Json configuration (#141)

* Add json config
* Adjust code to new config

---------

Co-authored-by: Chris <git@nootch.de>

tests/test_config.py

@@ -0,0 +1,71 @@
+import json
+from pathlib import Path
+
+import pytest
+from pydantic import ValidationError
+
+from akkudoktoreos.config import (
+    CONFIG_FILE_NAME,
+    DEFAULT_CONFIG_FILE,
+    get_config_file,
+    load_config,
+)
+
+
+def test_config() -> None:
+    """Test the default config file."""
+    try:
+        load_config(Path.cwd())
+    except ValidationError as exc:
+        pytest.fail(f"Default configuration is not valid: {exc}")
+
+
+def test_config_copy(tmp_path: Path) -> None:
+    """Test if the config is copied to the provided path."""
+    assert DEFAULT_CONFIG_FILE == get_config_file(Path("does", "not", "exist"), False)
+
+    load_config(tmp_path, True)
+    expected_config = tmp_path.joinpath(CONFIG_FILE_NAME)
+
+    assert expected_config == get_config_file(tmp_path, False)
+    assert expected_config.is_file()
+
+
+def test_config_merge(tmp_path: Path) -> None:
+    """Test if config is merged and updated correctly."""
+    config_file = tmp_path.joinpath(CONFIG_FILE_NAME)
+    custom_config = {
+        "eos": {
+            "optimization_hours": 30,
+            "penalty": 21,
+            "does_not_exist": "nope",
+            "available_charging_rates_in_percentage": "False entry",
+        }
+    }
+    with config_file.open("w") as f_out:
+        json.dump(custom_config, f_out)
+
+    assert config_file.exists()
+
+    with pytest.raises(ValueError):
+        # custom configuration is broken but not updated.
+        load_config(tmp_path, tmp_path, False)
+
+    with config_file.open("r") as f_in:
+        # custom configuration is not changed.
+        assert json.load(f_in) == custom_config
+
+    config = load_config(tmp_path)
+
+    assert config.eos.optimization_hours == 30
+    assert config.eos.penalty == 21
+
+
+def test_setup(tmp_path: Path) -> None:
+    """Test setup."""
+    config = load_config(tmp_path, True)
+    config.run_setup()
+
+    assert tmp_path.joinpath(CONFIG_FILE_NAME).is_file()
+    assert tmp_path.joinpath(config.directories.cache).is_dir()
+    assert tmp_path.joinpath(config.directories.output).is_dir()