add knowledge_writer

src/basic_memory/markdown/knowledge_writer.py

@@ -0,0 +1,73 @@
+"""Writer for knowledge entity markdown files."""
+
+from datetime import datetime, UTC
+from typing import Optional, Dict, Any
+
+import yaml
+from loguru import logger
+
+from basic_memory.models import Entity as EntityModel
+
+
+class KnowledgeWriter:
+    """Formats entities into markdown files."""
+
+    async def format_frontmatter(self, entity: EntityModel) -> dict:
+        """Generate frontmatter metadata for entity."""
+        now = datetime.now(UTC).isoformat()
+        return {
+            "type": entity.entity_type,
+            "id": entity.id,
+            "created": now,
+            "modified": now
+        }
+
+    async def format_metadata(self, metadata: Optional[Dict[str, Any]] = None) -> str:
+        """Format metadata section as YAML block."""
+        if not metadata:
+            return ""
+
+        try:
+            yaml_block = yaml.dump(metadata, sort_keys=False)
+            return (
+                "# Metadata\n"
+                "<!-- anything below this line is for AI -->\n\n"
+                "```yml\n"
+                f"{yaml_block}"
+                "```\n"
+            )
+        except Exception as e:
+            logger.warning(f"Failed to format metadata YAML: {e}")
+            return ""  # Skip metadata on error
+
+    async def format_content(self, entity: EntityModel, metadata: Optional[Dict[str, Any]] = None) -> str:
+        """Format entity content as markdown."""
+        sections = [
+            f"# {entity.name}\n"
+        ]
+
+        if entity.description:
+            sections.extend([
+                entity.description,
+                ""
+            ])
+            
+        if entity.observations:
+            sections.extend([
+                "## Observations",
+                *[f"- {obs.content}" for obs in entity.observations],
+                ""
+            ])
+
+        if entity.relations:
+            sections.extend([
+                "## Relations",
+                *[f"- [[{rel.to_entity.name}]] {rel.relation_type}" for rel in entity.relations],
+                ""
+            ])
+
+        if metadata:
+            sections.append("\n")
+            sections.append(await self.format_metadata(metadata))
+
+        return "\n".join(sections)

src/basic_memory/services/knowledge_service.py

@@ -10,6 +10,7 @@ from basic_memory.models import Entity as EntityModel
 from basic_memory.schemas import Entity as EntitySchema, Relation as RelationSchema
 from basic_memory.services.entity_service import EntityService
 from basic_memory.services.exceptions import EntityNotFoundError, FileOperationError
+from basic_memory.services.file_service import FileService
 from basic_memory.services.observation_service import ObservationService
 from basic_memory.services.relation_service import RelationService
 
@@ -31,7 +32,7 @@ class KnowledgeService:
         entity_service: EntityService,
         observation_service: ObservationService,
         relation_service: RelationService,
-        file_service,  # FileService
+        file_service: FileService,  # FileService
         knowledge_parser: KnowledgeParser,
     ):
         self.entity_service = entity_service