REFACTOR: Use LLM abstraction in the AI Helper.

app/controllers/discourse_ai/ai_helper/assistant_controller.rb

@@ -11,7 +11,7 @@ class AssistantController < ::ApplicationController
       def prompts
         render json:
                  ActiveModel::ArraySerializer.new(
-                   DiscourseAi::AiHelper::LlmPrompt.new.available_prompts,
+                   DiscourseAi::AiHelper::Assistant.new.available_prompts,
                    root: false,
                  ),
                status: 200
@@ -29,39 +29,34 @@ def suggest
 
         hijack do
           render json:
-                   DiscourseAi::AiHelper::LlmPrompt.new.generate_and_send_prompt(prompt, params),
+                   DiscourseAi::AiHelper::Assistant.new.generate_and_send_prompt(
+                     prompt,
+                     input,
+                     current_user,
+                   ),
                  status: 200
         end
-      rescue ::DiscourseAi::Inference::OpenAiCompletions::CompletionFailed,
-             ::DiscourseAi::Inference::HuggingFaceTextGeneration::CompletionFailed,
-             ::DiscourseAi::Inference::AnthropicCompletions::CompletionFailed => e
+      rescue DiscourseAi::Completions::Endpoints::Base::CompletionFailed => e
         render_json_error I18n.t("discourse_ai.ai_helper.errors.completion_request_failed"),
                           status: 502
       end
 
       def suggest_title
         input = get_text_param!
-        input_hash = { text: input }
 
-        llm_prompt =
-          DiscourseAi::AiHelper::LlmPrompt
-            .new
-            .available_prompts(name_filter: "generate_titles")
-            .first
-        prompt = CompletionPrompt.find_by(id: llm_prompt[:id])
-        raise Discourse::InvalidParameters.new(:mode) if !prompt || !prompt.enabled?
+        prompt = CompletionPrompt.enabled_by_name("generate_titles")
+        raise Discourse::InvalidParameters.new(:mode) if !prompt
 
         hijack do
           render json:
-                   DiscourseAi::AiHelper::LlmPrompt.new.generate_and_send_prompt(
+                   DiscourseAi::AiHelper::Assistant.new.generate_and_send_prompt(
                      prompt,
-                     input_hash,
+                     input,
+                     current_user,
                    ),
                  status: 200
         end
-      rescue ::DiscourseAi::Inference::OpenAiCompletions::CompletionFailed,
-             ::DiscourseAi::Inference::HuggingFaceTextGeneration::CompletionFailed,
-             ::DiscourseAi::Inference::AnthropicCompletions::CompletionFailed => e
+      rescue DiscourseAi::Completions::Endpoints::Base::CompletionFailed => e
         render_json_error I18n.t("discourse_ai.ai_helper.errors.completion_request_failed"),
                           status: 502
       end
@@ -98,21 +93,18 @@ def suggest_thumbnails
 
       def explain
         post_id = get_post_param!
-        text = get_text_param!
-        post = Post.find_by(id: post_id)
+        term_to_explain = get_text_param!
+        post = Post.includes(:topic).find_by(id: post_id)
 
         raise Discourse::InvalidParameters.new(:post_id) unless post
 
         render json:
-                 DiscourseAi::AiHelper::TopicHelper.new(
-                   { text: text },
-                   current_user,
-                   post: post,
-                 ).explain,
+                 DiscourseAi::AiHelper::TopicHelper.new(current_user).explain(
+                   term_to_explain,
+                   post,
+                 ),
                status: 200
-      rescue ::DiscourseAi::Inference::OpenAiCompletions::CompletionFailed,
-             ::DiscourseAi::Inference::HuggingFaceTextGeneration::CompletionFailed,
-             ::DiscourseAi::Inference::AnthropicCompletions::CompletionFailed => e
+      rescue DiscourseAi::Completions::Endpoints::Base::CompletionFailed => e
         render_json_error I18n.t("discourse_ai.ai_helper.errors.completion_request_failed"),
                           status: 502
       end

app/models/completion_prompt.rb

@@ -1,40 +1,37 @@
 # frozen_string_literal: true
 
 class CompletionPrompt < ActiveRecord::Base
-  # TODO(roman): Remove sept 2023.
-  self.ignored_columns = ["value"]
+  # TODO(roman): Remove may 2024.
+  self.ignored_columns = ["provider"]
+
+  TRANSLATE = -301
+  GENERATE_TITLES = -302
+  PROOFREAD = -303
+  MARKDOWN_TABLE = -304
+  CUSTOM_PROMPT = -305
+  EXPLAIN = -306
 
   enum :prompt_type, { text: 0, list: 1, diff: 2 }
 
   validates :messages, length: { maximum: 20 }
   validate :each_message_length
 
-  def messages_with_user_input(user_input)
-    return messages unless user_input.present?
+  def self.enabled_by_name(name)
+    where(enabled: true).find_by(name: name)
+  end
 
-    if user_input[:custom_prompt].present?
-      case ::DiscourseAi::AiHelper::LlmPrompt.new.enabled_provider
-      when "huggingface"
-        self.messages.each { |msg| msg.sub!("{{custom_prompt}}", user_input[:custom_prompt]) }
-      else
-        self.messages.each do |msg|
-          msg["content"].sub!("{{custom_prompt}}", user_input[:custom_prompt])
-        end
-      end
-    end
+  def messages_with_input(input)
+    return unless input
 
-    case ::DiscourseAi::AiHelper::LlmPrompt.new.enabled_provider
-    when "openai"
-      self.messages << { role: "user", content: user_input[:text] }
-    when "anthropic"
-      self.messages << { "role" => "Input", "content" => "<input>#{user_input[:text]}</input>" }
-    when "huggingface"
-      self.messages.first.sub("{{user_input}}", user_input[:text])
-    end
+    messages_hash.merge(input: "<input>#{input}</input")
   end
 
   private
 
+  def messages_hash
+    @messages_hash ||= messages.symbolize_keys!
+  end
+
   def each_message_length
     messages.each_with_index do |msg, idx|
       next if msg["content"].length <= 1000
@@ -56,7 +53,6 @@ def each_message_length
 #  created_at      :datetime         not null
 #  updated_at      :datetime         not null
 #  messages        :jsonb
-#  provider        :text
 #
 # Indexes
 #