Block tipline users when they send more than X messages in 24 hours

"X" is defined by a configuration key but has a default value.

Reference: CV2-3860.

app/models/tipline_message.rb

@@ -6,6 +6,8 @@ class TiplineMessage < ApplicationRecord
   validates_presence_of :team, :uid, :platform, :language, :direction, :sent_at, :payload, :state
   validates_inclusion_of :state, in: ['sent', 'received', 'delivered']
 
+  after_commit :verify_user_rate_limit, on: :create
+
   def save_ignoring_duplicate!
     begin
       self.save!
@@ -14,6 +16,16 @@ def save_ignoring_duplicate!
     end
   end
 
+  private
+
+  def verify_user_rate_limit
+    rate_limit = CheckConfig.get('tipline_user_max_messages_per_day', 1500, :integer)
+    # Block tipline user when they have sent more than X messages in 24 hours
+    if self.state == 'received' && TiplineMessage.where(uid: self.uid, created_at: Time.now.ago(1.day)..Time.now, state: 'received').count > rate_limit
+      Bot::Smooch.block_user(self.uid)
+    end
+  end
+
   class << self
     def from_smooch_payload(msg, payload, event = nil, language = nil)
       msg = msg.with_indifferent_access

config/config.yml.example

@@ -258,6 +258,13 @@ development: &default
   otel_traces_sampler:
   otel_custom_sampling_rate:
 
+  # Rate limit for tipline submissions, tipline users are blocked after reaching this limit
+  #
+  # OPTIONAL
+  # When not set, a default number will be used.
+  #
+  tipline_user_max_messages_per_day: 1500
+
 test:
   <<: *default
   checkdesk_base_url_private: http://api:3000

test/models/tipline_message_test.rb

@@ -198,4 +198,26 @@ def setup
       end
     end
   end
+
+  test "should block user when rate limit is reached" do
+    uid = random_string
+    assert !Bot::Smooch.user_blocked?(uid)
+    stub_configs({ 'tipline_user_max_messages_per_day' => 2 }) do
+      # User sent a message
+      create_tipline_message uid: uid, state: 'received'
+      assert !Bot::Smooch.user_blocked?(uid)
+      # User sent a message
+      create_tipline_message uid: uid, state: 'received'
+      assert !Bot::Smooch.user_blocked?(uid)
+      # Another user sent a message
+      create_tipline_message state: 'received'
+      assert !Bot::Smooch.user_blocked?(uid)
+      # User received a message
+      create_tipline_message uid: uid, state: 'delivered'
+      assert !Bot::Smooch.user_blocked?(uid)
+      # User sent a message and is now over rate limit, so should be blocked
+      create_tipline_message uid: uid, state: 'received'
+      assert Bot::Smooch.user_blocked?(uid)
+    end
+  end
 end