Reasonable defaults, isolate tests, EOS_LOGGING_LEVEL, EOS_CONFIG_DIR

* Add EOS_CONFIG_DIR to set config dir (relative path to EOS_DIR or
   absolute path).
    - config_folder_path read-only
    - config_file_path read-only
 * Default values to support app start with empty config:
    - latitude/longitude (Berlin)
    - optimization_ev_available_charge_rates_percent (null, so model
      default value is used)
    - Enable Akkudoktor electricity price forecast (docker-compose).
 * Fix some endpoints (empty data, remove unused params, fix types).
 * cacheutil: Use cache dir. Closes #240
 * Support EOS_LOGGING_LEVEL environment variable to set log level.
 * tests: All tests use separate temporary config
    - Add pytest switch --check-config-side-effect to check user
      config file existence after each test. Will also fail if user config
      existed before test execution (but will only check after the test has
      run).
      Enable flag in github workflow.
    - Globally mock platformdirs in config module. Now no longer required
      to patch individually.
      Function calls to config instance (e.g. merge_settings_from_dict)
      were unaffected previously.
 * Set Berlin as default location (default config/docker-compose).

src/akkudoktoreos/config/config.py

@@ -14,7 +14,7 @@ import shutil
 from pathlib import Path
 from typing import Any, ClassVar, List, Optional
 
-import platformdirs
+from platformdirs import user_config_dir, user_data_dir
 from pydantic import Field, ValidationError, computed_field
 
 # settings
@@ -40,6 +40,24 @@ from akkudoktoreos.utils.utils import UtilsCommonSettings
 logger = get_logger(__name__)
 
 
+def get_absolute_path(
+    basepath: Optional[Path | str], subpath: Optional[Path | str]
+) -> Optional[Path]:
+    """Get path based on base path."""
+    if isinstance(basepath, str):
+        basepath = Path(basepath)
+    if subpath is None:
+        return basepath
+
+    if isinstance(subpath, str):
+        subpath = Path(subpath)
+    if subpath.is_absolute():
+        return subpath
+    if basepath is not None:
+        return basepath.joinpath(subpath)
+    return None
+
+
 class ConfigCommonSettings(SettingsBaseModel):
     """Settings for common configuration."""
 
@@ -60,22 +78,14 @@ class ConfigCommonSettings(SettingsBaseModel):
     @property
     def data_output_path(self) -> Optional[Path]:
         """Compute data_output_path based on data_folder_path."""
-        if self.data_output_subpath is None:
-            return self.data_folder_path
-        if self.data_folder_path and self.data_output_subpath:
-            return self.data_folder_path.joinpath(self.data_output_subpath)
-        return None
+        return get_absolute_path(self.data_folder_path, self.data_output_subpath)
 
     # Computed fields
     @computed_field  # type: ignore[prop-decorator]
     @property
     def data_cache_path(self) -> Optional[Path]:
         """Compute data_cache_path based on data_folder_path."""
-        if self.data_cache_subpath is None:
-            return self.data_folder_path
-        if self.data_folder_path and self.data_cache_subpath:
-            return self.data_folder_path.joinpath(self.data_cache_subpath)
-        return None
+        return get_absolute_path(self.data_folder_path, self.data_cache_subpath)
 
 
 class SettingsEOS(
@@ -114,9 +124,10 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
 
     Initialization Process:
       - Upon instantiation, the singleton instance attempts to load a configuration file in this order:
-        1. The directory specified by the `EOS_DIR` environment variable.
-        2. A platform specific default directory for EOS.
-        3. The current working directory.
+        1. The directory specified by the `EOS_CONFIG_DIR` environment variable
+        2. The directory specified by the `EOS_DIR` environment variable.
+        3. A platform specific default directory for EOS.
+        4. The current working directory.
       - The first available configuration file found in these directories is loaded.
       - If no configuration file is found, a default configuration file is created in the platform
         specific default directory, and default settings are loaded into it.
@@ -150,21 +161,29 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
     APP_NAME: ClassVar[str] = "net.akkudoktor.eos"  # reverse order
     APP_AUTHOR: ClassVar[str] = "akkudoktor"
     EOS_DIR: ClassVar[str] = "EOS_DIR"
+    EOS_CONFIG_DIR: ClassVar[str] = "EOS_CONFIG_DIR"
     ENCODING: ClassVar[str] = "UTF-8"
     CONFIG_FILE_NAME: ClassVar[str] = "EOS.config.json"
 
     _settings: ClassVar[Optional[SettingsEOS]] = None
     _file_settings: ClassVar[Optional[SettingsEOS]] = None
 
-    config_folder_path: Optional[Path] = Field(
-        None, description="Path to EOS configuration directory."
-    )
-
-    config_file_path: Optional[Path] = Field(
-        default=None, description="Path to EOS configuration file."
-    )
+    _config_folder_path: Optional[Path] = None
+    _config_file_path: Optional[Path] = None
 
     # Computed fields
+    @computed_field  # type: ignore[prop-decorator]
+    @property
+    def config_folder_path(self) -> Optional[Path]:
+        """Path to EOS configuration directory."""
+        return self._config_folder_path
+
+    @computed_field  # type: ignore[prop-decorator]
+    @property
+    def config_file_path(self) -> Optional[Path]:
+        """Path to EOS configuration file."""
+        return self._config_file_path
+
     @computed_field  # type: ignore[prop-decorator]
     @property
     def config_default_file_path(self) -> Path:
@@ -297,7 +316,7 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
                 pass
         # From platform specific default path
         try:
-            data_dir = platformdirs.user_data_dir(self.APP_NAME, self.APP_AUTHOR)
+            data_dir = Path(user_data_dir(self.APP_NAME, self.APP_AUTHOR))
             if data_dir is not None:
                 data_dir.mkdir(parents=True, exist_ok=True)
                 self.data_folder_path = data_dir
@@ -308,47 +327,27 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
         data_dir = Path.cwd()
         self.data_folder_path = data_dir
 
-    def _config_folder_path(self) -> Optional[Path]:
-        """Finds the first directory containing a valid configuration file.
+    def _get_config_file_path(self) -> tuple[Path, bool]:
+        """Finds the a valid configuration file or returns the desired path for a new config file.
 
         Returns:
-            Path: The path to the configuration directory, or None if not found.
+            tuple[Path, bool]: The path to the configuration directory and if there is already a config file there
         """
         config_dirs = []
-        config_dir = None
-        env_dir = os.getenv(self.EOS_DIR)
-        logger.debug(f"Envionment '{self.EOS_DIR}': '{env_dir}'")
+        env_base_dir = os.getenv(self.EOS_DIR)
+        env_config_dir = os.getenv(self.EOS_CONFIG_DIR)
+        env_dir = get_absolute_path(env_base_dir, env_config_dir)
+        logger.debug(f"Envionment config dir: '{env_dir}'")
         if env_dir is not None:
-            config_dirs.append(Path(env_dir).resolve())
-        config_dirs.append(Path(platformdirs.user_config_dir(self.APP_NAME)))
+            config_dirs.append(env_dir.resolve())
+        config_dirs.append(Path(user_config_dir(self.APP_NAME)))
         config_dirs.append(Path.cwd())
         for cdir in config_dirs:
             cfile = cdir.joinpath(self.CONFIG_FILE_NAME)
             if cfile.exists():
                 logger.debug(f"Found config file: '{cfile}'")
-                config_dir = cdir
-                break
-        return config_dir
-
-    def _config_file_path(self) -> Path:
-        """Finds the path to the configuration file.
-
-        Returns:
-            Path: The path to the configuration file. May not exist.
-        """
-        config_file = None
-        config_dir = self._config_folder_path()
-        if config_dir is None:
-            # There is currently no configuration file - create it in default path
-            env_dir = os.getenv(self.EOS_DIR)
-            if env_dir is not None:
-                config_dir = Path(env_dir).resolve()
-            else:
-                config_dir = Path(platformdirs.user_config_dir(self.APP_NAME))
-            config_file = config_dir.joinpath(self.CONFIG_FILE_NAME)
-        else:
-            config_file = config_dir.joinpath(self.CONFIG_FILE_NAME)
-        return config_file
+                return cfile, True
+        return config_dirs[0].joinpath(self.CONFIG_FILE_NAME), False
 
     def from_config_file(self) -> None:
         """Loads the configuration file settings for EOS.
@@ -356,14 +355,14 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
         Raises:
             ValueError: If the configuration file is invalid or incomplete.
         """
-        config_file = self._config_file_path()
+        config_file, exists = self._get_config_file_path()
         config_dir = config_file.parent
-        if not config_file.exists():
+        if not exists:
             config_dir.mkdir(parents=True, exist_ok=True)
             try:
                 shutil.copy2(self.config_default_file_path, config_file)
             except Exception as exc:
-                logger.warning(f"Could not copy default config: {exc}. Using default copy...")
+                logger.warning(f"Could not copy default config: {exc}. Using default config...")
                 config_file = self.config_default_file_path
                 config_dir = config_file.parent
 
@@ -376,8 +375,8 @@ class ConfigEOS(SingletonMixin, SettingsEOS):
 
         self.update()
         # Everthing worked, remember the values
-        self.config_folder_path = config_dir
-        self.config_file_path = config_file
+        self._config_folder_path = config_dir
+        self._config_file_path = config_file
 
     def to_config_file(self) -> None:
         """Saves the current configuration to the configuration file.