Fixed text loader to use librarian as a source

trustgraph-flow/trustgraph/chunking/token/chunker.py

@@ -4,18 +4,28 @@ Simple decoder, accepts text documents on input, outputs chunks from the
 as text as separate output objects.
 """
 
+import asyncio
+import base64
 import logging
+import uuid
 from langchain_text_splitters import TokenTextSplitter
 from prometheus_client import Histogram
 
 from ... schema import TextDocument, Chunk
+from ... schema import LibrarianRequest, LibrarianResponse
+from ... schema import librarian_request_queue, librarian_response_queue
 from ... base import ChunkingService, ConsumerSpec, ProducerSpec
+from ... base import Consumer, Producer, ConsumerMetrics, ProducerMetrics
 
 # Module logger
 logger = logging.getLogger(__name__)
 
 default_ident = "chunker"
 
+default_librarian_request_queue = librarian_request_queue
+default_librarian_response_queue = librarian_response_queue
+
+
 class Processor(ChunkingService):
 
     def __init__(self, **params):
@@ -61,13 +71,117 @@ class Processor(ChunkingService):
             )
         )
 
+        # Librarian client for fetching document content
+        librarian_request_q = params.get(
+            "librarian_request_queue", default_librarian_request_queue
+        )
+        librarian_response_q = params.get(
+            "librarian_response_queue", default_librarian_response_queue
+        )
+
+        librarian_request_metrics = ProducerMetrics(
+            processor = id, flow = None, name = "librarian-request"
+        )
+
+        self.librarian_request_producer = Producer(
+            backend = self.pubsub,
+            topic = librarian_request_q,
+            schema = LibrarianRequest,
+            metrics = librarian_request_metrics,
+        )
+
+        librarian_response_metrics = ConsumerMetrics(
+            processor = id, flow = None, name = "librarian-response"
+        )
+
+        self.librarian_response_consumer = Consumer(
+            taskgroup = self.taskgroup,
+            backend = self.pubsub,
+            flow = None,
+            topic = librarian_response_q,
+            subscriber = f"{id}-librarian",
+            schema = LibrarianResponse,
+            handler = self.on_librarian_response,
+            metrics = librarian_response_metrics,
+        )
+
+        # Pending librarian requests: request_id -> asyncio.Future
+        self.pending_requests = {}
+
         logger.info("Token chunker initialized")
 
+    async def start(self):
+        await super(Processor, self).start()
+        await self.librarian_request_producer.start()
+        await self.librarian_response_consumer.start()
+
+    async def on_librarian_response(self, msg, consumer, flow):
+        """Handle responses from the librarian service."""
+        response = msg.value()
+        request_id = msg.properties().get("id")
+
+        if request_id and request_id in self.pending_requests:
+            future = self.pending_requests.pop(request_id)
+            future.set_result(response)
+        else:
+            logger.warning(f"Received unexpected librarian response: {request_id}")
+
+    async def fetch_document_content(self, document_id, user, timeout=120):
+        """
+        Fetch document content from librarian via Pulsar.
+        """
+        request_id = str(uuid.uuid4())
+
+        request = LibrarianRequest(
+            operation="get-document-content",
+            document_id=document_id,
+            user=user,
+        )
+
+        # Create future for response
+        future = asyncio.get_event_loop().create_future()
+        self.pending_requests[request_id] = future
+
+        try:
+            # Send request
+            await self.librarian_request_producer.send(
+                request, properties={"id": request_id}
+            )
+
+            # Wait for response
+            response = await asyncio.wait_for(future, timeout=timeout)
+
+            if response.error:
+                raise RuntimeError(
+                    f"Librarian error: {response.error.type}: {response.error.message}"
+                )
+
+            return response.content
+
+        except asyncio.TimeoutError:
+            self.pending_requests.pop(request_id, None)
+            raise RuntimeError(f"Timeout fetching document {document_id}")
+
     async def on_message(self, msg, consumer, flow):
 
         v = msg.value()
         logger.info(f"Chunking document {v.metadata.id}...")
 
+        # Check if we need to fetch content from librarian
+        if v.document_id and not v.text:
+            logger.info(f"Fetching document {v.document_id} from librarian...")
+            content = await self.fetch_document_content(
+                document_id=v.document_id,
+                user=v.metadata.user,
+            )
+            # Content is base64 encoded
+            if isinstance(content, str):
+                content = content.encode('utf-8')
+            text = base64.b64decode(content).decode("utf-8")
+            logger.info(f"Fetched {len(text)} characters from librarian")
+        else:
+            text = v.text.decode("utf-8")
+
         # Extract chunk parameters from flow (allows runtime override)
         chunk_size, chunk_overlap = await self.chunk_document(
             msg, consumer, flow,
@@ -88,9 +202,7 @@ class Processor(ChunkingService):
             chunk_overlap=chunk_overlap,
         )
 
-        texts = text_splitter.create_documents(
-            [v.text.decode("utf-8")]
-        )
+        texts = text_splitter.create_documents([text])
 
         for ix, chunk in enumerate(texts):
 
@@ -128,6 +240,18 @@ class Processor(ChunkingService):
             help=f'Chunk overlap (default: 15)'
         )
 
+        parser.add_argument(
+            '--librarian-request-queue',
+            default=default_librarian_request_queue,
+            help=f'Librarian request queue (default: {default_librarian_request_queue})',
+        )
+
+        parser.add_argument(
+            '--librarian-response-queue',
+            default=default_librarian_response_queue,
+            help=f'Librarian response queue (default: {default_librarian_response_queue})',
+        )
+
 def run():
 
     Processor.launch(default_ident, __doc__)