feat: use captain endpoint config in legacy OpenAI base service (#12060)

This PR migrates the legacy OpenAI integration (where users provide
their own API keys) from using hardcoded `https://api.openai.com`
endpoints to use the configurable `CAPTAIN_OPEN_AI_ENDPOINT` from the
captain configuration. This ensures consistency across all OpenAI
integrations in the platform.

## Changes

- Updated `lib/integrations/openai_base_service.rb` to use captain
endpoint config
- Updated `enterprise/app/models/enterprise/concerns/article.rb` to use
captain endpoint config
- Removed unused `enterprise/lib/chat_gpt.rb` class
- Added tests for endpoint configuration behavior

enterprise/app/models/enterprise/concerns/article.rb

@@ -68,8 +68,16 @@ module Enterprise::Concerns::Article
     headers = { 'Content-Type' => 'application/json', 'Authorization' => "Bearer #{ENV.fetch('OPENAI_API_KEY', nil)}" }
     body = { model: 'gpt-4o', messages: messages, response_format: { type: 'json_object' } }.to_json
     Rails.logger.info "Requesting Chat GPT with body: #{body}"
-    response = HTTParty.post('https://api.openai.com/v1/chat/completions', headers: headers, body: body)
+    response = HTTParty.post(openai_api_url, headers: headers, body: body)
     Rails.logger.info "Chat GPT response: #{response.body}"
     JSON.parse(response.parsed_response['choices'][0]['message']['content'])['search_terms']
   end
+
+  private
+
+  def openai_api_url
+    endpoint = InstallationConfig.find_by(name: 'CAPTAIN_OPEN_AI_ENDPOINT')&.value || 'https://api.openai.com/'
+    endpoint = endpoint.chomp('/')
+    "#{endpoint}/v1/chat/completions"
+  end
 end

enterprise/lib/chat_gpt.rb

@@ -1,62 +0,0 @@
-class ChatGpt
-  def self.base_uri
-    'https://api.openai.com'
-  end
-
-  def initialize(context_sections = '')
-    @model = 'gpt-4o'
-    @messages = [system_message(context_sections)]
-  end
-
-  def generate_response(input, previous_messages = [], role = 'user')
-    @messages += previous_messages
-    @messages << { 'role': role, 'content': input } if input.present?
-
-    response = request_gpt
-    JSON.parse(response['choices'][0]['message']['content'].strip)
-  end
-
-  private
-
-  def system_message(context_sections)
-    {
-      'role': 'system',
-      'content': system_content(context_sections)
-    }
-  end
-
-  def system_content(context_sections)
-    <<~SYSTEM_PROMPT_MESSAGE
-      You are a very enthusiastic customer support representative who loves to help people.
-      Your answers will always be formatted in valid JSON hash, as shown below. Never respond in non JSON format.
-
-      ```
-      {
-       response: '' ,
-      context_ids: [ids],
-      }
-      ```
-
-      response: will be the next response to the conversation
-
-      context_ids: will be an array of unique context IDs that were used to generate the answer. choose top 3.
-
-      The answers will be generated using the information provided at the end of the prompt under the context sections. You will not respond outside the context of the information provided in context sections.
-
-      If the answer is not provided in context sections, Respond to the customer and ask whether they want to talk to another support agent . If they ask to Chat with another agent, return `conversation_handoff' as the response in JSON response
-
-      ----------------------------------
-      Context sections:
-      #{context_sections}
-    SYSTEM_PROMPT_MESSAGE
-  end
-
-  def request_gpt
-    headers = { 'Content-Type' => 'application/json', 'Authorization' => "Bearer #{ENV.fetch('OPENAI_API_KEY')}" }
-    body = { model: @model, messages: @messages, response_format: { type: 'json_object' } }.to_json
-    Rails.logger.info "Requesting Chat GPT with body: #{body}"
-    response = HTTParty.post("#{self.class.base_uri}/v1/chat/completions", headers: headers, body: body)
-    Rails.logger.info "Chat GPT response: #{response.body}"
-    JSON.parse(response.body)
-  end
-end

lib/integrations/openai_base_service.rb

@@ -4,7 +4,6 @@ class Integrations::OpenaiBaseService
   # sticking with 120000 to be safe
   # 120000 * 4 = 480,000 characters (rounding off downwards to 400,000 to be safe)
   TOKEN_LIMIT = 400_000
-  API_URL = 'https://api.openai.com/v1/chat/completions'.freeze
   GPT_MODEL = ENV.fetch('OPENAI_GPT_MODEL', 'gpt-4o-mini').freeze
 
   ALLOWED_EVENT_NAMES = %w[rephrase summarize reply_suggestion fix_spelling_grammar shorten expand make_friendly make_formal simplify].freeze
@@ -81,6 +80,12 @@ class Integrations::OpenaiBaseService
     self.class::CACHEABLE_EVENTS.include?(event_name)
   end
 
+  def api_url
+    endpoint = InstallationConfig.find_by(name: 'CAPTAIN_OPEN_AI_ENDPOINT')&.value || 'https://api.openai.com/'
+    endpoint = endpoint.chomp('/')
+    "#{endpoint}/v1/chat/completions"
+  end
+
   def make_api_call(body)
     headers = {
       'Content-Type' => 'application/json',
@@ -88,7 +93,7 @@ class Integrations::OpenaiBaseService
     }
 
     Rails.logger.info("OpenAI API request: #{body}")
-    response = HTTParty.post(API_URL, headers: headers, body: body)
+    response = HTTParty.post(api_url, headers: headers, body: body)
     Rails.logger.info("OpenAI API response: #{response.body}")
 
     return { error: response.parsed_response, error_code: response.code } unless response.success?

spec/lib/integrations/openai/processor_service_spec.rb

@@ -253,5 +253,52 @@ RSpec.describe Integrations::Openai::ProcessorService do
         expect(result).to eq({ :message => 'This is a reply from openai.' })
       end
     end
+
+    context 'when testing endpoint configuration' do
+      let(:event) { { 'name' => 'rephrase', 'data' => { 'content' => 'test message' } } }
+
+      context 'when CAPTAIN_OPEN_AI_ENDPOINT is not configured' do
+        it 'uses default OpenAI endpoint' do
+          InstallationConfig.find_by(name: 'CAPTAIN_OPEN_AI_ENDPOINT')&.destroy
+
+          stub_request(:post, 'https://api.openai.com/v1/chat/completions')
+            .with(body: anything, headers: expected_headers)
+            .to_return(status: 200, body: openai_response, headers: {})
+
+          result = subject.perform
+          expect(result).to eq({ :message => 'This is a reply from openai.' })
+        end
+      end
+
+      context 'when CAPTAIN_OPEN_AI_ENDPOINT is configured' do
+        before do
+          create(:installation_config, name: 'CAPTAIN_OPEN_AI_ENDPOINT', value: 'https://custom.azure.com/')
+        end
+
+        it 'uses custom endpoint' do
+          stub_request(:post, 'https://custom.azure.com/v1/chat/completions')
+            .with(body: anything, headers: expected_headers)
+            .to_return(status: 200, body: openai_response, headers: {})
+
+          result = subject.perform
+          expect(result).to eq({ :message => 'This is a reply from openai.' })
+        end
+      end
+
+      context 'when CAPTAIN_OPEN_AI_ENDPOINT has trailing slash' do
+        before do
+          create(:installation_config, name: 'CAPTAIN_OPEN_AI_ENDPOINT', value: 'https://custom.azure.com/')
+        end
+
+        it 'properly handles trailing slash' do
+          stub_request(:post, 'https://custom.azure.com/v1/chat/completions')
+            .with(body: anything, headers: expected_headers)
+            .to_return(status: 200, body: openai_response, headers: {})
+
+          result = subject.perform
+          expect(result).to eq({ :message => 'This is a reply from openai.' })
+        end
+      end
+    end
   end
 end