from __future__ import annotations

import logging
from pathlib import Path
from unittest.mock import MagicMock

import pytest
from git import GitCommandError, InvalidGitRepositoryError, Repo

from tenbackward.blog import (
    BACKOFF_BASE_SECONDS,
    BlogRepoError,
    DEFAULT_BLOG_SUBDIR,
    DEFAULT_REPO_URL,
    blog_dir,
    blog_repo_url,
    ensure_repo,
)


def _git_err(stderr: str = "boom") -> GitCommandError:
    return GitCommandError(["git"], stderr=stderr, status=1)


def test_blog_dir_default_subdir(tmp_path: Path) -> None:
    assert blog_dir(tmp_path) == tmp_path / DEFAULT_BLOG_SUBDIR


def test_blog_repo_url_default(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.delenv("BLOG_REPO_URL", raising=False)
    assert blog_repo_url() == DEFAULT_REPO_URL


def test_blog_repo_url_env_override(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.setenv("BLOG_REPO_URL", "https://example.com/repo.git")
    assert blog_repo_url() == "https://example.com/repo.git"


def test_ensure_repo_clones_when_missing(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    target = tmp_path / "blog"
    fake_repo = MagicMock(spec=Repo)
    calls: list[tuple[str, str]] = []

    def fake_clone_from(url: str, path: str) -> Repo:
        calls.append((url, path))
        target.mkdir(parents=True)
        (target / ".git").mkdir()
        return fake_repo

    monkeypatch.setattr("tenbackward.blog.Repo.clone_from", fake_clone_from)
    sleeps: list[float] = []
    result = ensure_repo(
        tmp_path,
        repo_url="https://example.com/repo.git",
        blog_path=target,
        max_retries=2,
        sleep=sleeps.append,
    )
    assert result is fake_repo
    assert calls == [("https://example.com/repo.git", str(target))]
    assert sleeps == []


def test_ensure_repo_pulls_when_clone_exists(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    target = tmp_path / "blog"
    target.mkdir()
    (target / ".git").mkdir()

    fake_repo = MagicMock(spec=Repo)
    monkeypatch.setattr("tenbackward.blog.Repo", MagicMock(return_value=fake_repo))

    fetch_impl = MagicMock()
    pull_impl = MagicMock()
    sleeps: list[float] = []

    result = ensure_repo(
        tmp_path,
        repo_url="https://example.com/repo.git",
        blog_path=target,
        max_retries=3,
        sleep=sleeps.append,
        fetch_impl=lambda r: fetch_impl,
        pull_impl=lambda r: pull_impl,
    )

    assert result is fake_repo
    fetch_impl.assert_called_once_with()
    pull_impl.assert_called_once_with()
    assert sleeps == []


def test_ensure_repo_aborts_on_local_modifications(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
    caplog: pytest.LogCaptureFixture,
) -> None:
    target = tmp_path / "blog"
    target.mkdir()
    (target / ".git").mkdir()

    fake_repo = MagicMock(spec=Repo)
    monkeypatch.setattr("tenbackward.blog.Repo", MagicMock(return_value=fake_repo))

    fetch_impl = MagicMock()
    pull_impl = MagicMock(
        side_effect=_git_err("Your local changes to 'foo' would be overwritten by merge")
    )
    sleeps: list[float] = []

    with caplog.at_level(logging.ERROR):
        with pytest.raises(BlogRepoError, match="local modifications"):
            ensure_repo(
                tmp_path,
                repo_url="https://example.com/repo.git",
                blog_path=target,
                max_retries=5,
                sleep=sleeps.append,
                fetch_impl=lambda r: fetch_impl,
                pull_impl=lambda r: pull_impl,
            )

    assert fetch_impl.call_count == 1
    assert pull_impl.call_count == 1
    assert sleeps == []


def test_ensure_repo_retries_transient_error_then_succeeds(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    target = tmp_path / "blog"
    target.mkdir()
    (target / ".git").mkdir()

    fake_repo = MagicMock(spec=Repo)
    monkeypatch.setattr("tenbackward.blog.Repo", MagicMock(return_value=fake_repo))

    fetch_impl = MagicMock(side_effect=[_git_err("Could not resolve host"), None])
    pull_impl = MagicMock()
    sleeps: list[float] = []

    ensure_repo(
        tmp_path,
        repo_url="https://example.com/repo.git",
        blog_path=target,
        max_retries=5,
        sleep=sleeps.append,
        fetch_impl=lambda r: fetch_impl,
        pull_impl=lambda r: pull_impl,
    )

    assert fetch_impl.call_count == 2
    pull_impl.assert_called_once_with()
    assert sleeps == [BACKOFF_BASE_SECONDS ** 1]


def test_ensure_repo_raises_after_exhausted_retries(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    target = tmp_path / "blog"
    target.mkdir()
    (target / ".git").mkdir()

    fake_repo = MagicMock(spec=Repo)
    monkeypatch.setattr("tenbackward.blog.Repo", MagicMock(return_value=fake_repo))

    fetch_impl = MagicMock(side_effect=_git_err("Could not resolve host"))
    pull_impl = MagicMock()
    sleeps: list[float] = []

    with pytest.raises(BlogRepoError, match="blog fetch/pull failed"):
        ensure_repo(
            tmp_path,
            repo_url="https://example.com/repo.git",
            blog_path=target,
            max_retries=2,
            sleep=sleeps.append,
            fetch_impl=lambda r: fetch_impl,
            pull_impl=lambda r: pull_impl,
        )

    assert fetch_impl.call_count == 3
    pull_impl.assert_not_called()
    assert sleeps == [BACKOFF_BASE_SECONDS ** 1, BACKOFF_BASE_SECONDS ** 2]


def test_ensure_repo_invalid_clone_dir_raises(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    target = tmp_path / "blog"
    target.mkdir()
    (target / "not-a-repo.txt").write_text("hi")

    def fake_repo(_path: str) -> Repo:
        raise InvalidGitRepositoryError(f"{_path} is not a repo")

    monkeypatch.setattr("tenbackward.blog.Repo", fake_repo)

    with pytest.raises(BlogRepoError, match="not a valid git repository"):
        ensure_repo(
            tmp_path,
            repo_url="https://example.com/repo.git",
            blog_path=target,
            max_retries=0,
        )