feat: Add support for persistent copilot threads and messages (#11489)

The agents can see the previous conversations with the copilot if needed
with this change. We would have to cleanup the data after a while. For
now, that is not considered.

This PR adds:
- A new model for copilot_threads (intentionally named thread instead of
conversation to avoid confusion), copilot_messages
- Add the controller to fetch previous threads and messages.

spec/enterprise/controllers/api/v1/accounts/captain/copilot_messages_controller_spec.rb

@@ -0,0 +1,33 @@
+require 'rails_helper'
+
+RSpec.describe 'Api::V1::Accounts::Captain::CopilotMessagesController', type: :request do
+  let(:account) { create(:account) }
+  let(:user) { create(:user, account: account, role: :administrator) }
+  let(:copilot_thread) { create(:captain_copilot_thread, account: account, user: user) }
+  let!(:copilot_message) { create(:captain_copilot_message, copilot_thread: copilot_thread, user: user, account: account) }
+
+  describe 'GET /api/v1/accounts/{account.id}/captain/copilot_threads/{thread.uuid}/copilot_messages' do
+    context 'when it is an authenticated user' do
+      it 'returns all messages' do
+        get "/api/v1/accounts/#{account.id}/captain/copilot_threads/#{copilot_thread.uuid}/copilot_messages",
+            headers: user.create_new_auth_token,
+            as: :json
+
+        expect(response).to have_http_status(:success)
+        json_response = response.parsed_body
+        expect(json_response['payload'].length).to eq(1)
+        expect(json_response['payload'][0]['id']).to eq(copilot_message.id)
+      end
+    end
+
+    context 'when thread uuid is invalid' do
+      it 'returns not found error' do
+        get "/api/v1/accounts/#{account.id}/captain/copilot_threads/invalid-uuid/copilot_messages",
+            headers: user.create_new_auth_token,
+            as: :json
+
+        expect(response).to have_http_status(:not_found)
+      end
+    end
+  end
+end

spec/enterprise/controllers/api/v1/accounts/captain/copilot_threads_controller_spec.rb

@@ -0,0 +1,50 @@
+require 'rails_helper'
+
+RSpec.describe 'Api::V1::Accounts::Captain::CopilotThreads', type: :request do
+  let(:account) { create(:account) }
+  let(:admin) { create(:user, account: account, role: :administrator) }
+  let(:agent) { create(:user, account: account, role: :agent) }
+
+  def json_response
+    JSON.parse(response.body, symbolize_names: true)
+  end
+
+  describe 'GET /api/v1/accounts/{account.id}/captain/copilot_threads' do
+    context 'when it is an un-authenticated user' do
+      it 'does not fetch copilot threads' do
+        get "/api/v1/accounts/#{account.id}/captain/copilot_threads",
+            as: :json
+        expect(response).to have_http_status(:unauthorized)
+      end
+    end
+
+    context 'when it is an agent' do
+      it 'fetches copilot threads for the current user' do
+        # Create threads for the current agent
+        create_list(:captain_copilot_thread, 3, account: account, user: agent)
+        # Create threads for another user (should not be included)
+        create_list(:captain_copilot_thread, 2, account: account, user: admin)
+
+        get "/api/v1/accounts/#{account.id}/captain/copilot_threads",
+            headers: agent.create_new_auth_token,
+            as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(json_response[:payload].length).to eq(3)
+
+        expect(json_response[:payload].map { |thread| thread[:user][:id] }.uniq).to eq([agent.id])
+      end
+
+      it 'returns threads in descending order of creation' do
+        threads = create_list(:captain_copilot_thread, 3, account: account, user: agent)
+
+        get "/api/v1/accounts/#{account.id}/captain/copilot_threads",
+            headers: agent.create_new_auth_token,
+            as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(json_response[:payload].pluck(:id)).to eq(threads.reverse.pluck(:id))
+      end
+    end
+  end
+end

spec/factories/captain/copilot_message.rb

@@ -0,0 +1,9 @@
+FactoryBot.define do
+  factory :captain_copilot_message, class: 'CopilotMessage' do
+    account
+    user
+    copilot_thread { association :captain_copilot_thread }
+    message { { content: 'This is a test message' } }
+    message_type { 'user' }
+  end
+end

spec/factories/captain/copilot_thread.rb

@@ -0,0 +1,8 @@
+FactoryBot.define do
+  factory :captain_copilot_thread, class: 'CopilotThread' do
+    account
+    user
+    title { Faker::Lorem.sentence }
+    uuid { SecureRandom.uuid }
+  end
+end