Enhance LoraScanner and file_utils for improved metadata handling

- Updated LoraScanner to first attempt to create metadata from .civitai.info files, improving metadata extraction from existing files.
- Added error handling for reading .civitai.info files and fallback to generating metadata using get_file_info if necessary.
- Refactored file_utils to expose find_preview_file function and added logic to utilize SHA256 from existing .json files to avoid recalculation.
- Improved overall robustness of metadata loading and preview file retrieval processes.

py/services/lora_scanner.py

@@ -5,10 +5,11 @@ import asyncio
 import shutil
 import time
 from typing import List, Dict, Optional
-from dataclasses import dataclass
-from operator import itemgetter
+
+from ..utils.models import LoraMetadata
 from ..config import config
-from ..utils.file_utils import load_metadata, get_file_info
+from ..utils.file_utils import load_metadata, get_file_info, normalize_path, find_preview_file, save_metadata
+from ..utils.lora_metadata import extract_lora_metadata
 from .lora_cache import LoraCache
 from .lora_hash_index import LoraHashIndex
 from .settings_manager import settings
@@ -332,8 +333,30 @@ class LoraScanner:
         metadata = await load_metadata(file_path)
         
         if metadata is None:
-            # Create new metadata if none exists
-            metadata = await get_file_info(file_path)
+            # Try to find and use .civitai.info file first
+            civitai_info_path = f"{os.path.splitext(file_path)[0]}.civitai.info"
+            if os.path.exists(civitai_info_path):
+                try:
+                    with open(civitai_info_path, 'r', encoding='utf-8') as f:
+                        version_info = json.load(f)
+                    
+                    file_info = next((f for f in version_info.get('files', []) if f.get('primary')), None)
+                    if file_info:
+                        # Create a minimal file_info with the required fields
+                        file_name = os.path.splitext(os.path.basename(file_path))[0]
+                        file_info['name'] = file_name
+                    
+                        # Use from_civitai_info to create metadata
+                        metadata = LoraMetadata.from_civitai_info(version_info, file_info, file_path)
+                        metadata.preview_url = find_preview_file(file_name, os.path.dirname(file_path))
+                        await save_metadata(file_path, metadata)
+                        logger.debug(f"Created metadata from .civitai.info for {file_path}")
+                except Exception as e:
+                    logger.error(f"Error creating metadata from .civitai.info for {file_path}: {e}")
+            
+            # If still no metadata, create new metadata using get_file_info
+            if metadata is None:
+                metadata = await get_file_info(file_path)
         
         # Convert to dict and add folder info
         lora_data = metadata.to_dict()
@@ -344,7 +367,7 @@ class LoraScanner:
         lora_data['folder'] = folder.replace(os.path.sep, '/')
         
         return lora_data
-
+            
     async def _fetch_missing_metadata(self, file_path: str, lora_data: Dict) -> None:
         """Fetch missing description and tags from Civitai if needed
         

py/utils/file_utils.py

@@ -19,7 +19,7 @@ async def calculate_sha256(file_path: str) -> str:
             sha256_hash.update(byte_block)
     return sha256_hash.hexdigest()
 
-def _find_preview_file(base_name: str, dir_path: str) -> str:
+def find_preview_file(base_name: str, dir_path: str) -> str:
     """Find preview file for given base name in directory"""
     preview_patterns = [
         f"{base_name}.preview.png",
@@ -56,16 +56,33 @@ async def get_file_info(file_path: str) -> Optional[LoraMetadata]:
     base_name = os.path.splitext(os.path.basename(file_path))[0]
     dir_path = os.path.dirname(file_path)
     
-    preview_url = _find_preview_file(base_name, dir_path)
+    preview_url = find_preview_file(base_name, dir_path)
+    
+    # Check if a .json file exists with SHA256 hash to avoid recalculation
+    json_path = f"{os.path.splitext(file_path)[0]}.json"
+    sha256 = None
+    if os.path.exists(json_path):
+        try:
+            with open(json_path, 'r', encoding='utf-8') as f:
+                json_data = json.load(f)
+                if 'sha256' in json_data:
+                    sha256 = json_data['sha256'].lower()
+                    logger.debug(f"Using SHA256 from .json file for {file_path}")
+        except Exception as e:
+            logger.error(f"Error reading .json file for {file_path}: {e}")
 
     try:
+        # If we didn't get SHA256 from the .json file, calculate it
+        if not sha256:
+            sha256 = await calculate_sha256(real_path)
+            
         metadata = LoraMetadata(
             file_name=base_name,
             model_name=base_name,
             file_path=normalize_path(file_path),
             size=os.path.getsize(real_path),
             modified=os.path.getmtime(real_path),
-            sha256=await calculate_sha256(real_path),
+            sha256=sha256,
             base_model="Unknown",  # Will be updated later
             usage_tips="",
             notes="",
@@ -125,7 +142,7 @@ async def load_metadata(file_path: str) -> Optional[LoraMetadata]:
                 if not preview_url or not os.path.exists(preview_url):
                     base_name = os.path.splitext(os.path.basename(file_path))[0]
                     dir_path = os.path.dirname(file_path)
-                    new_preview_url = normalize_path(_find_preview_file(base_name, dir_path))
+                    new_preview_url = normalize_path(find_preview_file(base_name, dir_path))
                     if new_preview_url != preview_url:
                         data['preview_url'] = new_preview_url
                         needs_update = True