write logs to XDG_STATE_HOME

rose/__init__.py

@@ -1,9 +1,15 @@
 import logging
+import os
 import sys
+from pathlib import Path
 
 logger = logging.getLogger()
 logger.setLevel(logging.INFO)
 
+STATE_HOME = Path(os.environ.get("XDG_STATE_HOME", "~/.local/state")).expanduser() / "rose"
+STATE_HOME.mkdir(parents=True, exist_ok=True)
+LOGFILE = STATE_HOME / "rose.log"
+
 # Add a logging handler for stdout unless we are testing. Pytest
 # captures logging output on its own.
 if "pytest" not in sys.modules:  # pragma: no cover
@@ -14,3 +20,11 @@
     stream_handler = logging.StreamHandler(sys.stdout)
     stream_handler.setFormatter(stream_formatter)
     logger.addHandler(stream_handler)
+
+    file_formatter = logging.Formatter(
+        "[%(asctime)s] [%(name)s:%(lineno)s] %(levelname)s: %(message)s",
+        datefmt="%H:%M:%S",
+    )
+    file_handler = logging.FileHandler(LOGFILE)
+    file_handler.setFormatter(file_formatter)
+    logger.addHandler(file_handler)