Proof of concept of Discord Bot integration

Author: xfalcox

.gitignore

@@ -1,3 +1,4 @@
 node_modules
 /gems
 /auto_generated
+.env

app/controllers/discourse_ai/discord/bot_controller.rb

@@ -0,0 +1,77 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  module Discord
+    class BotController < ::ApplicationController
+      requires_plugin ::DiscourseAi::PLUGIN_NAME
+
+      skip_before_action :verify_authenticity_token
+
+      def interactions
+        # Request signature verification
+        begin
+          verify_request!
+        rescue Ed25519::VerifyError
+          return head :unauthorized
+        end
+
+        body = JSON.parse(request.body.read)
+
+        if body["type"] == 1
+          # Respond to Discord PING request
+          render json: { type: 1 }
+        else
+          response = { type: 5, data: { content: "Searching..." } }
+          hijack { render json: response }
+
+          pp request.headers
+          pp body
+
+          # Respond to /commands
+          persona = DiscourseAi::AiBot::Personas::DiscourseHelper
+          bot =
+            DiscourseAi::AiBot::Bot.as(
+              Discourse.system_user,
+              persona: persona.new,
+              model: "custom:6",
+            )
+
+          query = body["data"]["options"].first["value"]
+          reply = ""
+          reply =
+            bot.reply({ conversation_context: [{ type: :user, content: query }] }) { |a, b, c| nil }
+
+          pp reply.last.first
+
+          discord_reply = reply.last.first
+
+          api_endpoint =
+            "https://discord.com/api/webhooks/#{SiteSetting.ai_discord_app_id}/#{body["token"]}"
+
+          conn = Faraday.new { |f| f.adapter FinalDestination::FaradayAdapter }
+          response =
+            conn.post(
+              api_endpoint,
+              { content: discord_reply }.to_json,
+              { "Content-Type" => "application/json" },
+            )
+
+          pp response
+        end
+      end
+
+      private
+
+      def verify_request!
+        signature = request.headers["X-Signature-Ed25519"]
+        timestamp = request.headers["X-Signature-Timestamp"]
+        verify_key.verify([signature].pack("H*"), "#{timestamp}#{request.raw_post}")
+      end
+
+      def verify_key
+        # TODO remove this gem dependency
+        Ed25519::VerifyKey.new([SiteSetting.ai_discord_app_public_key].pack("H*")).freeze
+      end
+    end
+  end
+end

config/routes.rb

@@ -15,6 +15,10 @@
     get "quick-search" => "embeddings#quick_search"
   end
 
+  scope module: :discord, path: "/discord", defaults: { format: :json } do
+    post "interactions" => "bot#interactions"
+  end
+
   scope module: :ai_bot, path: "/ai-bot", defaults: { format: :json } do
     get "bot-username" => "bot#show_bot_username"
     get "post/:post_id/show-debug-info" => "bot#show_debug_info"

config/settings.yml

@@ -431,3 +431,10 @@ discourse_ai:
     hidden: true
     type: list
     list_type: compact
+
+  ai_discord_app_id:
+    default: ""
+    client: false
+  ai_discord_app_public_key:
+    default: ""
+    client: false

plugin.rb

@@ -10,6 +10,7 @@
 
 gem "tokenizers", "0.4.4"
 gem "tiktoken_ruby", "0.0.9"
+gem "ed25519", "1.2.4" #TODO remove this as existing ssl gem should handle this
 
 enabled_site_setting :discourse_ai_enabled