updating and refactoring codebase for improved performance and maintainability

cmdlet/get_tag.py

@@ -14,14 +14,20 @@ import sys
 
 from SYS.logger import log, debug
 
-from plugins.metadata_provider import (
-    get_default_subject_scrape_plugin,
-    get_metadata_plugin,
-    get_metadata_plugin_for_url,
-    list_metadata_plugins,
-    scrape_isbn_metadata,
-    scrape_openlibrary_metadata,
-)
+# plugins.metadata_provider is deferred: it transitively loads yt_dlp, Cryptodome,
+# imdbinfo, musicbrainzngs and ~1400 modules (~1.5s). Import lazily on first use.
+_METADATA_PROVIDER_MOD: Optional[Any] = None
+
+
+def _mp() -> Any:
+    """Return the (lazily imported) plugins.metadata_provider module."""
+    global _METADATA_PROVIDER_MOD
+    if _METADATA_PROVIDER_MOD is None:
+        import plugins.metadata_provider as _m
+        _METADATA_PROVIDER_MOD = _m
+    return _METADATA_PROVIDER_MOD
+
+
 from pathlib import Path
 from typing import Any, Dict, List, Optional, Sequence, Tuple
 
@@ -41,11 +47,6 @@ CmdletArg = sh.CmdletArg
 SharedArgs = sh.SharedArgs
 parse_cmdlet_args = sh.parse_cmdlet_args
 
-try:
-    from SYS.metadata import extract_title
-except ImportError:
-    extract_title = None
-
 
 def _dedup_tags_preserve_order(tags: List[str]) -> List[str]:
     """Deduplicate tags case-insensitively while preserving order."""
@@ -210,7 +211,7 @@ def _extract_tag_value(tags_list: List[str], namespace: str) -> Optional[str]:
 
 def _scrape_openlibrary_metadata(olid: str) -> List[str]:
     try:
-        return list(scrape_openlibrary_metadata(olid))
+        return list(_mp().scrape_openlibrary_metadata(olid))
     except Exception as e:
         log(f"OpenLibrary scraping error: {e}", file=sys.stderr)
         return []
@@ -218,7 +219,7 @@ def _scrape_openlibrary_metadata(olid: str) -> List[str]:
 
 def _scrape_isbn_metadata(isbn: str) -> List[str]:
     try:
-        return list(scrape_isbn_metadata(isbn))
+        return list(_mp().scrape_isbn_metadata(isbn))
     except Exception as e:
         log(f"ISBN scraping error: {e}", file=sys.stderr)
         return []
@@ -400,7 +401,7 @@ def _run_impl(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
         scrape_target = str(scrape_url or "").strip() if scrape_url is not None else ""
         plugin = None
         if scrape_target.startswith(("http://", "https://")):
-            plugin = get_metadata_plugin_for_url(scrape_target, config)
+            plugin = _mp().get_metadata_plugin_for_url(scrape_target, config)
             if plugin is None:
                 log("No metadata plugin can scrape this URL", file=sys.stderr)
                 return 1
@@ -412,9 +413,9 @@ def _run_impl(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
             return 0
 
         if scrape_target:
-            plugin = get_metadata_plugin(scrape_target, config)
+            plugin = _mp().get_metadata_plugin(scrape_target, config)
         else:
-            plugin = get_default_subject_scrape_plugin(config)
+            plugin = _mp().get_default_subject_scrape_plugin(config)
         if plugin is None:
             if scrape_target:
                 log(f"Unknown metadata plugin: {scrape_target}", file=sys.stderr)
@@ -749,7 +750,7 @@ def _run_impl(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
             )
             return 0
 
-        plugin_for_apply = get_metadata_plugin(str(result_provider), config)
+        plugin_for_apply = _mp().get_metadata_plugin(str(result_provider), config)
         if plugin_for_apply is not None:
             apply_tags = plugin_for_apply.filter_tags_for_store_apply(
                 [str(t) for t in result_tags if t is not None]
@@ -944,18 +945,14 @@ def _run_impl(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
     return 0
 
 
-_SCRAPE_CHOICES = []
-try:
-    _SCRAPE_CHOICES = sorted(list_metadata_plugins().keys())
-except Exception:
-    _SCRAPE_CHOICES = [
-        "itunes",
-        "openlibrary",
-        "googlebooks",
-        "google",
-        "musicbrainz",
-        "imdb",
-    ]
+_SCRAPE_CHOICES = [
+    "itunes",
+    "openlibrary",
+    "googlebooks",
+    "google",
+    "musicbrainz",
+    "imdb",
+]
 
 
 class Get_Tag(Cmdlet):