chore: apply backend streaming updates into app

app/(chat)/api/chat/route.ts

@@ -8,11 +8,15 @@ import {
 import { auth } from '@/app/(auth)/auth';
 import { patternProvider } from '@/lib/ai/pattern-provider';
 import { deleteChatById, getChatById } from '@/lib/db/queries';
-import { generateUUID, getMostRecentUserMessage } from '@/lib/utils';
+import {
+  extractErrorMessageOrDefault,
+  generateUUID,
+  getMostRecentUserMessage,
+} from '@/lib/utils';
 
 import { getOrCreateConversation } from '../../service';
 
-export const maxDuration = 60;
+export const maxDuration = 300;
 
 export async function POST(request: Request) {
   const { id, messages }: { id: string; messages: Array<Message> } =
@@ -70,8 +74,8 @@ export async function POST(request: Request) {
         sendReasoning: true,
       });
     },
-    onError: () => {
-      return 'Oops, an error occured!';
+    onError: (error) => {
+      return extractErrorMessageOrDefault(error);
     },
   });
 }

lib/ai/pattern-model.ts

@@ -96,10 +96,19 @@ export class PatternModel implements LanguageModelV1 {
                  * TODO: Re-enable reasoning when backend supports it
                  * https://github.com/pattern-tech/pattern-app/issues/27
                  */
+              } else if (
+                event.type === 'completion' ||
+                event.type === 'heartbeat'
+              ) {
+                /**
+                 * Ignore heartbeat and completion events. Completion event is
+                 * identified automatically when the stream is ended, and the
+                 * heartbeat event is only for keeping the connection alive
+                 */
               } else {
                 controller.enqueue({
                   type: 'error',
-                  error: `Event type is not supported`,
+                  error: `Event type "${(event as unknown as { type: string }).type}" is not supported`,
                 });
               }
             });

lib/ai/types.ts

@@ -9,7 +9,21 @@ export interface ToolStartEvent {
   tool_input: Record<string, string>;
 }
 
-export type PatternStreamingResponseEvent = TokenEvent | ToolStartEvent;
+export interface CompletionEvent {
+  type: 'completion';
+  data: 'Stream completed';
+}
+
+export interface HeartbeatEvent {
+  type: 'heartbeat';
+  data: 'still_processing';
+}
+
+export type PatternStreamingResponseEvent =
+  | TokenEvent
+  | ToolStartEvent
+  | CompletionEvent
+  | HeartbeatEvent;
 
 export interface PatternProviderMetadata {
   accessToken: string;