Improved logging mechanism (and a few minor goodies) (#54)

* Improved logging mechanism

* Allow for suppression of any errors regarding failed device updates

logger.py

@@ -1,6 +1,50 @@
 import logging
+import logging.config
+import yaml
 
-import sys
+APP_ROOT = 'bt-mqtt-gw'
+SUPPRESSION_ENABLED = False
 
-_LOGGER = logging.getLogger('bt-mqtt-gw')
-_LOGGER.addHandler(logging.StreamHandler(sys.stdout))
+
+def setup():
+  with open('logger.yaml', 'rt') as f:
+    config = yaml.safe_load(f.read())
+    logging.config.dictConfig(config)
+
+
+def get(name=None):
+  if name:
+    logger_name = '{}.{}'.format(APP_ROOT, name)
+  else:
+    logger_name = APP_ROOT
+  return logging.getLogger(logger_name)
+
+
+def enable_debug_formatter():
+  logging.getLogger().handlers[0].setFormatter(logging.getLogger('dummy_debug').handlers[0].formatter)
+
+
+def reset():
+  app_level = get().getEffectiveLevel()
+
+  root = logging.getLogger()
+  map(root.removeHandler, root.handlers[:])
+  map(root.removeFilter, root.filters[:])
+
+  setup()
+  get().setLevel(app_level)
+  if app_level <= logging.DEBUG:
+    enable_debug_formatter()
+
+
+def suppress_update_failures(suppress):
+  global SUPPRESSION_ENABLED
+  SUPPRESSION_ENABLED = suppress
+
+
+def log_exception(logger, message, *args, **kwargs):
+  if not ('suppress' in kwargs and kwargs.pop('suppress') and SUPPRESSION_ENABLED):
+    if logger.isEnabledFor(logging.DEBUG):
+      logger.exception(message, *args, **kwargs)
+    elif logger.isEnabledFor(logging.WARNING):
+      logger.warning(message, *args, **kwargs)