| """TOML configuration loader with environment-variable override support.""" |
|
|
| import os |
| from pathlib import Path |
| from typing import Any |
|
|
| import tomllib |
|
|
|
|
| def _flatten(mapping: dict[str, Any], prefix: str = "") -> dict[str, Any]: |
| """Flatten a nested dict into dotted keys.""" |
| out: dict[str, Any] = {} |
| for k, v in mapping.items(): |
| full = f"{prefix}.{k}" if prefix else k |
| if isinstance(v, dict): |
| out.update(_flatten(v, full)) |
| else: |
| out[full] = v |
| return out |
|
|
|
|
| def _deep_merge(base: dict[str, Any], override: dict[str, Any]) -> dict[str, Any]: |
| """Recursively merge *override* into *base* (non-destructive).""" |
| result = dict(base) |
| for k, v in override.items(): |
| if k in result and isinstance(result[k], dict) and isinstance(v, dict): |
| result[k] = _deep_merge(result[k], v) |
| else: |
| result[k] = v |
| return result |
|
|
|
|
| def load_toml(path: Path) -> dict[str, Any]: |
| """Load a TOML file and return the raw nested dict.""" |
| if not path.exists(): |
| return {} |
| with open(path, "rb") as fh: |
| return tomllib.load(fh) |
|
|
|
|
| def load_config( |
| defaults_path: Path, |
| user_path: Path | None = None, |
| env_prefix: str = "GROK_", |
| ) -> dict[str, Any]: |
| """Load configuration: defaults → user file → environment overrides. |
| |
| Environment variables use the format ``GROK_SECTION_KEY=value``, |
| which maps to the dotted key ``section.key``. |
| """ |
| data = load_toml(defaults_path) |
| if user_path and user_path.exists(): |
| user = load_toml(user_path) |
| data = _deep_merge(data, user) |
|
|
| |
| prefix_len = len(env_prefix) |
| for env_key, env_val in os.environ.items(): |
| if not env_key.startswith(env_prefix): |
| continue |
| parts = env_key[prefix_len:].lower().split("_", 1) |
| if len(parts) == 2: |
| section, key = parts |
| data.setdefault(section, {})[key] = env_val |
|
|
| return data |
|
|
|
|
| def get_nested(data: dict[str, Any], dotted_key: str, default: Any = None) -> Any: |
| """Retrieve a value from a nested dict using a dotted key path.""" |
| keys = dotted_key.split(".") |
| node: Any = data |
| for k in keys: |
| if not isinstance(node, dict): |
| return default |
| node = node.get(k) |
| if node is None: |
| return default |
| return node |
|
|
