refactor: cleanup scripts

scripts/list-hosts.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+"""
+Print the nixosConfigurations defined in flake.nix.
+
+Parses flake.nix directly (no `nix eval`, so it works without nix tooling
+and is fast).  Brace-matches to find the closing `}` of nixosConfigurations
+so it handles nested attrsets correctly.
+"""
+
+import re
+import sys
+from pathlib import Path
+
+
+def list_hosts(flake_path: Path) -> list[str]:
+    src = flake_path.read_text()
+    m = re.search(r"nixosConfigurations\s*=\s*\{", src)
+    if not m:
+        return []
+
+    # Brace-match to find the matching closing }.
+    depth, i, close = 0, m.end() - 1, None
+    while i < len(src):
+        c = src[i]
+        if c == "{":
+            depth += 1
+        elif c == "}":
+            depth -= 1
+            if depth == 0:
+                close = i
+                break
+        i += 1
+
+    block = src[m.end():close] if close is not None else ""
+    return re.findall(
+        r"^[ \t]*([A-Za-z_][\w-]*)\s*=\s*nixpkgs\.lib\.nixosSystem",
+        block,
+        re.M,
+    )
+
+
+def main() -> int:
+    flake = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("flake.nix")
+    if not flake.is_file():
+        print(f"[-] not a file: {flake}", file=sys.stderr)
+        return 1
+    for name in list_hosts(flake):
+        print(name)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())