FEATURE: scale up likes per day as users increase trust level

tl2 = 1.5 times the likes
tl3 = 2 times the likes
tl4 = 3 times the likes

configurable via tl[234]_additional_likes_per_day_multiplier site setting

app/models/post_action.rb

@@ -320,7 +320,16 @@ class PostAction < ActiveRecord::Base
 
     %w(like flag bookmark).each do |type|
       if send("is_#{type}?")
-        @rate_limiter = RateLimiter.new(user, "create_#{type}", SiteSetting.send("max_#{type}s_per_day"), 1.day.to_i)
+        limit = SiteSetting.send("max_#{type}s_per_day")
+
+        if is_like? && user && user.trust_level >= 2
+          multiplier = SiteSetting.send("tl#{user.trust_level}_additional_likes_per_day_multiplier").to_f
+          multiplier = 1.0 if multiplier < 1.0
+
+          limit = (limit * multiplier ).to_i
+        end
+
+        @rate_limiter = RateLimiter.new(user, "create_#{type}",limit, 1.day.to_i)
         return @rate_limiter
       end
     end

config/locales/server.en.yml

@@ -808,6 +808,10 @@ en:
     max_topics_in_first_day: "The maximum number of topics a user is allowed to create in their first day on the site"
     max_replies_in_first_day: "The maximum number of replies a user is allowed to create in their first day on the site"
 
+    tl2_additional_likes_per_day_multiplier: "Increase limit of likes per day for tl2 (member) by multiplying with this number"
+    tl3_additional_likes_per_day_multiplier: "Increase limit of likes per day for tl3 (regular) by multiplying with this number"
+    tl4_additional_likes_per_day_multiplier: "Increase limit of likes per day for tl4 (leader) by multiplying with this number"
+
     num_flags_to_block_new_user: "If a new user's posts get this many spam flags from num_users_to_block_new_user different users, hide all their posts and prevent future posting. 0 to disable."
     num_users_to_block_new_user: "If a new user's posts get num_flags_to_block_new_user spam flags from this many different users, hide all their posts and prevent future posting. 0 to disable."
     notify_mods_when_user_blocked: "If a user is automatically blocked, send a message to all moderators."

config/site_settings.yml

@@ -675,6 +675,9 @@ rate_limits:
   max_invites_per_day: 10
   max_topics_in_first_day: 5
   max_replies_in_first_day: 10
+  tl2_additional_likes_per_day_multiplier: 1.5
+  tl3_additional_likes_per_day_multiplier: 2
+  tl4_additional_likes_per_day_multiplier: 3
 
 developer:
   force_hostname:

lib/rate_limiter.rb

@@ -4,6 +4,8 @@ require_dependency 'rate_limiter/on_create_record'
 # A redis backed rate limiter.
 class RateLimiter
 
+  attr_reader :max, :secs, :user, :key
+
   def self.key_prefix
     "l-rate-limit:"
   end

spec/models/post_action_spec.rb

@@ -506,6 +506,33 @@ describe PostAction do
       topic.reload
       expect(topic.posts.count).to eq(1)
     end
+  end
+
+  describe "rate limiting" do
+
+    def limiter(tl)
+      user = Fabricate.build(:user)
+      user.trust_level = tl
+      action = PostAction.new(user: user, post_action_type_id: PostActionType.types[:like])
+      action.post_action_rate_limiter
+    end
+
+    it "should scale up like limits depending on liker" do
+      expect(limiter(0).max).to eq SiteSetting.max_likes_per_day
+      expect(limiter(1).max).to eq SiteSetting.max_likes_per_day
+      expect(limiter(2).max).to eq (SiteSetting.max_likes_per_day * SiteSetting.tl2_additional_likes_per_day_multiplier).to_i
+      expect(limiter(3).max).to eq (SiteSetting.max_likes_per_day * SiteSetting.tl3_additional_likes_per_day_multiplier).to_i
+      expect(limiter(4).max).to eq (SiteSetting.max_likes_per_day * SiteSetting.tl4_additional_likes_per_day_multiplier).to_i
+
+      SiteSetting.tl2_additional_likes_per_day_multiplier = -1
+      expect(limiter(2).max).to eq SiteSetting.max_likes_per_day
+
+      SiteSetting.tl2_additional_likes_per_day_multiplier = 0.8
+      expect(limiter(2).max).to eq SiteSetting.max_likes_per_day
+
+      SiteSetting.tl2_additional_likes_per_day_multiplier = "bob"
+      expect(limiter(2).max).to eq SiteSetting.max_likes_per_day
+    end
 
   end