experiment.rb in metry-2.1.0

- old
+ new
@@ -1,23 +1,46 @@
 module Metry
   class Experiment
+    include MongoMapper::Document
     METHODS = {
-      "rand" => proc{|list, visitor| list.sort_by{rand}.first},
-      "mod_visitor" => proc{|list, visitor| list[(visitor['_id'].to_i-1)%list.size]}, # mod_visitor will only work with predictable_keys = true
+      "rand" => proc{|list, experiment| list.sort_by{rand}.first},
+      "sequential" => proc do |list, experiment|
+        r = list[experiment.counter%list.size]
+        experiment.counter += 1
+        experiment.save
+        r
+      end
     }
-
-    def initialize(name, event, visitor)
-      @key = "experiment:#{name}"
-      @event = event
-      @visitor = visitor
+    
+    key :name, String
+    key :counter, Integer, :default => 0
+    
+    many :cohorts, :class_name => 'Metry::Cohort', :foreign_key => 'experiment_id'
+    many :goals, :class_name => "Metry::Goal", :foreign_key => "experiment_id"
+    
+    def self.find_or_create_by_name(name)
+      find(:first, :conditions => {:name => name}) || create(:name => name)
     end
+        
+    def lookup_cohort(name)
+      cohort = cohorts.find(:first, :conditions => {:name => name})
+      unless cohort
+        cohort = Cohort.create(:name => name)
+        cohorts << cohort
+      end
+      cohort
+    end
     
-    def choose(options, method=nil)
-      unless choice = @visitor[@key]
-        choice = METHODS[method || "rand"][options.keys, @visitor]
-        @visitor[@key] = choice
+    def cohort_for(visitor)
+      cohorts.detect{|e| e.visitor_ids.include?(visitor.id)}
+    end
+    
+    def choose(options, method, event, visitor)
+      cohort = cohort_for(visitor)
+      unless cohort
+        cohort = lookup_cohort(METHODS[method||'rand'][options, self])
+        visitor.in_cohort(cohort)
       end
-      @event[@key] = choice
-      options[choice]
+      cohort.name
     end
   end
 end
\ No newline at end of file