Feature/Improve Configuration options and handling (#385)

* Refactor configuration management: remove dataclass-based schema and simplify CONFIG structure.

* Refactor configuration loading: switch from `os` to `pathlib`, streamline YAML loading logic.

* Refactor logging setup: split handler creation into dedicated functions, simplify configuration logic.

* Improve logging configurability and safety

- Add support for `RotatingFileHandler` to prevent large log files.
- Introduce `console` flag for optional console logging.
- Default to `NullHandler` when no handlers are configured for better library behavior.

* Temp

* Temp

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* Refactor configuration and logging: remove unused `merge_configs` function, streamline logging setup, and encapsulate `_setup_logging` as an internal function.

* Remove unused `change_logging_level` import and export.

* Add tests for config.py

* Expand `config.py` test coverage: add tests for custom config loading, logging setup, dict roundtrip, and attribute modification.

* Expand `test_config.py` coverage: add modeling config persistence test, refine logging reset, and improve partial config load assertions.

* Expand `test_config.py` coverage: add teardown for state cleanup and reset modeling config in setup.

* Add `CONFIG.reset()` method and expand test coverage to verify default restoration

* Refactor `CONFIG` to centralize defaults in `_DEFAULTS` and ensure `reset()` aligns with them; add test to verify consistency.

* Refactor `_DEFAULTS` to use `MappingProxyType` for immutability, restructure config hierarchy, and simplify `reset()` implementation for maintainability; update tests accordingly.

* Mark `TestConfigModule` tests to run in a single worker with `@pytest.mark.xdist_group` to prevent global config interference.

* Add default log file

* Update CHANGELOG.md

* Readd change_logging_level() for backwards compatability

* Add more options to config.py

* Add a docstring to config.y

* Add a docstring to config.y

* rename parameter message_format

* Improve color config

* Improve color config

* Update CHANGELOG.md

* Improve color handling

* Improve color handling

* Remove console Logging explicityl from examples

* Make log to console the default

* Make log to console the default

* Add individual level parameters for console and file

* Add extra Handler section

* Use dedicated levels for both handlers

* Switch back to not use Handlers

* Revert "Switch back to not use Handlers"

This reverts commit 05bbccb.

* Revert "Use dedicated levels for both handlers"

This reverts commit ed0542b.

* Revert "Add extra Handler section"

This reverts commit a133cc8.

* Revert "Add individual level parameters for console and file"

This reverts commit 19f81c9.

* Fix CHANGELOG.md

Author: FBumann

CHANGELOG.md

@@ -42,15 +42,23 @@ Please keep the format of the changelog consistent with the other releases, so t
 ## [Unreleased] - ????-??-??
 
 ### ✨ Added
+- Added `CONFIG.reset()` method to restore configuration to default values
+- Added configurable log file rotation settings: `CONFIG.Logging.max_file_size` and `CONFIG.Logging.backup_count`
+- Added configurable log format settings: `CONFIG.Logging.date_format` and `CONFIG.Logging.format`
+- Added configurable console settings: `CONFIG.Logging.console_width` and `CONFIG.Logging.show_path`
+- Added `CONFIG.Logging.Colors` nested class for customizable log level colors using ANSI escape codes (works with both standard and Rich handlers)
 
 ### 💥 Breaking Changes
 
 ### ♻️ Changed
-- Using `h5netcdf` instead of `netCDF4` for dataset I/O operations. This follows the update in `xarray==2025.09.01`
+- Logging and Configuration management changed
 
 ### 🗑️ Deprecated
+- `change_logging_level()` function is now deprecated in favor of `CONFIG.Logging.level` and `CONFIG.apply()`. Will be removed in version 3.0.0.
 
 ### 🔥 Removed
+- Removed unused `config.merge_configs` function from configuration module
+
 
 ### 🐛 Fixed
 
@@ -61,6 +69,8 @@ Please keep the format of the changelog consistent with the other releases, so t
 ### 📝 Docs
 
 ### 👷 Development
+- Greatly expanded test coverage for `config.py` module
+- Added `@pytest.mark.xdist_group` to `TestConfigModule` tests to prevent global config interference
 
 ### 🚧 Known Issues
 
@@ -78,6 +88,7 @@ Until here -->
 
 ### 📦 Dependencies
 - Updated `renovate.config` to treat CalVer packages (xarray and dask) with more care
+- Updated packaging configuration
 
 ---
 

flixopt/__init__.py

@@ -35,5 +35,3 @@
     results,
     solvers,
 )
-
-CONFIG.load_config()

flixopt/calculation.py

@@ -91,13 +91,13 @@ def main_results(self) -> dict[str, Scalar | dict]:
                     model.label_of_element: float(model.size.solution)
                     for component in self.flow_system.components.values()
                     for model in component.model.all_sub_models
-                    if isinstance(model, InvestmentModel) and float(model.size.solution) >= CONFIG.modeling.EPSILON
+                    if isinstance(model, InvestmentModel) and float(model.size.solution) >= CONFIG.Modeling.epsilon
                 },
                 'Not invested': {
                     model.label_of_element: float(model.size.solution)
                     for component in self.flow_system.components.values()
                     for model in component.model.all_sub_models
-                    if isinstance(model, InvestmentModel) and float(model.size.solution) < CONFIG.modeling.EPSILON
+                    if isinstance(model, InvestmentModel) and float(model.size.solution) < CONFIG.Modeling.epsilon
                 },
             },
             'Buses with excess': [