Initial commit with functional framework(!) and example plugin

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

omnibot/config.py

@@ -0,0 +1,85 @@
+import dataclasses
+from pathlib import Path
+from typing import Any, Mapping, Sequence, Set
+
+import toml
+
+
+PluginConfig = Mapping[str, Any]
+
+
+class ConfigError(Exception):
+    def __init__(self, which: str, hint: str | None, plugin: str | None = None):
+        self.which = which
+        self.hint = hint
+        self.plugin = plugin
+        msg = f"{self.which}"
+        if self.hint:
+            msg = f"{msg}: {self.hint}"
+        if self.plugin:
+            msg = f"in config for plugin {plugin}: {msg}"
+        else:
+            msg = f"in server config: {msg}"
+        super(ConfigError, self).__init__(msg)
+
+
+@dataclasses.dataclass
+class ServerConfig:
+    server: str = ""
+    use_ssl: bool = False
+    port: int = 6667
+    plugins: Sequence[PluginConfig] = dataclasses.field(default_factory=list)
+    channels: Sequence[str] = dataclasses.field(default_factory=list)
+    nick: str = "omnibot"
+
+    def load(self, path: Path | str):
+        if isinstance(path, str):
+            path = Path(path)
+        with open(path) as fp:
+            obj = toml.load(fp)
+
+        if "server" not in obj:
+            raise ConfigError("server", "must be present")
+        if not isinstance(obj["server"], str):
+            raise ConfigError("server", "must be a string")
+        self.server = obj["server"]
+
+        if "use_ssl" in obj:
+            if not isinstance(obj["use_ssl"], bool):
+                raise ConfigError("use_ssl", "must be a boolean")
+            self.use_ssl = obj["use_ssl"]
+        else:
+            # Don't use SSL by default
+            self.use_ssl = False
+
+        if "port" in obj:
+            if not isinstance(obj["port"], int):
+                raise ConfigError("port", "must be an integer")
+            if not (0 < obj["port"] <= 65535):
+                raise ConfigError("port", "must be between 0 and 65535")
+            self.port = obj["port"]
+        else:
+            if self.use_ssl:
+                self.port = 6697
+            else:
+                self.port = 6667
+
+        if "plugins" in obj:
+            if not isinstance(obj["plugins"], Sequence):
+                raise ConfigError(
+                    "plugins", "must be a mapping of configuration values"
+                )
+            self.plugins = obj["plugins"]
+
+        if "nick" in obj:
+            if not isinstance(obj["nick"], str):
+                raise ConfigError("nick", "must be a string")
+            self.nick = obj["nick"]
+
+    @property
+    def all_channels(self) -> Set[str]:
+        channels = set(self.channels)
+        for plugin in self.plugins:
+            if "channels" in plugin:
+                channels |= set(plugin["channels"])
+        return channels