chore: Limit conversation resolution Job (#6433)

We will be adding a limit to the resolution job so that it is performed at a spaced interval. This will ensure there won't be a sudden spike in resource usage

fixes: chatwoot/product#707

app/jobs/conversations/resolution_job.rb

@@ -1,8 +1,9 @@
 class Conversations::ResolutionJob < ApplicationJob
-  queue_as :medium
+  queue_as :low
 
   def perform(account:)
-    resolvable_conversations = account.conversations.resolvable(account.auto_resolve_duration)
+    # limiting the number of conversations to be resolved to avoid any performance issues
+    resolvable_conversations = account.conversations.resolvable(account.auto_resolve_duration).limit(Limits::BULK_ACTIONS_LIMIT)
     resolvable_conversations.each(&:toggle_status)
   end
 end

app/models/conversation.rb

@@ -63,7 +63,7 @@ class Conversation < ApplicationRecord
   scope :assigned, -> { where.not(assignee_id: nil) }
   scope :assigned_to, ->(agent) { where(assignee_id: agent.id) }
   scope :resolvable, lambda { |auto_resolve_duration|
-    return [] if auto_resolve_duration.to_i.zero?
+    return none if auto_resolve_duration.to_i.zero?
 
     open.where('last_activity_at < ? ', Time.now.utc - auto_resolve_duration.days)
   }

lib/limits.rb

@@ -0,0 +1,3 @@
+module Limits
+  BULK_ACTIONS_LIMIT = 100
+end

spec/jobs/conversations/resolution_job_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe Conversations::ResolutionJob, type: :job do
   it 'enqueues the job' do
     expect { job }.to have_enqueued_job(described_class)
       .with(account)
-      .on_queue('medium')
+      .on_queue('low')
   end
 
   it 'does nothing when there is no auto resolve duration' do
@@ -23,4 +23,12 @@ RSpec.describe Conversations::ResolutionJob, type: :job do
     described_class.perform_now(account: account)
     expect(conversation.reload.status).to eq('resolved')
   end
+
+  it 'resolved only a limited number of conversations in a single execution' do
+    stub_const('Limits::BULK_ACTIONS_LIMIT', 2)
+    account.update(auto_resolve_duration: 10)
+    create_list(:conversation, 3, account: account, last_activity_at: 13.days.ago)
+    described_class.perform_now(account: account)
+    expect(account.conversations.resolved.count).to eq(Limits::BULK_ACTIONS_LIMIT)
+  end
 end