feat(settings): add multi-library backend support

py/services/settings_manager.py

@@ -1,7 +1,9 @@
+import copy
 import json
 import os
 import logging
-from typing import Any, Dict
+from datetime import datetime
+from typing import Any, Dict, Iterable, List, Mapping, Optional
 
 from ..utils.settings_paths import ensure_settings_file
 
@@ -42,6 +44,7 @@ class SettingsManager:
         self.settings = self._load_settings()
         self._migrate_setting_keys()
         self._ensure_default_settings()
+        self._migrate_to_library_registry()
         self._migrate_download_path_template()
         self._auto_set_default_roots()
         self._check_environment_variables()
@@ -69,6 +72,223 @@ class SettingsManager:
         if updated:
             self._save_settings()
 
+    def _migrate_to_library_registry(self) -> None:
+        """Ensure settings include the multi-library registry structure."""
+        libraries = self.settings.get("libraries")
+        active_name = self.settings.get("active_library")
+
+        if not isinstance(libraries, dict) or not libraries:
+            library_name = active_name or "default"
+            library_payload = self._build_library_payload(
+                folder_paths=self.settings.get("folder_paths", {}),
+                default_lora_root=self.settings.get("default_lora_root", ""),
+                default_checkpoint_root=self.settings.get("default_checkpoint_root", ""),
+                default_embedding_root=self.settings.get("default_embedding_root", ""),
+            )
+            libraries = {library_name: library_payload}
+            self.settings["libraries"] = libraries
+            self.settings["active_library"] = library_name
+            self._sync_active_library_to_root(save=False)
+            self._save_settings()
+            return
+
+        sanitized_libraries: Dict[str, Dict[str, Any]] = {}
+        changed = False
+        for name, data in libraries.items():
+            if not isinstance(data, dict):
+                data = {}
+                changed = True
+            payload = self._build_library_payload(
+                folder_paths=data.get("folder_paths"),
+                default_lora_root=data.get("default_lora_root"),
+                default_checkpoint_root=data.get("default_checkpoint_root"),
+                default_embedding_root=data.get("default_embedding_root"),
+                metadata=data.get("metadata"),
+                base=data,
+            )
+            sanitized_libraries[name] = payload
+            if payload is not data:
+                changed = True
+
+        if changed:
+            self.settings["libraries"] = sanitized_libraries
+
+        if not active_name or active_name not in sanitized_libraries:
+            if sanitized_libraries:
+                self.settings["active_library"] = next(iter(sanitized_libraries.keys()))
+            else:
+                self.settings["active_library"] = "default"
+
+        self._sync_active_library_to_root(save=changed)
+
+    def _sync_active_library_to_root(self, *, save: bool = False) -> None:
+        """Update top-level folder path settings to mirror the active library."""
+        libraries = self.settings.get("libraries", {})
+        active_name = self.settings.get("active_library")
+        if not libraries:
+            return
+
+        if active_name not in libraries:
+            active_name = next(iter(libraries.keys()))
+            self.settings["active_library"] = active_name
+
+        active_library = libraries.get(active_name, {})
+        folder_paths = copy.deepcopy(active_library.get("folder_paths", {}))
+        self.settings["folder_paths"] = folder_paths
+        self.settings["default_lora_root"] = active_library.get("default_lora_root", "")
+        self.settings["default_checkpoint_root"] = active_library.get("default_checkpoint_root", "")
+        self.settings["default_embedding_root"] = active_library.get("default_embedding_root", "")
+
+        if save:
+            self._save_settings()
+
+    def _current_timestamp(self) -> str:
+        return datetime.utcnow().replace(microsecond=0).isoformat() + "Z"
+
+    def _build_library_payload(
+        self,
+        *,
+        folder_paths: Optional[Mapping[str, Iterable[str]]] = None,
+        default_lora_root: Optional[str] = None,
+        default_checkpoint_root: Optional[str] = None,
+        default_embedding_root: Optional[str] = None,
+        metadata: Optional[Mapping[str, Any]] = None,
+        base: Optional[Mapping[str, Any]] = None,
+    ) -> Dict[str, Any]:
+        payload: Dict[str, Any] = dict(base or {})
+        timestamp = self._current_timestamp()
+
+        if folder_paths is not None:
+            payload["folder_paths"] = self._normalize_folder_paths(folder_paths)
+        else:
+            payload.setdefault("folder_paths", {})
+
+        if default_lora_root is not None:
+            payload["default_lora_root"] = default_lora_root
+        else:
+            payload.setdefault("default_lora_root", "")
+
+        if default_checkpoint_root is not None:
+            payload["default_checkpoint_root"] = default_checkpoint_root
+        else:
+            payload.setdefault("default_checkpoint_root", "")
+
+        if default_embedding_root is not None:
+            payload["default_embedding_root"] = default_embedding_root
+        else:
+            payload.setdefault("default_embedding_root", "")
+
+        if metadata:
+            merged_meta = dict(payload.get("metadata", {}))
+            merged_meta.update(metadata)
+            payload["metadata"] = merged_meta
+
+        payload.setdefault("created_at", timestamp)
+        payload["updated_at"] = timestamp
+        return payload
+
+    def _normalize_folder_paths(
+        self, folder_paths: Mapping[str, Iterable[str]]
+    ) -> Dict[str, List[str]]:
+        normalized: Dict[str, List[str]] = {}
+        for key, values in folder_paths.items():
+            if not isinstance(values, Iterable):
+                continue
+            cleaned: List[str] = []
+            seen = set()
+            for value in values:
+                if not isinstance(value, str):
+                    continue
+                stripped = value.strip()
+                if not stripped:
+                    continue
+                if stripped not in seen:
+                    cleaned.append(stripped)
+                    seen.add(stripped)
+            normalized[key] = cleaned
+        return normalized
+
+    def _validate_folder_paths(
+        self,
+        library_name: str,
+        folder_paths: Mapping[str, Iterable[str]],
+    ) -> None:
+        """Ensure folder paths do not overlap with other libraries."""
+        libraries = self.settings.get("libraries", {})
+        normalized_new: Dict[str, Dict[str, str]] = {}
+        for key, values in folder_paths.items():
+            path_map: Dict[str, str] = {}
+            for value in values:
+                if not isinstance(value, str):
+                    continue
+                stripped = value.strip()
+                if not stripped:
+                    continue
+                normalized_value = os.path.normcase(os.path.normpath(stripped))
+                path_map[normalized_value] = stripped
+            if path_map:
+                normalized_new[key] = path_map
+
+        if not normalized_new:
+            return
+
+        for other_name, other in libraries.items():
+            if other_name == library_name:
+                continue
+            other_paths = other.get("folder_paths", {})
+            for key, new_paths in normalized_new.items():
+                existing = {
+                    os.path.normcase(os.path.normpath(path))
+                    for path in other_paths.get(key, [])
+                    if isinstance(path, str) and path
+                }
+                overlap = existing.intersection(new_paths.keys())
+                if overlap:
+                    collisions = ", ".join(sorted(new_paths[value] for value in overlap))
+                    raise ValueError(
+                        f"Folder path(s) {collisions} already assigned to library '{other_name}'"
+                    )
+
+    def _update_active_library_entry(
+        self,
+        *,
+        folder_paths: Optional[Mapping[str, Iterable[str]]] = None,
+        default_lora_root: Optional[str] = None,
+        default_checkpoint_root: Optional[str] = None,
+        default_embedding_root: Optional[str] = None,
+    ) -> bool:
+        libraries = self.settings.get("libraries", {})
+        active_name = self.settings.get("active_library")
+        if not active_name or active_name not in libraries:
+            return False
+
+        library = libraries[active_name]
+        changed = False
+
+        if folder_paths is not None:
+            normalized_paths = self._normalize_folder_paths(folder_paths)
+            if library.get("folder_paths") != normalized_paths:
+                library["folder_paths"] = normalized_paths
+                changed = True
+
+        if default_lora_root is not None and library.get("default_lora_root") != default_lora_root:
+            library["default_lora_root"] = default_lora_root
+            changed = True
+
+        if default_checkpoint_root is not None and library.get("default_checkpoint_root") != default_checkpoint_root:
+            library["default_checkpoint_root"] = default_checkpoint_root
+            changed = True
+
+        if default_embedding_root is not None and library.get("default_embedding_root") != default_embedding_root:
+            library["default_embedding_root"] = default_embedding_root
+            changed = True
+
+        if changed:
+            library.setdefault("created_at", self._current_timestamp())
+            library["updated_at"] = self._current_timestamp()
+
+        return changed
+
     def _migrate_setting_keys(self) -> None:
         """Migrate legacy camelCase setting keys to snake_case"""
         key_migrations = {
@@ -138,6 +358,11 @@ class SettingsManager:
                 self.settings['default_embedding_root'] = embeddings[0]
                 updated = True
         if updated:
+            self._update_active_library_entry(
+                default_lora_root=self.settings.get('default_lora_root'),
+                default_checkpoint_root=self.settings.get('default_checkpoint_root'),
+                default_embedding_root=self.settings.get('default_embedding_root'),
+            )
             self._save_settings()
 
     def _check_environment_variables(self) -> None:
@@ -168,6 +393,14 @@ class SettingsManager:
     def set(self, key: str, value: Any) -> None:
         """Set setting value and save"""
         self.settings[key] = value
+        if key == 'folder_paths' and isinstance(value, Mapping):
+            self._update_active_library_entry(folder_paths=value)  # type: ignore[arg-type]
+        elif key == 'default_lora_root':
+            self._update_active_library_entry(default_lora_root=str(value))
+        elif key == 'default_checkpoint_root':
+            self._update_active_library_entry(default_checkpoint_root=str(value))
+        elif key == 'default_embedding_root':
+            self._update_active_library_entry(default_embedding_root=str(value))
         self._save_settings()
 
     def delete(self, key: str) -> None:
@@ -185,6 +418,227 @@ class SettingsManager:
         except Exception as e:
             logger.error(f"Error saving settings: {e}")
 
+    def get_libraries(self) -> Dict[str, Dict[str, Any]]:
+        """Return a copy of the registered libraries."""
+        libraries = self.settings.get("libraries", {})
+        return copy.deepcopy(libraries)
+
+    def get_active_library_name(self) -> str:
+        """Return the currently active library name."""
+        libraries = self.settings.get("libraries", {})
+        active_name = self.settings.get("active_library")
+        if active_name and active_name in libraries:
+            return active_name
+        if libraries:
+            return next(iter(libraries.keys()))
+        return "default"
+
+    def get_active_library(self) -> Dict[str, Any]:
+        """Return a copy of the active library configuration."""
+        libraries = self.settings.get("libraries", {})
+        active_name = self.get_active_library_name()
+        return copy.deepcopy(libraries.get(active_name, {}))
+
+    def activate_library(self, library_name: str) -> None:
+        """Activate a library by name and refresh dependent services."""
+        libraries = self.settings.get("libraries", {})
+        if library_name not in libraries:
+            raise KeyError(f"Library '{library_name}' does not exist")
+
+        current_active = self.get_active_library_name()
+        if current_active == library_name:
+            # Ensure root settings stay in sync even if already active
+            self._sync_active_library_to_root(save=False)
+            self._save_settings()
+            self._notify_library_change(library_name)
+            return
+
+        self.settings["active_library"] = library_name
+        self._sync_active_library_to_root(save=False)
+        self._save_settings()
+        self._notify_library_change(library_name)
+
+    def upsert_library(
+        self,
+        library_name: str,
+        *,
+        folder_paths: Optional[Mapping[str, Iterable[str]]] = None,
+        default_lora_root: Optional[str] = None,
+        default_checkpoint_root: Optional[str] = None,
+        default_embedding_root: Optional[str] = None,
+        metadata: Optional[Mapping[str, Any]] = None,
+        activate: bool = False,
+    ) -> Dict[str, Any]:
+        """Create or update a library definition."""
+
+        name = library_name.strip()
+        if not name:
+            raise ValueError("Library name cannot be empty")
+
+        if folder_paths is not None:
+            self._validate_folder_paths(name, folder_paths)
+
+        libraries = self.settings.setdefault("libraries", {})
+        existing = libraries.get(name, {})
+
+        payload = self._build_library_payload(
+            folder_paths=folder_paths if folder_paths is not None else existing.get("folder_paths"),
+            default_lora_root=default_lora_root if default_lora_root is not None else existing.get("default_lora_root"),
+            default_checkpoint_root=(
+                default_checkpoint_root
+                if default_checkpoint_root is not None
+                else existing.get("default_checkpoint_root")
+            ),
+            default_embedding_root=(
+                default_embedding_root
+                if default_embedding_root is not None
+                else existing.get("default_embedding_root")
+            ),
+            metadata=metadata if metadata is not None else existing.get("metadata"),
+            base=existing,
+        )
+
+        libraries[name] = payload
+
+        if activate or not self.settings.get("active_library"):
+            self.settings["active_library"] = name
+
+        self._sync_active_library_to_root(save=False)
+        self._save_settings()
+
+        if self.settings.get("active_library") == name:
+            self._notify_library_change(name)
+
+        return payload
+
+    def create_library(
+        self,
+        library_name: str,
+        *,
+        folder_paths: Mapping[str, Iterable[str]],
+        default_lora_root: str = "",
+        default_checkpoint_root: str = "",
+        default_embedding_root: str = "",
+        metadata: Optional[Mapping[str, Any]] = None,
+        activate: bool = False,
+    ) -> Dict[str, Any]:
+        """Create a new library entry."""
+
+        libraries = self.settings.get("libraries", {})
+        if library_name in libraries:
+            raise ValueError(f"Library '{library_name}' already exists")
+
+        return self.upsert_library(
+            library_name,
+            folder_paths=folder_paths,
+            default_lora_root=default_lora_root,
+            default_checkpoint_root=default_checkpoint_root,
+            default_embedding_root=default_embedding_root,
+            metadata=metadata,
+            activate=activate,
+        )
+
+    def rename_library(self, old_name: str, new_name: str) -> None:
+        """Rename an existing library."""
+
+        libraries = self.settings.get("libraries", {})
+        if old_name not in libraries:
+            raise KeyError(f"Library '{old_name}' does not exist")
+        new_name_stripped = new_name.strip()
+        if not new_name_stripped:
+            raise ValueError("New library name cannot be empty")
+        if new_name_stripped in libraries:
+            raise ValueError(f"Library '{new_name_stripped}' already exists")
+
+        libraries[new_name_stripped] = libraries.pop(old_name)
+        if self.settings.get("active_library") == old_name:
+            self.settings["active_library"] = new_name_stripped
+            active_name = new_name_stripped
+        else:
+            active_name = self.settings.get("active_library")
+
+        self._sync_active_library_to_root(save=False)
+        self._save_settings()
+
+        if active_name == new_name_stripped:
+            self._notify_library_change(new_name_stripped)
+
+    def delete_library(self, library_name: str) -> None:
+        """Remove a library definition."""
+
+        libraries = self.settings.get("libraries", {})
+        if library_name not in libraries:
+            raise KeyError(f"Library '{library_name}' does not exist")
+        if len(libraries) == 1:
+            raise ValueError("At least one library must remain")
+
+        was_active = self.settings.get("active_library") == library_name
+        libraries.pop(library_name)
+
+        if was_active:
+            new_active = next(iter(libraries.keys()))
+            self.settings["active_library"] = new_active
+        self._sync_active_library_to_root(save=False)
+        self._save_settings()
+
+        if was_active:
+            self._notify_library_change(self.settings["active_library"])
+
+    def update_active_library_paths(
+        self,
+        folder_paths: Mapping[str, Iterable[str]],
+        *,
+        default_lora_root: Optional[str] = None,
+        default_checkpoint_root: Optional[str] = None,
+        default_embedding_root: Optional[str] = None,
+    ) -> None:
+        """Update folder paths for the active library."""
+
+        active_name = self.get_active_library_name()
+        self.upsert_library(
+            active_name,
+            folder_paths=folder_paths,
+            default_lora_root=default_lora_root,
+            default_checkpoint_root=default_checkpoint_root,
+            default_embedding_root=default_embedding_root,
+            activate=True,
+        )
+
+    def _notify_library_change(self, library_name: str) -> None:
+        """Notify dependent services that the active library changed."""
+        libraries = self.settings.get("libraries", {})
+        library_config = libraries.get(library_name, {})
+        library_snapshot = copy.deepcopy(library_config)
+
+        try:
+            from ..config import config  # Local import to avoid circular dependency
+
+            config.apply_library_settings(library_snapshot)
+        except Exception as exc:  # pragma: no cover - defensive logging
+            logger.debug("Failed to apply library settings to config: %s", exc)
+
+        try:
+            from .service_registry import ServiceRegistry  # type: ignore
+
+            for service_name in (
+                "lora_scanner",
+                "checkpoint_scanner",
+                "embedding_scanner",
+                "recipe_scanner",
+            ):
+                service = ServiceRegistry.get_service_sync(service_name)
+                if service and hasattr(service, "on_library_changed"):
+                    try:
+                        service.on_library_changed()
+                    except Exception as service_exc:  # pragma: no cover - defensive logging
+                        logger.debug(
+                            "Service %s failed to handle library change: %s",
+                            service_name,
+                            service_exc,
+                        )
+        except Exception as exc:  # pragma: no cover - defensive logging
+            logger.debug("Failed to notify services about library change: %s", exc)
+
     def get_download_path_template(self, model_type: str) -> str:
         """Get download path template for specific model type