feat: Add sidekiq jobs to monitor applied SLAs (#8828)

Fixes: https://linear.app/chatwoot/issue/CW-2983/sidekiq-jobservice-to-monitor-sla-breach

Co-authored-by: Sojan <sojan@pepalo.com>

spec/enterprise/services/sla/evaluate_applied_sla_service_spec.rb

@@ -0,0 +1,141 @@
+require 'rails_helper'
+
+RSpec.describe Sla::EvaluateAppliedSlaService do
+  let!(:conversation) { create(:conversation, created_at: 6.hours.ago) }
+  let!(:sla_policy) do
+    create(:sla_policy, account: conversation.account,
+                        first_response_time_threshold: nil,
+                        next_response_time_threshold: nil,
+                        resolution_time_threshold: nil)
+  end
+  let!(:applied_sla) { create(:applied_sla, conversation: conversation, sla_policy: sla_policy, sla_status: 'active') }
+
+  describe '#perform - SLA misses' do
+    context 'when first response SLA is missed' do
+      before { sla_policy.update(first_response_time_threshold: 1.hour) }
+
+      it 'updates the SLA status to missed and logs a warning' do
+        allow(Rails.logger).to receive(:warn)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:warn).with("SLA missed for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('missed')
+      end
+    end
+
+    context 'when next response SLA is missed' do
+      before do
+        sla_policy.update(next_response_time_threshold: 1.hour)
+        conversation.update(first_reply_created_at: 5.hours.ago, waiting_since: 5.hours.ago)
+      end
+
+      it 'updates the SLA status to missed and logs a warning' do
+        allow(Rails.logger).to receive(:warn)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:warn).with("SLA missed for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('missed')
+      end
+    end
+
+    context 'when resolution time SLA is missed' do
+      before { sla_policy.update(resolution_time_threshold: 1.hour) }
+
+      it 'updates the SLA status to missed and logs a warning' do
+        allow(Rails.logger).to receive(:warn)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:warn).with("SLA missed for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('missed')
+      end
+    end
+
+    # We will mark resolved miss only if while processing the SLA
+    # if the conversation is resolved and the resolution time is missed by small margins then we will not mark it as missed
+    context 'when resolved conversation with resolution time SLA is missed' do
+      before do
+        conversation.resolved!
+        sla_policy.update(resolution_time_threshold: 1.hour)
+      end
+
+      it 'does not update the SLA status to missed' do
+        described_class.new(applied_sla: applied_sla).perform
+        expect(applied_sla.reload.sla_status).to eq('hit')
+      end
+    end
+
+    context 'when multiple SLAs are missed' do
+      before do
+        sla_policy.update(first_response_time_threshold: 1.hour, next_response_time_threshold: 1.hour, resolution_time_threshold: 1.hour)
+        conversation.update(first_reply_created_at: 5.hours.ago, waiting_since: 5.hours.ago)
+      end
+
+      it 'updates the SLA status to missed and logs a warning' do
+        allow(Rails.logger).to receive(:warn)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:warn).with("SLA missed for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}").exactly(1).time
+        expect(applied_sla.reload.sla_status).to eq('missed')
+      end
+    end
+  end
+
+  describe '#perform - SLA hits' do
+    context 'when first response SLA is hit' do
+      before do
+        sla_policy.update(first_response_time_threshold: 6.hours)
+        conversation.update(first_reply_created_at: 30.minutes.ago)
+      end
+
+      it 'sla remains active until conversation is resolved' do
+        described_class.new(applied_sla: applied_sla).perform
+        expect(applied_sla.reload.sla_status).to eq('active')
+      end
+
+      it 'updates the SLA status to hit and logs an info when conversations is resolved' do
+        conversation.resolved!
+        allow(Rails.logger).to receive(:info)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:info).with("SLA hit for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('hit')
+      end
+    end
+
+    context 'when next response SLA is hit' do
+      before do
+        sla_policy.update(next_response_time_threshold: 6.hours)
+        conversation.update(first_reply_created_at: 30.minutes.ago, waiting_since: nil)
+      end
+
+      it 'sla remains active until conversation is resolved' do
+        described_class.new(applied_sla: applied_sla).perform
+        expect(applied_sla.reload.sla_status).to eq('active')
+      end
+
+      it 'updates the SLA status to hit and logs an info when conversations is resolved' do
+        conversation.resolved!
+        allow(Rails.logger).to receive(:info)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:info).with("SLA hit for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('hit')
+      end
+    end
+
+    context 'when resolution time SLA is hit' do
+      before do
+        sla_policy.update(resolution_time_threshold: 8.hours)
+        conversation.resolved!
+      end
+
+      it 'updates the SLA status to hit and logs an info' do
+        allow(Rails.logger).to receive(:info)
+        described_class.new(applied_sla: applied_sla).perform
+        expect(Rails.logger).to have_received(:info).with("SLA hit for conversation #{conversation.id} in account " \
+                                                          "#{applied_sla.account_id} for sla_policy #{sla_policy.id}")
+        expect(applied_sla.reload.sla_status).to eq('hit')
+      end
+    end
+  end
+end