Increment user's concept stats on level completion

app/schemas/models/user.coffee

@@ -280,6 +280,7 @@ _.extend UserSchema.properties,
     pollMiscPatches: c.int()
     campaignTranslationPatches: c.int()
     campaignMiscPatches: c.int()
+    concepts: {type: 'object', additionalProperties: c.int(), description: 'Number of levels completed using each programming concept.'}
 
   earned: c.RewardSchema 'earned by achievements'
   purchased: c.RewardSchema 'purchased with gems or money'

app/views/play/level/tome/SpellView.coffee

@@ -106,6 +106,7 @@ module.exports = class SpellView extends CocoView
     @ace.setAnimatedScroll true
     @ace.setShowFoldWidgets false
     @ace.setKeyboardHandler @keyBindings[aceConfig.keyBindings ? 'default']
+    @ace.$blockScrolling = Infinity
     @toggleControls null, @writable
     @aceSession.selection.on 'changeCursor', @onCursorActivity
     $(@ace.container).find('.ace_gutter').on 'click mouseenter', '.ace_error, .ace_warning, .ace_info', @onAnnotationClick
@@ -459,7 +460,7 @@ module.exports = class SpellView extends CocoView
             entry.captureReturn = switch e.language
               when 'io' then varName + ' := '
               when 'javascript' then 'var ' + varName + ' = '
-              when 'clojure' then '(let [' + varName + ' ' 
+              when 'clojure' then '(let [' + varName + ' '
               else varName + ' = '
 
     # TODO: Generalize this snippet replacement

server/levels/sessions/LevelSession.coffee

@@ -44,6 +44,7 @@ LevelSessionSchema.post 'init', (doc) ->
 
 LevelSessionSchema.pre 'save', (next) ->
   User = require '../../users/User'  # Avoid mutual inclusion cycles
+  Level = require '../Level'
   @set('changed', new Date())
 
   id = @get('id')
@@ -54,12 +55,20 @@ LevelSessionSchema.pre 'save', (next) ->
 
   # Newly completed level
   if not (initd and @previousStateInfo['state.complete']) and @get('state.complete')
-    User.findByIdAndUpdate userID, {$inc: 'stats.gamesCompleted': 1}, {}, (err, doc) ->
+    Level.findOne({slug: levelID}).select('concepts -_id').lean().exec (err, level) ->
       log.error err if err?
-      oldCopy = doc.toObject()
-      oldCopy.stats = _.clone oldCopy.stats
-      oldCopy.stats.gamesCompleted = oldCopy.stats.gamesCompleted - 1
-      User.schema.statics.createNewEarnedAchievements doc, oldCopy
+      update = $inc: {'stats.gamesCompleted': 1}
+      for concept in level?.concepts ? []
+        update.$inc["stats.concepts.#{concept}"] = 1
+      User.findByIdAndUpdate userID, update, {}, (err, user) ->
+        log.error err if err?
+        oldCopy = user.toObject()
+        oldCopy.stats = _.clone oldCopy.stats
+        --oldCopy.stats.gamesCompleted
+        oldCopy.stats.concepts ?= {}
+        for concept in level?.concepts ? []
+          --oldCopy.stats.concepts[concept]
+        User.schema.statics.createNewEarnedAchievements user, oldCopy
     activeUserEvent = "level-completed/#{levelID}"
 
   # Spent at least 30s playing this level

server/users/User.coffee

@@ -192,7 +192,14 @@ UserSchema.statics.incrementStat = (id, statName, done, inc=1) ->
     user.incrementStat statName, done, inc
 
 UserSchema.methods.incrementStat = (statName, done, inc=1) ->
-  @set statName, (@get(statName) or 0) + inc
+  if /^concepts\./.test statName
+    # Concept stats are nested a level deeper.
+    concepts = @get('concepts') or {}
+    concept = statName.split('.')[1]
+    concepts[concept] = (concepts[concept] or 0) + inc
+    @set 'concepts', concepts
+  else
+    @set statName, (@get(statName) or 0) + inc
   @save (err) -> done?(err)
 
 UserSchema.statics.unconflictName = unconflictName = (name, done) ->