1 files changed, 39 insertions, 0 deletions
diff --git a/app/lib/potential_friendship_tracker.rb b/app/lib/potential_friendship_tracker.rb
new file mode 100644
index 000000000..362482669
--- /dev/null
+++ b/app/lib/potential_friendship_tracker.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class PotentialFriendshipTracker
+  EXPIRE_AFTER = 90.days.seconds
+  MAX_ITEMS    = 80
+
+  WEIGHTS = {
+    reply: 1,
+    favourite: 10,
+    reblog: 20,
+  }.freeze
+
+  class << self
+    def record(account_id, target_account_id, action)
+      key    = "interactions:#{account_id}"
+      weight = WEIGHTS[action]
+
+      redis.zincrby(key, weight, target_account_id)
+      redis.zremrangebyrank(key, 0, -MAX_ITEMS)
+      redis.expire(key, EXPIRE_AFTER)
+    end
+
+    def remove(account_id, target_account_id)
+      redis.zrem("interactions:#{account_id}", target_account_id)
+    end
+
+    def get(account_id, limit: 20, offset: 0)
+      account_ids = redis.zrevrange("interactions:#{account_id}", offset, limit)
+      return [] if account_ids.empty?
+      Account.searchable.where(id: account_ids)
+    end
+
+    private
+
+    def redis
+      Redis.current
+    end
+  end
+end