Initial release of Discourse

lib/score_calculator.rb

@@ -0,0 +1,58 @@
+class ScoreCalculator
+
+  def self.default_score_weights  
+    {
+      reply_count: 5,
+      like_count: 15,
+      incoming_link_count: 5,
+      bookmark_count: 2,
+      avg_time: 0.05,
+      reads: 0.2
+    }
+  end
+
+  def initialize(weightings=nil)
+    @weightings = weightings || ScoreCalculator.default_score_weights
+  end
+
+  # Calculate the score for all posts based on the weightings
+  def calculate    
+
+    # First update the scores of the posts
+    exec_sql(post_score_sql, @weightings)
+
+    # Update the best of flag
+    exec_sql "
+      UPDATE topics SET has_best_of = 
+        CASE
+          WHEN like_count >= :likes_required AND
+          posts_count >= :posts_required AND
+            EXISTS(SELECT * FROM posts AS p
+                    WHERE p.topic_id = topics.id
+                      AND p.score >= :score_required) THEN true
+        ELSE false
+        END",
+      likes_required: SiteSetting.best_of_likes_required,
+      posts_required: SiteSetting.best_of_posts_required,
+      score_required: SiteSetting.best_of_score_threshold   
+      
+  end
+
+
+  private
+
+    def exec_sql(sql, params)
+      ActiveRecord::Base.exec_sql(sql, params)
+    end
+
+    # Generate a SQL statement to update the scores of all posts
+    def post_score_sql
+      "UPDATE posts SET score = ".tap do |sql|
+        components = []
+        @weightings.keys.each do |k|
+          components << "COALESCE(#{k.to_s}, 0) * :#{k.to_s}"
+        end
+        sql << components.join(" + ")
+      end      
+    end
+end