smal: add config class

mxsmal/src/mxsmal/bot.py

@@ -3,6 +3,7 @@
 import logging
 
 from .app import SMALApp
+from .config import SMALConfig
 
 logger = logging.getLogger(__name__)
 
@@ -14,9 +15,10 @@ logger = logging.getLogger(__name__)
 class SMALBot(SMALApp):
     """ """
 
-    def __init__(self, sigil):
+    def __init__(self, sigil, config=None):
         super().__init__()
         self._sigil = sigil
+        self._config = config if config is not None else SMALConfig.create_new()
 
     async def sendmessage(self, roomid, text):
         data = {}

mxsmal/src/mxsmal/config.py

@@ -0,0 +1,156 @@
+# Copyright (C) 2026 saces@c-base.org
+# SPDX-License-Identifier: AGPL-3.0-only
+import os
+import pathlib
+import sys
+from dataclasses import asdict, dataclass
+from enum import Enum
+
+import dacite
+
+
+class ConfigError(Exception):
+    pass
+
+
+class ConfigFileType(Enum):
+    YAML = "yaml"
+    TOML = "toml"
+    JSON = "json"
+
+
+@dataclass
+class ConfigFile:
+
+    @classmethod
+    def create_new(cls):
+        return cls()
+
+    @classmethod
+    def load_file(cls, file_path=None, file_type=None, cast=None):
+        """
+        automagic config file loader
+
+        Args:
+            file_path: fd, filename or "-"
+            type: type of config file, required for fd and "-"
+            cast: type hint decite/decoder
+
+        Returns: config object
+
+        """
+        if file_path is None:
+            return cls()
+
+        if file_type is None:
+            # try to guess the type from name extension
+            ext = pathlib.Path(file_path).suffix
+            if ext in [".yaml", ".yml"]:
+                file_type = ConfigFileType.YAML
+            elif ext in [".toml", ".tml"]:
+                file_type = ConfigFileType.TOML
+            elif ext == ".json":
+                file_type = ConfigFileType.JSON
+            else:
+                raise ConfigError("Unable to guess the file type from name.")
+
+        # try to load the data
+        data = None
+        if file_path == "-":
+            file_path = sys.stdin
+        if file_type == ConfigFileType.TOML:
+            import toml
+
+            data = toml.load(file_path)
+        elif file_type == ConfigFileType.YAML:
+            import yaml
+
+            data = yaml.safe_load(file_path)
+        elif file_type == ConfigFileType.JSON:
+            import json
+
+            with open(file_path) as f:
+                data = json.load(f)
+        else:
+            # after adding new file types you may need to update the logic
+            raise RuntimeError()
+
+        return dacite.from_dict(
+            data_class=cls,
+            data=data,
+            # tell dacite to cast some types while deserializing
+            config=dacite.Config(cast=cast) if cast else None,
+        )
+
+    @classmethod
+    def load_file_auto(cls, file_path: str, file_type=None, cast=None):
+        if os.path.exists(file_path):
+            return cls.load_file(file_path, file_type, cast)
+        else:
+            return cls()
+
+    def save_file(self, file_path: str, file_type=None):
+
+        if file_path == "-" and file_type is None:
+            raise ConfigError("file_type required if printing to stdout")
+
+        if file_type is None:
+            # try to guess the type from name extension
+            ext = pathlib.Path(file_path).suffix
+            if ext in [".yaml", ".yml"]:
+                file_type = ConfigFileType.YAML
+            elif ext in [".toml", ".tml"]:
+                file_type = ConfigFileType.TOML
+            elif ext == ".json":
+                file_type = ConfigFileType.JSON
+            else:
+                raise ConfigError("Unable to guess the file type from name.")
+
+        def my_factory(data):
+            def convert_value(obj):
+                if isinstance(obj, Enum):
+                    return obj.value
+                return obj
+
+            return dict((k, convert_value(v)) for k, v in data)
+
+        d = asdict(self, dict_factory=my_factory)
+
+        if file_path == "-":
+            file_path = sys.stdout
+            if file_type == ConfigFileType.TOML:
+                import toml
+
+                toml.dump(d, file_path)
+            elif file_type == ConfigFileType.YAML:
+                import yaml
+
+                yaml.dump(d, file_path)
+            elif file_type == ConfigFileType.JSON:
+                import json
+
+                json.dump(d, file_path)
+            else:
+                # after adding new file types you may need to update the logic
+                raise RuntimeError()
+        else:
+            if file_type == ConfigFileType.TOML:
+                import toml
+
+                with open(file_path, "w") as file:
+                    toml.dump(d, file)
+            elif file_type == ConfigFileType.YAML:
+                import yaml
+
+                with open(file_path, "w") as file:
+                    yaml.dump(d, file)
+            elif file_type == ConfigFileType.JSON:
+                import json
+
+                with open(file_path, "w") as file:
+                    json.dump(d, file)
+
+
+@dataclass
+class SMALConfig(ConfigFile):
+    pass