"""Integration: phase 106 task 03 — ``file_commit_dates`` against real
git scratch repos (D2; phase 107 D11 supersedes phase 106 D10).

Builds scratch repositories with controlled ``GIT_COMMITTER_DATE``s
(the 2026-09-13 verification recipe: file ``a.md`` committed once in
2020, file ``b.md`` committed in 2020 and touched again in 2024, a
``docs/deep.md`` subdirectory file committed once in 2020) and pins
the VERIFIED checkout behavior (phase 107):

* a LOCAL-PATH ``clone_or_pull`` checkout is FULL history → TRUE
  per-file last-commit dates (first-sighting wins: ``a.md`` 2020,
  ``b.md`` 2024, ``docs/deep.md`` 2020);
* a URL-TRANSPORT (``file://``) ``clone_or_pull`` checkout is FULL
  history TOO (D11: no ``--depth`` on the clone) → the SAME true
  per-file dates — the regression pin for the 2026-09-16 bug
  (pre-fix, D10's shallow ``--depth 1`` clone returned the TIP date
  for EVERY file, uniform per repo);
* an EXISTING shallow checkout (made ``--depth 1`` directly by the
  test harness — simulating every pre-phase-107 deployed checkout)
  self-heals on the next ``clone_or_pull``: the
  ``--is-shallow-repository`` probe finds it shallow → ``git fetch
  --unshallow`` → ``git pull --ff-only`` → no longer shallow, true
  per-file dates;
* fail-soft: a directory without ``.git``, an empty repo (no
  commits), a git failure, and a malformed log output all yield
  ``{}`` — a date walk must never break a sync (the importer, task
  04, falls back to file mtimes).

DB-free by design: ``file_commit_dates`` takes a path, no session.
Skipped (not failed) on a machine without the git CLI (the
``test_doc_drafts_api.py`` guard).
"""
from __future__ import annotations

import os
import subprocess
from datetime import UTC, datetime
from pathlib import Path

import pytest

from scripts.git_sync import (
    GitSyncError,
    _parse_commit_dates,  # pyright: ignore[reportPrivateUsage]
    clone_or_pull,
    file_commit_dates,
    run_git,
)


def _git_available() -> bool:
    try:
        proc = subprocess.run(["git", "--version"], capture_output=True, check=False)
        return proc.returncode == 0
    except (FileNotFoundError, OSError):
        return False


#: Real ``git`` in the test environment — skipped cleanly without it
#: (the ``test_doc_drafts_api.py`` house pattern).
GIT = _git_available()

pytestmark = pytest.mark.skipif(not GIT, reason="git CLI not available")

#: The two controlled commit dates (the 2026-09-13 verification recipe).
DATE_A = datetime(2020, 1, 2, 3, 4, 6, tzinfo=UTC)  # commit one (2020)
DATE_B = datetime(2024, 6, 15, 10, 0, 0, tzinfo=UTC)  # commit two = the tip (2024)


def _git(cwd: Path, *argv: str, when: datetime | None = None) -> None:
    """Run one git command for the test harness (fixture setup); a
    non-zero exit fails the fixture, not the test under test."""
    env = os.environ.copy()
    if when is not None:
        iso = when.isoformat()
        env["GIT_AUTHOR_DATE"] = iso
        env["GIT_COMMITTER_DATE"] = iso
    env["GIT_AUTHOR_NAME"] = "T"
    env["GIT_AUTHOR_EMAIL"] = "t@example.com"
    env["GIT_COMMITTER_NAME"] = "T"
    env["GIT_COMMITTER_EMAIL"] = "t@example.com"
    proc = subprocess.run(
        ["git", *argv], cwd=cwd, env=env, capture_output=True, text=True, check=False
    )
    assert proc.returncode == 0, f"git {' '.join(argv)} failed: {proc.stderr}"


@pytest.fixture()
def scratch_repo(tmp_path: Path) -> Path:
    """The 2026-09-13 recipe: commit one (2020-01-02) adds ``a.md``,
    ``b.md``, ``docs/deep.md``; commit two (2024-06-15, the tip)
    touches ONLY ``b.md``."""
    repo = tmp_path / "repo"
    repo.mkdir()
    _git(repo, "init", "-q")
    _git(repo, "config", "user.email", "t@example.com")
    _git(repo, "config", "user.name", "T")
    _git(repo, "config", "commit.gpgsign", "false")
    (repo / "docs").mkdir()
    (repo / "a.md").write_text("# A\nstable since 2020\n", encoding="utf-8")
    (repo / "b.md").write_text("# B\nfirst version\n", encoding="utf-8")
    (repo / "docs" / "deep.md").write_text("# Deep\nalso 2020\n", encoding="utf-8")
    _git(repo, "add", "-A", when=DATE_A)
    _git(repo, "commit", "-qm", "one", when=DATE_A)
    (repo / "b.md").write_text("# B\nupdated 2024\n", encoding="utf-8")
    _git(repo, "add", "-A", when=DATE_B)
    _git(repo, "commit", "-qm", "two", when=DATE_B)
    return repo


def test_local_clone_yields_true_per_file_dates(scratch_repo: Path, tmp_path: Path) -> None:
    """(a) LOCAL-PATH ``clone_or_pull`` → full history (no ``--depth``
    at all, phase 107 D11) → TRUE per-file last-commit dates: the
    first (newest) sighting of each path wins — ``b.md`` the 2024
    touch, the rest the 2020 commit."""
    dest = tmp_path / "local"
    clone_or_pull(str(scratch_repo), dest)
    assert (dest / ".git").exists()  # a real checkout
    assert file_commit_dates(dest) == {
        "a.md": DATE_A,
        "b.md": DATE_B,  # touched again by the tip commit
        "docs/deep.md": DATE_A,
    }


def test_url_clone_yields_true_per_file_dates(scratch_repo: Path, tmp_path: Path) -> None:
    """(b) URL-TRANSPORT ``clone_or_pull`` (``file://`` through the REAL
    function — the 2026-09-16 regression pin): the checkout is FULL
    history (no ``--depth`` — phase 107 D11 supersedes phase 106 D10)
    → NOT shallow, and TRUE per-file last-commit dates: the 2020 files
    stay 2020 and ``b.md`` (touched again at the tip) gets the 2024
    tip date. PRE-FIX this returned DATE_B (the uniform tip date) for
    all three files — the exact bug the owner reported.
    """
    dest = tmp_path / "url-clone"
    clone_or_pull(f"file://{scratch_repo}", dest)
    assert (dest / ".git").exists()  # a real checkout
    assert (
        run_git(["git", "rev-parse", "--is-shallow-repository"], cwd=dest).strip()
        == "false"
    )  # a full-history checkout, not shallow
    assert file_commit_dates(dest) == {
        "a.md": DATE_A,
        "b.md": DATE_B,  # touched again by the tip commit
        "docs/deep.md": DATE_A,
    }


def test_existing_shallow_checkout_self_heals(scratch_repo: Path, tmp_path: Path) -> None:
    """(c) an EXISTING shallow checkout — built ``--depth 1`` directly
    by the harness, simulating every pre-phase-107 deployed checkout
    (live + dev homelab included) — self-heals on the next
    ``clone_or_pull`` (D11): the ``--is-shallow-repository`` probe
    finds it shallow → the ONE-TIME ``git fetch --unshallow`` restores
    the full history (no re-clone) → the usual ``--ff-only`` pull. Pre-
    heal: shallow + the uniform tip date for all files; post-heal:
    full history + true per-file dates."""
    dest = tmp_path / "shallow"
    _git(tmp_path, "clone", "-q", "--depth", "1", f"file://{scratch_repo}", str(dest))
    # Pre-heal: the deployed state the fix must cure.
    assert (
        run_git(["git", "rev-parse", "--is-shallow-repository"], cwd=dest).strip()
        == "true"
    )
    assert file_commit_dates(dest) == {
        "a.md": DATE_B,
        "b.md": DATE_B,
        "docs/deep.md": DATE_B,
    }
    clone_or_pull(f"file://{scratch_repo}", dest)
    # Post-heal: full history and true per-file dates, same as (b).
    assert (
        run_git(["git", "rev-parse", "--is-shallow-repository"], cwd=dest).strip()
        == "false"
    )
    assert file_commit_dates(dest) == {
        "a.md": DATE_A,
        "b.md": DATE_B,
        "docs/deep.md": DATE_A,
    }


def test_directory_without_dotgit_fails_soft(tmp_path: Path) -> None:
    """(c) a plain directory (no ``.git``) → ``git log`` exits
    non-zero → ``{}`` (fail-soft, no raise) — the importer falls back
    to file mtimes."""
    plain = tmp_path / "notarepo"
    plain.mkdir()
    (plain / "a.md").write_text("# A\nnot a git repo\n", encoding="utf-8")
    assert file_commit_dates(plain) == {}


def test_nonexistent_directory_fails_soft(tmp_path: Path) -> None:
    """(c) a missing checkout directory → ``{}`` without even
    invoking git (no raise)."""
    assert file_commit_dates(tmp_path / "gone") == {}


def test_empty_repo_fails_soft(tmp_path: Path) -> None:
    """(c) an initialized repo with NO commits → ``git log`` fails
    (nothing to log) → ``{}`` (a cloned-but-empty source must not
    break the sync)."""
    empty = tmp_path / "emptyrepo"
    empty.mkdir()
    _git(empty, "init", "-q")
    _git(empty, "config", "commit.gpgsign", "false")
    assert file_commit_dates(empty) == {}


def test_git_error_fails_soft(
    scratch_repo: Path, monkeypatch: pytest.MonkeyPatch, caplog: pytest.LogCaptureFixture
) -> None:
    """(c) a ``GitSyncError`` from the walk (git missing/failed) →
    ``{}`` + a logged warning naming the fallback — the fail-soft
    contract (pinned)."""

    def boom(argv: list[str], cwd: Path) -> str:
        raise GitSyncError("git log failed (exit 128): fatal: bad object")

    monkeypatch.setattr("scripts.git_sync.run_git", boom)
    with caplog.at_level("WARNING"):
        assert file_commit_dates(scratch_repo) == {}
    assert any("file_commit_dates" in record.message for record in caplog.records)


def test_malformed_log_output_fails_soft(
    scratch_repo: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """(c) ANY parse anomaly (a commit date ``fromisoformat`` cannot
    read) → ``{}`` (fail-soft) — the walk is all-or-nothing: a
    partially parsed date map would be worse than none."""
    monkeypatch.setattr(
        "scripts.git_sync.run_git",
        lambda argv, cwd: "@@not-a-date\nb.md\n",
    )
    assert file_commit_dates(scratch_repo) == {}


# --- the pure parser (canned git output — no git, no DB) -------------------


def test_parser_first_sighting_wins_newest_first() -> None:
    """The walk is newest-first, so the FIRST sighting of a path is
    its last-commit date: ``b.md`` appears under both commits and keeps
    the 2024 (newest) date; the 2020 ``a.md`` keeps 2020. Blank lines
    (git's commit separators) are skipped."""
    output = "\n".join(
        [
            "@@2024-06-15T10:00:00+00:00",
            "",
            "b.md",
            "@@2020-01-02T03:04:06+00:00",
            "",
            "a.md",
            "b.md",
        ]
    )
    assert _parse_commit_dates(output) == {"a.md": DATE_A, "b.md": DATE_B}


def test_parser_normalizes_paths() -> None:
    """Path lines are whitespace-split (defensively - git's name-only
    output is one path per line), backslash-normalized to ``/``, and a
    leading ``/`` is stripped (repo-relative POSIX keys); the line is
    stripped first."""
    output = "\n".join(
        [
            "@@2024-06-15T10:00:00+00:00",
            "",
            "docs\\deep.md",
            "/rooted.md",
            "  padded.md  ",
        ]
    )
    assert _parse_commit_dates(output) == {
        "docs/deep.md": DATE_B,
        "rooted.md": DATE_B,
        "padded.md": DATE_B,
    }


def test_parser_rejects_path_before_header() -> None:
    """A path line before ANY commit header is a malformed walk →
    ``ValueError`` (the caller's fail-soft path turns it into
    ``{}``)."""
    with pytest.raises(ValueError, match="before any commit header"):
        _parse_commit_dates("stray.md\n@@2024-06-15T10:00:00+00:00\n")


def test_parser_rejects_bad_date() -> None:
    """A commit date ``fromisoformat`` cannot read → ``ValueError``
    (ISO-strict ``%cI`` always parses — this is the anomaly guard)."""
    with pytest.raises(ValueError):
        _parse_commit_dates("@@yesterday\nb.md\n")