FIX: streaming broken in bedrock when chunks are not aligned (#609)

Also

- Stop caching llm list - this cause llm list in persona to be incorrect
- Add more UI to debug screen so you can properly see raw response

assets/javascripts/discourse/components/modal/debug-ai-modal.gjs

@@ -1,5 +1,6 @@
 import Component from "@glimmer/component";
 import { tracked } from "@glimmer/tracking";
+import { on } from "@ember/modifier";
 import { action } from "@ember/object";
 import { next } from "@ember/runloop";
 import { htmlSafe } from "@ember/template";
@@ -14,6 +15,7 @@ import I18n from "discourse-i18n";
 export default class DebugAiModal extends Component {
   @tracked info = null;
   @tracked justCopiedText = "";
+  @tracked activeTab = "request";
 
   constructor() {
     super(...arguments);
@@ -30,7 +32,11 @@ export default class DebugAiModal extends Component {
     let parsed;
 
     try {
+      if (this.activeTab === "request") {
         parsed = JSON.parse(this.info.raw_request_payload);
+      } else {
+        return this.formattedResponse(this.info.raw_response_payload);
+      }
     } catch (e) {
       return this.info.raw_request_payload;
     }
@@ -38,6 +44,14 @@ export default class DebugAiModal extends Component {
     return htmlSafe(this.jsonToHtml(parsed));
   }
 
+  formattedResponse(response) {
+    // we need to replace the new lines with <br> to make it look good
+    const split = response.split("\n");
+    const safe = split.map((line) => escapeExpression(line)).join("<br>");
+
+    return htmlSafe(safe);
+  }
+
   jsonToHtml(json) {
     let html = "<ul>";
     for (let key in json) {
@@ -94,6 +108,26 @@ export default class DebugAiModal extends Component {
     });
   }
 
+  get requestActive() {
+    return this.activeTab === "request" ? "active" : "";
+  }
+
+  get responseActive() {
+    return this.activeTab === "response" ? "active" : "";
+  }
+
+  @action
+  requestClicked(e) {
+    this.activeTab = "request";
+    e.preventDefault();
+  }
+
+  @action
+  responseClicked(e) {
+    this.activeTab = "response";
+    e.preventDefault();
+  }
+
   <template>
     <DModal
       class="ai-debug-modal"
@@ -101,6 +135,18 @@ export default class DebugAiModal extends Component {
       @closeModal={{@closeModal}}
     >
       <:body>
+        <ul class="nav nav-pills ai-debug-modal__nav">
+          <li><a
+              href=""
+              class={{this.requestActive}}
+              {{on "click" this.requestClicked}}
+            >{{i18n "discourse_ai.ai_bot.debug_ai_modal.request"}}</a></li>
+          <li><a
+              href=""
+              class={{this.responseActive}}
+              {{on "click" this.responseClicked}}
+            >{{i18n "discourse_ai.ai_bot.debug_ai_modal.response"}}</a></li>
+        </ul>
         <div class="ai-debug-modal__tokens">
           <span>
             {{i18n "discourse_ai.ai_bot.debug_ai_modal.request_tokens"}}

assets/stylesheets/modules/ai-bot/common/bot-replies.scss

@@ -161,3 +161,9 @@ span.onebox-ai-llm-title {
 .ai-debug-modal__tokens span {
   display: block;
 }
+
+.d-modal ul.ai-debug-modal__nav {
+  margin: 0 0 1em;
+  padding: 0;
+  border-bottom: none;
+}

config/locales/client.en.yml

@@ -271,6 +271,8 @@ en:
           copy_response: "Copy response"
           request_tokens: "Request tokens:"
           response_tokens: "Response tokens:"
+          request: "Request"
+          response: "Response"
 
         share_full_topic_modal:
           title: "Share Conversation Publicly"

lib/completions/endpoints/aws_bedrock.rb

@@ -111,23 +111,30 @@ module DiscourseAi
         end
 
         def decode(chunk)
-          parsed =
-            Aws::EventStream::Decoder
-              .new
-              .decode_chunk(chunk)
-              .first
-              .payload
-              .string
-              .then { JSON.parse(_1) }
+          @decoder ||= Aws::EventStream::Decoder.new
 
-          bytes = parsed.dig("bytes")
+          decoded, _done = @decoder.decode_chunk(chunk)
 
-          if !bytes
-            Rails.logger.error("#{self.class.name}: #{parsed.to_s[0..500]}")
-            nil
-          else
-            Base64.decode64(parsed.dig("bytes"))
+          messages = []
+          return messages if !decoded
+
+          i = 0
+          while decoded
+            parsed = JSON.parse(decoded.payload.string)
+            messages << Base64.decode64(parsed["bytes"])
+
+            decoded, _done = @decoder.decode_chunk
+
+            i += 1
+            if i > 10_000
+              Rails.logger.error(
+                "DiscourseAI: Stream decoder looped too many times, logic error needs fixing",
+              )
+              break
             end
+          end
+
+          messages
         rescue JSON::ParserError,
                Aws::EventStream::Errors::MessageChecksumError,
                Aws::EventStream::Errors::PreludeChecksumError => e
@@ -161,8 +168,14 @@ module DiscourseAi
           result
         end
 
-        def partials_from(decoded_chunk)
-          [decoded_chunk]
+        def partials_from(decoded_chunks)
+          decoded_chunks
+        end
+
+        def chunk_to_string(chunk)
+          joined = +chunk.join("\n")
+          joined << "\n" if joined.length > 0
+          joined
         end
       end
     end

lib/completions/endpoints/base.rb

@@ -168,9 +168,15 @@ module DiscourseAi
                   if decoded_chunk.nil?
                     raise CompletionFailed, "#{self.class.name}: Failed to decode LLM completion"
                   end
-                  response_raw << decoded_chunk
+                  response_raw << chunk_to_string(decoded_chunk)
 
+                  if decoded_chunk.is_a?(String)
                     redo_chunk = leftover + decoded_chunk
+                  else
+                    # custom implementation for endpoint
+                    # no implicit leftover support
+                    redo_chunk = decoded_chunk
+                  end
 
                   raw_partials = partials_from(redo_chunk)
 
@@ -347,6 +353,14 @@ module DiscourseAi
           response.include?("<function_calls>")
         end
 
+        def chunk_to_string(chunk)
+          if chunk.is_a?(String)
+            chunk
+          else
+            chunk.to_s
+          end
+        end
+
         def add_to_function_buffer(function_buffer, partial: nil, payload: nil)
           if payload&.include?("</invoke>")
             matches = payload.match(%r{<function_calls>.*</invoke>}m)

lib/completions/endpoints/cohere.rb

@@ -26,9 +26,7 @@ module DiscourseAi
 
         def normalize_model_params(model_params)
           model_params = model_params.dup
-
           model_params[:p] = model_params.delete(:top_p) if model_params[:top_p]
-
           model_params
         end
 

lib/configuration/llm_enumerator.rb

@@ -10,7 +10,7 @@ module DiscourseAi
       end
 
       def self.values
-        @values ||=
+        # do not cache cause settings can change this
         DiscourseAi::Completions::Llm.models_by_provider.flat_map do |provider, models|
           endpoint =
             DiscourseAi::Completions::Endpoints::Base.endpoint_for(provider.to_s, models.first)

spec/lib/completions/endpoints/aws_bedrock_spec.rb

@@ -86,6 +86,10 @@ RSpec.describe DiscourseAi::Completions::Endpoints::AwsBedrock do
           Aws::EventStream::Encoder.new.encode(aws_message)
         end
 
+      # stream 1 letter at a time
+      # cause we need to handle this case
+      messages = messages.join("").split
+
       bedrock_mock.with_chunk_array_support do
         stub_request(
           :post,