Add completion rates to levels in campaign editor

app/templates/editor/campaign/campaign-level-view.jade

@@ -5,7 +5,24 @@
     a(href="/editor/level/#{level.get('slug')}", target="_blank") (edit)
   p= level.get('description')
 
-  h2 TODO: actually put useful stuff in here
+  h4 Completion Rates
+  if levelCompletions
+    table.table-bordered.table-condensed.table-hover(style='font-size:10pt')
+      thead
+        tr
+          td Date
+          td Started
+          td Finished
+          td Completion %
+      tbody
+        - for (var i = 0; i < levelCompletions.length; i++)
+          tr
+            td= levelCompletions[i].created
+            td= levelCompletions[i].started
+            td= levelCompletions[i].finished
+            td= levelCompletions[i].rate
+  else
+    div Loading...
 
 if level.get('tasks')
   .tasks

app/views/editor/campaign/CampaignLevelView.coffee

@@ -14,11 +14,39 @@ module.exports = class CampaignLevelView extends CocoView
     @fullLevel.fetch()
     @listenToOnce @fullLevel, 'sync', => @render?()
 
+    @levelSlug = @level.get('slug')
+    @getLevelCompletions()
+
   getRenderData: ->
     c = super()
     c.level = if @fullLevel.loaded then @fullLevel else @level
+    c.levelCompletions = @levelCompletions
     c
 
   onClickClose: ->
     @$el.addClass('hidden')
     @trigger 'hidden'
+
+  getLevelCompletions: ->
+    # Fetch last 7 days of level completion counts
+    success = (data) =>
+      return if @destroyed
+      data.sort (a, b) -> if a.created < b.created then 1 else -1
+      mapFn = (item) -> 
+        item.rate = (item.finished / item.started * 100).toFixed(2)
+        item
+      @levelCompletions = _.map data, mapFn, @
+      @render()
+
+    startDay = new Date()
+    startDay.setDate(startDay.getUTCDate() - 6)
+    startDay = startDay.getUTCFullYear() + '-' + (startDay.getUTCMonth() + 1) + '-' + startDay.getUTCDate()
+    
+    # TODO: Why do we need this url dash?
+    request = @supermodel.addRequestResource 'level_completions', {
+      url: '/db/analytics_log_event/-/level_completions'
+      data: {startDay: startDay, slugs: [@levelSlug]}
+      method: 'POST'
+      success: success
+    }, 0
+    request.load()

server/analytics/analytics_log_event_handler.coffee

@@ -1,5 +1,6 @@
 AnalyticsLogEvent = require './AnalyticsLogEvent'
 Handler = require '../commons/Handler'
+log = require 'winston'
 
 class AnalyticsLogEventHandler extends Handler
   modelClass: AnalyticsLogEvent
@@ -17,4 +18,76 @@ class AnalyticsLogEventHandler extends Handler
     instance.set('user', req.user._id)
     instance
 
+  getByRelationship: (req, res, args...) ->
+    return @getLevelCompletionsBySlugs(req, res) if args[1] is 'level_completions'
+    super(arguments...)
+
+  getLevelCompletionsBySlugs: (req, res) ->
+    # Returns an array of per-day level starts and finishes
+    # Parameters:
+    # slugs - array of level slugs
+    # startDay - Inclusive, optional, e.g. '2014-12-14'
+    # endDay - Exclusive, optional, e.g. '2014-12-16'
+    
+    # TODO: An uncached call takes about 15s
+
+    levelSlugs = req.query.slugs or req.body.slugs
+    startDay = req.query.startDay or req.body.startDay
+    endDay = req.query.endDay or req.body.endDay
+
+    return @sendSuccess res, [] unless levelSlugs?
+
+    # Cache results for 1 day
+    @levelCompletionsCache ?= {}
+    @levelCompletionsCachedSince ?= new Date()
+    if (new Date()) - @levelCompletionsCachedSince > 86400 * 1000  # Dumb cache expiration
+      @levelCompletionsCache = {}
+      @levelCompletionsCacheSince = new Date()
+    cacheKey = levelSlugs.join(',')
+    cacheKey += 's' + startDay if startDay?
+    cacheKey += 'e' + endDay if endDay?
+    return @sendSuccess res, levelCompletions if levelCompletions = @levelCompletionsCache[cacheKey]
+
+    # Build query
+    match = {$match: {$and: [{$or: [{"event" : 'Started Level'}, {"event" : 'Saw Victory'}]}]}}
+    match["$match"]["$and"].push created: {$gte: new Date(startDay + "T00:00:00.000Z")} if startDay?
+    match["$match"]["$and"].push created: {$lt: new Date(endDay + "T00:00:00.000Z")} if endDay?
+    project = {"$project": {"_id": 0, "event": 1, "level": {$ifNull: ["$properties.level", "$properties.levelID"]}, "created": {"$concat": [{"$substr":  ["$created", 0, 4]}, "-", {"$substr":  ["$created", 5, 2]}, "-", {"$substr" :  ["$created", 8, 2]}]}}}
+    group = {"$group": {"_id": {"event": "$event", "created": "$created", "level": "$level"}, "count": {"$sum": 1}}}
+    query = AnalyticsLogEvent.aggregate match, project, group
+
+    query.exec (err, data) =>
+      if err? then return @sendDatabaseError res, err
+      
+      # Build per-level-day started and finished counts
+      levelDateMap = {}
+      for item in data
+        created = item._id.created
+        event = item._id.event
+        level = item._id.level
+        continue unless level?
+        # 'Started Level' event uses level slug, 'Saw Victory' event uses level name with caps and spaces.
+        level = level.toLowerCase().replace new RegExp(' ', 'g'), '-' if event is 'Saw Victory'
+        continue unless level in levelSlugs
+
+        levelDateMap[level] ?= {}
+        levelDateMap[level][created] ?= {}
+        levelDateMap[level][created] ?= {}
+        if event is 'Saw Victory'
+          levelDateMap[level][created]['finished'] = item.count
+        else
+          levelDateMap[level][created]['started'] = item.count
+          
+      # Build list of level completions
+      completions = []
+      for level of levelDateMap
+        for created, item of levelDateMap[level]
+          completions.push 
+            level: level
+            created: created
+            started: item.started
+            finished: item.finished
+      @levelCompletionsCache[cacheKey] = completions
+      @sendSuccess res, completions
+
 module.exports = new AnalyticsLogEventHandler()