feat: add preset resolver

project_manager/preset/resolve.py

@@ -0,0 +1,41 @@
+__all__ = ("PresetResolver",)
+
+
+from pathlib import Path
+from typing import Dict, Iterable
+
+import tomli
+
+from ..util import merge_dicts
+from .model import Preset
+
+
+class PresetResolver:
+    _source_cache: Dict[Path, dict] = {}
+
+    def __init__(self, basepath: Path):
+        self._basepath = basepath
+
+    def iter_sources(self) -> Iterable[Path]:
+        for filepath in (Path(__file__).parent / "default").iterdir():
+            yield filepath
+        user_preset = Path.home() / ".preset.toml"
+        if user_preset.exists():
+            yield user_preset
+        projectpath = self._basepath
+        while projectpath.exists():
+            project_preset = projectpath / ".preset.toml"
+            if project_preset.exists():
+                yield project_preset
+            if projectpath.parent == projectpath:
+                break
+            projectpath = projectpath.parent
+
+    def resolve_preset(self) -> Preset:
+        result_preset_data = {}
+        for filepath in self.iter_sources():
+            if filepath not in self._source_cache:
+                with open(filepath, "rb") as fd:
+                    self._source_cache[filepath] = tomli.load(fd)
+            merge_dicts(result_preset_data, self._source_cache[filepath])
+        return Preset(**result_preset_data)