter = {}
    filter.$or = [
      {_id: $in: achievementIDs},
      {slug: $in: achievementSlugs}
    ] if achievementSlugs? or achievementIDs?

    # Fetch all relevant achievements
    Achievement.find filter, (err, achievements) ->
      callback?(err) if err?
      callback?(new Error 'No achievements to recalculate') unless achievements.length
      log.info "Recalculating a total of #{achievements.length} achievements..."

      # Fetch every single user. This tends to get big so do it in a streaming fashion.
      userStream = User.find().sort('_id').stream()
      streamFinished = false
      usersTotal = 0
      usersFinished = 0
      numberRunning = 0
      doneWithUser = ->
        ++usersFinished
        numberRunning -= 1
        userStream.resume()

        onFinished?() if streamFinished and usersFinished is usersTotal
      userStream.on 'error', (err) -> log.error err
      userStream.on 'close', -> streamFinished = true
      userStream.on 'data',  (user) ->
        ++usersTotal
        numberRunning += 1
        userStream.pause() if numberRunning > 20

        # Keep track of a user's already achieved in order to set the notified values correctly
        userID = user.get('_id').toHexString()

        # Fetch all of a user's earned achievements
        EarnedAchievement.find {user: userID}, (err, alreadyEarned) ->
          alreadyEarnedIDs = []
          previousPoints = 0
          previousRewards = heroes: [], items: [], levels: [], gems: 0
          async.each alreadyEarned, ((earned, doneWithEarned) ->
            if (_.find achievements, (single) -> earned.get('achievement') is single.get('_id').toHexString()) # if already earned
              alreadyEarnedIDs.push earned.get('achievement')
              previousPoints += earned.get 'earnedPoints'
              for rewardType in ['heroes', 'items', 'levels']
                previousRewards[rewardType] = previousRewards[rewardType].concat(earned.get('earnedRewards')?[rewardType] ? [])
              previousRewards.gems += earned.get('earnedRewards')?.gems ? 0
            doneWithEarned()
          ), (err) -> # After checking already achieved
            log.error err if err
            # TODO maybe also delete earned? Make sure you don't delete too many

            newTotalPoints = 0
            newTotalRewards = heroes: [], items: [], levels: [], gems: 0

            async.each achievements, ((achievement, doneWithAchievement) ->
              isRepeatable = achievement.get('proportionalTo')?
              model = mongoose.modelNameByCollection(achievement.get('collection'))
              return doneWithAchievement new Error "Model with collection '#{achievement.get 'collection'}' doesn't exist." unless model?

              finalQuery = _.clone achievement.get 'query'
              return doneWithAchievement() if _.isEmpty finalQuery
              finalQuery.$or = [{}, {}] # Allow both ObjectIDs or hex string IDs
              finalQuery.$or[0][achievement.userField] = userID
              finalQuery.$or[1][achievement.userField] = mongoose.Types.ObjectId userID

              model.findOne finalQuery, (err, something) ->
                return doneWithAchievement() if _.isEmpty something

                #log.debug "Matched an achievement: #{achievement.get 'name'} for #{user.get 'name'}"

                earned =
                  user: userID
                  achievement: achievement._id.toHexString()
                  achievementName: achievement.get 'name'
                  notified: achievement._id in alreadyEarnedIDs

                if isRepeatable
                  earned.achievedAmount = something.get(achievement.get 'proportionalTo')
                  earned.previouslyAchievedAmount = 0

                  expFunction = achievement.getExpFunction()
                  newPoints = expFunction(earned.achievedAmount) * achievement.get('worth') ? 10
                else
                  newPoints = achievement.get('worth') ? 10

                earned.earnedPoints = newPoints
                newTotalPoints += newPoints

                earned.earnedRewards = achievement.get('rewards')
                for rewardType in ['heroes', 'items', 'levels']
                  newTotalRewards[rewardType] = newTotalRewards[rewardType].concat(achievement.get('rewards')?[rewardType] ? [])
                newTotalRewards.gems += achievement.get('rewards')?.gems ? 0

                EarnedAchievement.update {achievement:earned.achievement, user:earned.user}, earned, {upsert: true}, (err) ->
                  doneWithAchievement err
            ), (err) -> # Wrap up a user, save points
              log.error err if err
              #console.log 'User', user.get('name'), 'had newTotalPoints', newTotalPoints, 'and newTotalRewards', newTotalRewards, 'previousRewards', previousRewards
              return doneWithUser(user) unless newTotalPoints or newTotalRewards.gems or _.some(newTotalRewards, (r) -> r.length)
#              log.debug "Matched a total of #{newTotalPoints} new points"
#              log.debug "Incrementing score for these achievements with #{newTotalPoints - previousPoints}"
              pointDelta = newTotalPoints - previousPoints
              pctDone = (100 * usersFinished / total).toFixed(2)
              console.log "Updated points to #{newTotalPoints} (#{if pointDelta < 0 then '' else '+'}#{pointDelta}) for #{user.get('name') or '???'} (#{user.get('_id')}) (#{pctDone}%)"
              if recalculatingAll
                update = {$set: {points: newTotalPoints, 'earned.gems': 0, 'earned.heroes': [], 'earned.items': [], 'earned.levels': []}}
              else
                update = {$inc: {points: pointDelta}}
                secondUpdate = {}  # In case we need to pull, then push.
              for rewardType, rewards of newTotalRewards
                updateKey = "earned.#{rewardType}"
                if rewardType is 'gems'
                  if recalculatingAll
                    update.$set[updateKey] = rewards
                  else
                    update.$inc[updateKey] = rewards - previousRewards.gems
                else
                  if recalculatingAll
                    update.$set[updateKey] = _.uniq rewards
                  else
                    previousCounts = _.countBy previousRewards[rewardType]
                    newCounts = _.countBy rewards
                    relevantRewards = _.union _.keys(previousCounts), _.keys(newCounts)
                    for reward in relevantRewards
                      [previousCount, newCount] = [previousCounts[reward], newCounts[reward]]
                      if newCount and not previousCount
                        update.$addToSet ?= {}
                        update.$addToSet[updateKey] ?= {$each: []}
                        update.$addToSet[updateKey].$each.push reward
                      else if previousCount and not newCount
                        # Might $pull $each also work here?
                        update.$pullAll ?= {}
                        update.$pullAll[updateKey] ?= []
                        update.$pullAll[updateKey].push reward
                    if update.$addToSet?[updateKey] and update.$pullAll?[updateKey]
                      # Perform the update in two calls to avoid "MongoError: Cannot update 'earned.levels' and 'earned.levels' at the same time"
                      secondUpdate.$addToSet ?= {}
                      secondUpdate.$addToSet[updateKey] = update.$addToSet[updateKey]
                      delete update.$addToSet[updateKey]
                      delete update.$addToSet unless _.size update.$addToSet
              #console.log 'recalculatingAll?', recalculatingAll, 'so update is', update, 'secondUpdate', secondUpdate
              User.update {_id: userID}, update, {}, (err) ->
                log.error err if err?
                if _.size secondUpdate
                  User.update {_id: userID}, secondUpdate, {}, (err) ->
                    log.error err if err?
                    doneWithUser user
                else
                  doneWithUser user


module.exports = new EarnedAchievementHandler()