update: make uv run paperlib --help works

paperlib_build_backend.py

@@ -0,0 +1,165 @@
+"""A tiny local build backend for paperlib.
+
+This keeps `uv run paperlib ...` working without requiring network access
+to download a third-party build backend.
+"""
+
+from __future__ import annotations
+
+import base64
+import hashlib
+from pathlib import Path
+from zipfile import ZIP_DEFLATED, ZipFile
+
+PROJECT_ROOT = Path(__file__).resolve().parent
+SRC_ROOT = PROJECT_ROOT / "src"
+PACKAGE_ROOT = SRC_ROOT / "paperlib"
+NAME = "paperlib"
+VERSION = "0.1.0"
+
+
+def _dist_info_dir() -> str:
+  return f"{NAME}-{VERSION}.dist-info"
+
+
+def _wheel_name() -> str:
+  return f"{NAME}-{VERSION}-py3-none-any.whl"
+
+
+def _metadata_contents() -> bytes:
+  return "\n".join(
+    [
+      "Metadata-Version: 2.1",
+      f"Name: {NAME}",
+      f"Version: {VERSION}",
+      "Summary: Local-first CLI toolkit for managing a paper library",
+      "",
+    ]
+  ).encode("utf-8")
+
+
+def _wheel_contents() -> bytes:
+  return "\n".join(
+    [
+      "Wheel-Version: 1.0",
+      "Generator: paperlib_build_backend",
+      "Root-Is-Purelib: true",
+      "Tag: py3-none-any",
+      "",
+    ]
+  ).encode("utf-8")
+
+
+def _entry_points_contents() -> bytes:
+  return b"[console_scripts]\npaperlib = paperlib.cli:main\n"
+
+
+def _hash_bytes(data: bytes) -> tuple[str, str]:
+  digest = hashlib.sha256(data).digest()
+  encoded = base64.urlsafe_b64encode(digest).rstrip(b"=").decode("ascii")
+  return f"sha256={encoded}", str(len(data))
+
+
+def _package_files() -> list[tuple[str, bytes]]:
+  files: list[tuple[str, bytes]] = []
+  for path in sorted(PACKAGE_ROOT.rglob("*")):
+    if path.is_file():
+      relative = path.relative_to(SRC_ROOT).as_posix()
+      files.append((relative, path.read_bytes()))
+  return files
+
+
+def _build_records(files: list[tuple[str, bytes]]) -> bytes:
+  record_path = f"{_dist_info_dir()}/RECORD"
+  rows: list[list[str]] = []
+  for path, data in files:
+    digest, size = _hash_bytes(data)
+    rows.append([path, digest, size])
+  rows.append([record_path, "", ""])
+
+  output: list[str] = []
+  for row in rows:
+    output.append(",".join(row))
+  return ("\n".join(output) + "\n").encode("utf-8")
+
+
+def _build_wheel_archive(target: Path) -> str:
+  files = _package_files()
+  files.extend(
+    [
+      (f"{_dist_info_dir()}/METADATA", _metadata_contents()),
+      (f"{_dist_info_dir()}/WHEEL", _wheel_contents()),
+      (f"{_dist_info_dir()}/entry_points.txt", _entry_points_contents()),
+    ]
+  )
+  files.append((f"{_dist_info_dir()}/RECORD", _build_records(files)))
+
+  wheel_path = target / _wheel_name()
+  with ZipFile(wheel_path, "w", compression=ZIP_DEFLATED) as zf:
+    for archive_path, data in files:
+      zf.writestr(archive_path, data)
+  return wheel_path.name
+
+
+def build_wheel(
+  wheel_directory: str,
+  config_settings: dict[str, object] | None = None,
+  metadata_directory: str | None = None,
+) -> str:
+  """Build a wheel for paperlib."""
+  del config_settings, metadata_directory
+  target = Path(wheel_directory)
+  target.mkdir(parents=True, exist_ok=True)
+  return _build_wheel_archive(target)
+
+
+def build_editable(
+  wheel_directory: str,
+  config_settings: dict[str, object] | None = None,
+  metadata_directory: str | None = None,
+) -> str:
+  """Build an installable wheel for editable requests.
+
+  For now, we return a normal pure-Python wheel; that is sufficient for the
+  project's current bootstrap needs.
+  """
+  return build_wheel(wheel_directory, config_settings, metadata_directory)
+
+
+def get_requires_for_build_wheel(
+  config_settings: dict[str, object] | None = None,
+) -> list[str]:
+  """This backend has no external build requirements."""
+  del config_settings
+  return []
+
+
+def get_requires_for_build_editable(
+  config_settings: dict[str, object] | None = None,
+) -> list[str]:
+  """This backend has no external build requirements."""
+  del config_settings
+  return []
+
+
+def prepare_metadata_for_build_wheel(
+  metadata_directory: str,
+  config_settings: dict[str, object] | None = None,
+) -> str:
+  """Write minimal dist-info metadata for frontends that request it."""
+  del config_settings
+  dist_info = Path(metadata_directory) / _dist_info_dir()
+  dist_info.mkdir(parents=True, exist_ok=True)
+  (dist_info / "METADATA").write_bytes(_metadata_contents())
+  (dist_info / "WHEEL").write_bytes(_wheel_contents())
+  (dist_info / "entry_points.txt").write_bytes(_entry_points_contents())
+  (dist_info / "RECORD").write_text("", encoding="utf-8")
+  return dist_info.name
+
+
+def prepare_metadata_for_build_editable(
+  metadata_directory: str,
+  config_settings: dict[str, object] | None = None,
+) -> str:
+  """Alias editable metadata generation to the wheel metadata implementation."""
+  return prepare_metadata_for_build_wheel(metadata_directory, config_settings)