"""Git source sync for import_docs (phase 28). clone_or_pull(url, dest) clones ``url`` into ``dest`` (shallow, depth 1) the first time, or fast-forwards an existing checkout with ``git pull --ff-only`` on subsequent runs. Auth: nothing special — an ``https://…`` URL uses the OS credential helper / prompts; a ``git@host:repo.git`` URL uses the machine's SSH key. No credentials are stored here; whatever the URL/SSH config supplies is used. This module is the only place the ``git`` CLI is invoked (A11: stdlib ``subprocess`` only, no new packages) — every git command goes through :func:`run_git`: the clone/pull in :func:`clone_or_pull`, the per-file last-commit-date walk in :func:`file_commit_dates` (phase 106), and the docs-push sequence in :mod:`app.core.docs_push` (phase 59). Per-file last-commit dates (phase 106, D2/D10) — behavior verified against scratch repos 2026-09-13: * a LOCAL-PATH checkout made by :func:`clone_or_pull` keeps FULL history (``git clone --depth 1 /local/path`` prints "--depth is ignored in local clones" and does not shallow) → :func:`file_commit_dates` yields TRUE per-file last-commit dates; * a URL-TRANSPORT checkout (https/ssh/``file://``) is shallow, and in a shallow clone git reports the TIP commit as every existing file's last commit (the shallow boundary is each file's history root) → a uniform per-repo tip date: no intra-repo distortion, a real cross-source signal, refreshed on every pull. """ from __future__ import annotations import logging import subprocess from datetime import datetime from pathlib import Path logger = logging.getLogger(__name__) __all__ = ["GitSyncError", "clone_or_pull", "file_commit_dates", "run_git"] class GitSyncError(RuntimeError): """A git clone/pull failed (or git is missing); carries git's stderr.""" def clone_or_pull(url: str, dest: Path | str) -> Path: """Clone ``url`` into ``dest`` (shallow, first run) or fast-forward it. - dest without a ``.git`` (or absent) → ``git clone --depth 1 url dest`` (shallow: the KB is re-imported incrementally anyway). - dest with a ``.git`` → ``git pull --ff-only`` (refuses to merge unrelated histories — a broken checkout fails loudly rather than producing a dirty index). Returns the destination path. Raises :class:`GitSyncError` when git is missing or a git invocation exits non-zero (with git's stderr in the message, so the caller can name the failing repo + reason). """ dest = Path(dest) if not dest.exists() or not (dest / ".git").exists(): dest.parent.mkdir(parents=True, exist_ok=True) run_git(["git", "clone", "--depth", "1", url, str(dest)], cwd=dest.parent) else: run_git(["git", "pull", "--ff-only"], cwd=dest) return dest def _parse_commit_dates(output: str) -> dict[str, datetime]: """Parse ``git log --name-only --format=@@%cI`` output (newest first). A ``@@`` line starts a commit (``%cI`` is ISO-strict, so the date is always aware — parsed with ``datetime.fromisoformat``); the following non-empty, non-``@@`` lines are repo-relative paths. The FIRST sighting of a path wins (the walk is newest-first) — that is the file's last-commit date. Paths are split on whitespace (like name-only output), ``\\``-normalized to ``/``, and a leading ``/`` is stripped. Raises ``ValueError`` on a malformed commit date or a path line before any commit header (the caller fails soft). """ dates: dict[str, datetime] = {} commit: datetime | None = None for line in output.splitlines(): line = line.strip() if not line: continue if line.startswith("@@"): commit = datetime.fromisoformat(line[2:]) continue if commit is None: raise ValueError(f"path line before any commit header: {line!r}") for raw_path in line.split(): path = raw_path.replace("\\", "/").lstrip("/") if path: dates.setdefault(path, commit) return dates def file_commit_dates(dest: Path | str) -> dict[str, datetime]: """Per-file last-commit dates for one checkout (phase 106, D2). ONE ``git log --name-only --format=@@%cI`` walk through :func:`run_git` (the A11 single-invocation site, one git call per source per sync) → ``{repo-relative POSIX path: last-commit datetime}``, newest-first so the first sighting of a path wins. The checkout behavior is pinned (verified 2026-09-13 — see the module docstring): a local-path ``clone_or_pull`` checkout keeps FULL history → TRUE per-file dates; a URL-transport checkout is shallow → the repo's TIP-commit date for every working-tree file (D10: uniform within the repo, real across sources). Fail-soft (pinned): a missing/non-directory checkout, a git failure (:class:`GitSyncError`), or ANY parse anomaly logs a warning and returns ``{}`` — the importer falls back to file mtimes; a date walk must never break a sync. """ dest = Path(dest) if not dest.is_dir(): logger.warning( "file_commit_dates: %s is not a directory — no git dates " "(the importer will fall back to file mtimes)", dest, ) return {} try: output = run_git(["git", "log", "--name-only", "--format=@@%cI"], cwd=dest) except GitSyncError as exc: logger.warning( "file_commit_dates: git log failed for %s: %s — the importer " "will fall back to file mtimes", dest, exc, ) return {} try: return _parse_commit_dates(output) except ValueError as exc: logger.warning( "file_commit_dates: unparseable git log output for %s (%s) — the " "importer will fall back to file mtimes", dest, exc, ) return {} def run_git(argv: list[str], cwd: Path) -> str: """Run one git command, capturing output; raise GitSyncError on failure. The single ``git`` invocation point for the whole app (A11). Every step of :func:`clone_or_pull` and of the docs-push sequence (:mod:`app.core.docs_push`, phase 59) goes through here, so error handling stays uniform: captured stdout on success, and :class:`GitSyncError` carrying git's stderr on a non-zero exit (or when the git binary is missing from PATH). """ try: proc = subprocess.run(argv, cwd=cwd, capture_output=True, text=True) except FileNotFoundError: raise GitSyncError("git was not found on PATH — install git and retry") from None if proc.returncode != 0: raise GitSyncError( f"git {' '.join(argv[1:])} failed (exit {proc.returncode}): " f"{proc.stderr.strip()}" ) return proc.stdout