Add log level config option

* Log levels can now be set via the command line and the configuration
  file.
* ServerConfig.load() function takes a file-like object now, rather than
  a string

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

omnibot/config.py

@@ -1,6 +1,6 @@
 import dataclasses
 from pathlib import Path
-from typing import Any, Mapping, Sequence, Set
+from typing import IO, Any, Mapping, Sequence, Set
 
 import toml
 
@@ -31,12 +31,10 @@ class ServerConfig:
     plugins: Sequence[PluginConfig] = dataclasses.field(default_factory=list)
     channels: Sequence[str] = dataclasses.field(default_factory=list)
     nick: str = "omnibot"
+    loglevel: str | None = None
 
-    def load(self, path: Path | str):
-        if isinstance(path, str):
-            path = Path(path)
-        with open(path) as fp:
-            obj = toml.load(fp)
+    def load(self, fp: IO[str]):
+        obj = toml.load(fp)
 
         if "server" not in obj:
             raise ConfigError("server", "must be present")
@@ -81,6 +79,14 @@ class ServerConfig:
                 raise ConfigError("nick", "must be a string")
             self.nick = obj["nick"]
 
+        if "loglevel" in obj:
+            if not isinstance(obj["loglevel"], str):
+                raise ConfigError("loglevel", "must be a string")
+            loglevels = ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
+            if obj["loglevel"] not in loglevels:
+                raise ConfigError("loglevel", "must be one of: " + " ".join(loglevels))
+            self.loglevel = obj["loglevel"]
+
     @property
     def all_channels(self) -> Set[str]:
         channels = set(self.channels)