Add filesystem scanner

groove/db/manager.py

@@ -40,4 +40,4 @@ class DatabaseManager:
             self.session.close()
 
 
-database_manager = DatabaseManager()
+database_manager = DatabaseManager

groove/db/scanner.py

@@ -0,0 +1,62 @@
+import logging
+import os
+import sys
+
+from pathlib import Path
+from typing import Callable, Union, Iterable
+from sqlalchemy import func
+
+import groove.db
+
+
+class MediaScanner:
+    """
+    Scan a directory structure containing audio files and import them into the database.
+    """
+    def __init__(self, root: Path, db: Callable, glob: Union[str, None] = None) -> None:
+        self._db = db
+        self._glob = tuple((glob or os.environ.get('MEDIA_GLOB')).split(','))
+        try:
+            self._root = root or Path(os.environ.get('MEDIA_ROOT'))
+        except TypeError:
+            logging.error("Could not find media root. Do you need to define MEDIA_ROOT in your environment?")
+            sys.exit(1)
+        logging.debug(f"Configured media scanner for root: {self._root}")
+
+    @property
+    def db(self) -> Callable:
+        return self._db
+
+    @property
+    def root(self) -> Path:
+        return self._root
+
+    @property
+    def glob(self) -> tuple:
+        return self._glob
+
+    def find_sources(self, pattern):
+        return self.root.rglob(pattern)  # pragma: no-cover
+
+    def import_tracks(self, sources: Iterable) -> None:
+        for path in sources:
+            relpath = str(path.relative_to(self.root))
+            stmt = groove.db.track.insert({'relpath': relpath}).prefix_with('OR IGNORE')
+            self.db.execute(stmt)
+        self.db.commit()
+
+    def scan(self) -> int:
+        """
+        Walk the media root and insert Track table entries for each media file
+        found. Existing entries will be ignored.
+        """
+        count = self.db.query(func.count(groove.db.track.c.relpath)).scalar()
+        logging.debug(f"Track table currently contains {count} entries.")
+        for pattern in self.glob:
+            self.import_tracks(self.find_sources(pattern))
+            newcount = self.db.query(func.count(groove.db.track.c.relpath)).scalar() - count
+            logging.debug(f"Inserted {newcount} new tracks so far this run...")
+        return newcount
+
+
+media_scanner = MediaScanner