Establish Railiance Fabric graph model

railiance_fabric/loader.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any
+
+import yaml
+
+from .model import Declaration
+
+DECLARATION_DIRS = ("services", "capabilities", "interfaces", "dependencies", "bindings")
+
+
+def repo_root() -> Path:
+    return Path(__file__).resolve().parents[1]
+
+
+def declaration_files(path: Path) -> list[Path]:
+    path = path.resolve()
+    if path.is_file():
+        return [path]
+
+    fabric = path if path.name == "fabric" else path / "fabric"
+    files: list[Path] = []
+    for directory in DECLARATION_DIRS:
+        root = fabric / directory
+        if root.is_dir():
+            files.extend(sorted(root.glob("*.yaml")))
+            files.extend(sorted(root.glob("*.yml")))
+    return files
+
+
+def load_yaml(path: Path) -> Any:
+    return yaml.safe_load(path.read_text(encoding="utf-8"))
+
+
+def load_declarations(paths: list[Path]) -> tuple[list[Declaration], list[tuple[Path, str]]]:
+    declarations: list[Declaration] = []
+    errors: list[tuple[Path, str]] = []
+    seen_files: set[Path] = set()
+
+    for raw in paths:
+        for path in declaration_files(raw):
+            if path in seen_files:
+                continue
+            seen_files.add(path)
+            try:
+                data = load_yaml(path)
+            except Exception as exc:
+                errors.append((path, str(exc)))
+                continue
+            if not isinstance(data, dict):
+                errors.append((path, "declaration must be a YAML mapping"))
+                continue
+            declarations.append(Declaration(path=path, data=data))
+
+    return declarations, errors