Refactor code structure for improved readability and maintainability

memory_gateway/backend_ref_mapping.py

@@ -0,0 +1,66 @@
+"""Backend-specific ref type mapping for Memory Gateway v2."""
+from __future__ import annotations
+
+from .schemas_v2 import BackendType, MemoryRefType
+
+
+OPENVIKING_REF_TYPE_MAP = {
+    "session_archive": MemoryRefType.SESSION_ARCHIVE,
+    "context_resource": MemoryRefType.CONTEXT_RESOURCE,
+    "resource": MemoryRefType.CONTEXT_RESOURCE,
+    "session_summary": MemoryRefType.SESSION_ARCHIVE,
+}
+
+EVERMEMOS_REF_TYPE_MAP = {
+    "message_memory": MemoryRefType.MESSAGE_MEMORY,
+    "episodic_memory": MemoryRefType.EPISODIC_MEMORY,
+    "episode": MemoryRefType.EPISODIC_MEMORY,
+    "profile": MemoryRefType.PROFILE,
+    "long_term_memory": MemoryRefType.LONG_TERM_MEMORY,
+    "memory": MemoryRefType.LONG_TERM_MEMORY,
+    "preference": MemoryRefType.PROFILE,
+}
+
+OBSIDIAN_REF_TYPE_MAP = {
+    "review_draft": MemoryRefType.DRAFT_REVIEW,
+    "draft_review": MemoryRefType.DRAFT_REVIEW,
+}
+
+
+def map_backend_ref_type(
+    backend_type: BackendType,
+    backend_ref_type: str | None,
+) -> tuple[MemoryRefType, dict[str, str]]:
+    """Map backend-native ref type to a Gateway MemoryRefType.
+
+    Unknown values fall back to a backend-appropriate default and preserve the
+    original value in returned metadata for later inspection.
+    """
+    raw_type = (backend_ref_type or "").strip()
+    normalized = raw_type.lower()
+
+    if backend_type == BackendType.OPENVIKING:
+        mapped = OPENVIKING_REF_TYPE_MAP.get(normalized, MemoryRefType.SESSION_ARCHIVE)
+    elif backend_type == BackendType.EVERMEMOS:
+        mapped = EVERMEMOS_REF_TYPE_MAP.get(normalized, MemoryRefType.LONG_TERM_MEMORY)
+    elif backend_type == BackendType.OBSIDIAN:
+        mapped = OBSIDIAN_REF_TYPE_MAP.get(normalized, MemoryRefType.DRAFT_REVIEW)
+    else:
+        mapped = MemoryRefType.LONG_TERM_MEMORY
+
+    metadata: dict[str, str] = {}
+    if raw_type and raw_type not in {mapped.value, normalized}:
+        metadata["original_ref_type"] = raw_type
+    elif raw_type and normalized not in _known_backend_ref_types(backend_type):
+        metadata["original_ref_type"] = raw_type
+    return mapped, metadata
+
+
+def _known_backend_ref_types(backend_type: BackendType) -> set[str]:
+    if backend_type == BackendType.OPENVIKING:
+        return set(OPENVIKING_REF_TYPE_MAP)
+    if backend_type == BackendType.EVERMEMOS:
+        return set(EVERMEMOS_REF_TYPE_MAP)
+    if backend_type == BackendType.OBSIDIAN:
+        return set(OBSIDIAN_REF_TYPE_MAP)
+    return set()