3 files changed, 33 insertions, 30 deletions
diff --git a/app/models/trends/base.rb b/app/models/trends/base.rb
index 788f128a0..b767dcb1a 100644
--- a/app/models/trends/base.rb
+++ b/app/models/trends/base.rb
@@ -3,6 +3,19 @@
 class Trends::Base
   include Redisable
 
+  class_attribute :default_options
+
+  attr_reader :options
+
+  # @param [Hash] options
+  # @option options [Integer] :threshold Minimum amount of uses by unique accounts to begin calculating the score
+  # @option options [Integer] :review_threshold Minimum rank (lower = better) before requesting a review
+  # @option options [ActiveSupport::Duration] :max_score_cooldown For this amount of time, the peak score (if bigger than current score) is decayed-from
+  # @option options [ActiveSupport::Duration] :max_score_halflife How quickly a peak score decays
+  def initialize(options = {})
+    @options = self.class.default_options.merge(options)
+  end
+
   def register(_status)
     raise NotImplementedError
   end
diff --git a/app/models/trends/links.rb b/app/models/trends/links.rb
index a7cd9e29d..a0d65138b 100644
--- a/app/models/trends/links.rb
+++ b/app/models/trends/links.rb
@@ -3,17 +3,12 @@
 class Trends::Links < Trends::Base
   PREFIX = 'trending_links'
 
-  # Minimum amount of uses by unique accounts to begin calculating the score
-  THRESHOLD = 15
-
-  # Minimum rank (lower = better) before requesting a review
-  REVIEW_THRESHOLD = 10
-
-  # For this amount of time, the peak score (if bigger than current score) is decayed-from
-  MAX_SCORE_COOLDOWN = 2.days.freeze
-
-  # How quickly a peak score decays
-  MAX_SCORE_HALFLIFE = 8.hours.freeze
+  self.default_options = {
+    threshold: 15,
+    review_threshold: 10,
+    max_score_cooldown: 2.days.freeze,
+    max_score_halflife: 8.hours.freeze,
+  }
 
   def register(status, at_time = Time.now.utc)
     original_status = status.reblog? ? status.reblog : status
@@ -81,10 +76,10 @@ class Trends::Links < Trends::Base
       observed  = preview_card.history.get(at_time).accounts.to_f
       max_time  = preview_card.max_score_at
       max_score = preview_card.max_score
-      max_score = 0 if max_time.nil? || max_time < (at_time - MAX_SCORE_COOLDOWN)
+      max_score = 0 if max_time.nil? || max_time < (at_time - options[:max_score_cooldown])
 
       score = begin
-        if expected > observed || observed < THRESHOLD
+        if expected > observed || observed < options[:threshold]
           0
         else
           ((observed - expected)**2) / expected
@@ -99,7 +94,7 @@ class Trends::Links < Trends::Base
         preview_card.update_columns(max_score: max_score, max_score_at: max_time)
       end
 
-      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / MAX_SCORE_HALFLIFE.to_f))
+      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / options[:max_score_halflife].to_f))
 
       if decaying_score.zero?
         redis.zrem("#{PREFIX}:all", preview_card.id)
@@ -117,6 +112,6 @@ class Trends::Links < Trends::Base
   end
 
   def would_be_trending?(id)
-    score(id) > score_at_rank(REVIEW_THRESHOLD - 1)
+    score(id) > score_at_rank(options[:review_threshold] - 1)
   end
 end
diff --git a/app/models/trends/tags.rb b/app/models/trends/tags.rb
index 027e3dbac..13e0ab56b 100644
--- a/app/models/trends/tags.rb
+++ b/app/models/trends/tags.rb
@@ -3,17 +3,12 @@
 class Trends::Tags < Trends::Base
   PREFIX = 'trending_tags'
 
-  # Minimum amount of uses by unique accounts to begin calculating the score
-  THRESHOLD = 15
-
-  # Minimum rank (lower = better) before requesting a review
-  REVIEW_THRESHOLD = 10
-
-  # For this amount of time, the peak score (if bigger than current score) is decayed-from
-  MAX_SCORE_COOLDOWN = 2.days.freeze
-
-  # How quickly a peak score decays
-  MAX_SCORE_HALFLIFE = 4.hours.freeze
+  self.default_options = {
+    threshold: 15,
+    review_threshold: 10,
+    max_score_cooldown: 2.days.freeze,
+    max_score_halflife: 4.hours.freeze,
+  }
 
   def register(status, at_time = Time.now.utc)
     original_status = status.reblog? ? status.reblog : status
@@ -75,10 +70,10 @@ class Trends::Tags < Trends::Base
       observed  = tag.history.get(at_time).accounts.to_f
       max_time  = tag.max_score_at
       max_score = tag.max_score
-      max_score = 0 if max_time.nil? || max_time < (at_time - MAX_SCORE_COOLDOWN)
+      max_score = 0 if max_time.nil? || max_time < (at_time - options[:max_score_cooldown])
 
       score = begin
-        if expected > observed || observed < THRESHOLD
+        if expected > observed || observed < options[:threshold]
           0
         else
           ((observed - expected)**2) / expected
@@ -93,7 +88,7 @@ class Trends::Tags < Trends::Base
         tag.update_columns(max_score: max_score, max_score_at: max_time)
       end
 
-      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / MAX_SCORE_HALFLIFE.to_f))
+      decaying_score = max_score * (0.5**((at_time.to_f - max_time.to_f) / options[:max_score_halflife].to_f))
 
       if decaying_score.zero?
         redis.zrem("#{PREFIX}:all", tag.id)
@@ -111,6 +106,6 @@ class Trends::Tags < Trends::Base
   end
 
   def would_be_trending?(id)
-    score(id) > score_at_rank(REVIEW_THRESHOLD - 1)
+    score(id) > score_at_rank(options[:review_threshold] - 1)
   end
 end