class ScoreCalculator def self.default_score_weights { reply_count: 5, like_score: 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 percent rankings of the posts exec_sql("UPDATE posts SET percent_rank = x.percent_rank FROM (SELECT id, percent_rank() OVER (PARTITION BY topic_id ORDER BY SCORE DESC) as percent_rank FROM posts) AS x WHERE x.id = posts.id") # Update the topics exec_sql "UPDATE topics AS t SET has_best_of = (t.like_count >= :likes_required AND t.posts_count >= :posts_required AND x.max_score >= :score_required), score = x.avg_score FROM (SELECT p.topic_id, MAX(p.score) AS max_score, AVG(p.score) AS avg_score FROM posts AS p GROUP BY p.topic_id) AS x WHERE x.topic_id = t.id", likes_required: SiteSetting.best_of_likes_required, posts_required: SiteSetting.best_of_posts_required, score_required: SiteSetting.best_of_score_threshold # Update percentage rank of topics exec_sql("UPDATE topics SET percent_rank = x.percent_rank FROM (SELECT id, percent_rank() OVER (ORDER BY SCORE DESC) as percent_rank FROM topics) AS x WHERE x.id = topics.id") end private def exec_sql(sql, params=nil) 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