# tests/test_github_tool.py
import concurrent.futures
from pathlib import Path
from unittest.mock import MagicMock, patch

import pytest

from app.tools.github_tool import (
    _get_dir_size_mb,
    clone_repository,
    delete_repository,
    get_changed_files,
    resolve_remote_head_sha,
)


# ── _get_dir_size_mb ──────────────────────────────────────────────────────────


def test_get_dir_size_mb_sums_file_sizes(tmp_path: Path) -> None:
    (tmp_path / "a.txt").write_bytes(b"x" * 1024)
    (tmp_path / "b.txt").write_bytes(b"x" * 1024)
    size = _get_dir_size_mb(tmp_path)
    assert size == pytest.approx(2 / 1024, rel=0.01)


# ── get_changed_files ─────────────────────────────────────────────────────────


def test_get_changed_files_returns_py_files(tmp_path: Path) -> None:
    (tmp_path / "changed.py").write_text("x = 1")
    mock_result = MagicMock()
    mock_result.returncode = 0
    mock_result.stdout = "changed.py\nREADME.md\n"

    with patch("app.tools.github_tool.subprocess.run", return_value=mock_result):
        files = get_changed_files(str(tmp_path), "abc123", "def456")

    assert files == [str(tmp_path / "changed.py") if False else "changed.py"]
    # only .py files that exist on disk are returned
    assert all(f.endswith(".py") for f in files)


def test_get_changed_files_returns_empty_on_git_error() -> None:
    mock_result = MagicMock()
    mock_result.returncode = 1

    with patch("app.tools.github_tool.subprocess.run", return_value=mock_result):
        files = get_changed_files("/fake/path", "abc", "def")

    assert files == []


def test_get_changed_files_filters_nonexistent_files(tmp_path: Path) -> None:
    mock_result = MagicMock()
    mock_result.returncode = 0
    mock_result.stdout = "ghost.py\n"  # file does NOT exist on disk

    with patch("app.tools.github_tool.subprocess.run", return_value=mock_result):
        files = get_changed_files(str(tmp_path), "abc", "def")

    assert files == []


# ── clone_repository ──────────────────────────────────────────────────────────


def test_clone_repository_rejects_invalid_url() -> None:
    with pytest.raises(ValueError, match="Invalid GitHub URL"):
        clone_repository("https://gitlab.com/owner/repo")


def test_clone_repository_strips_dot_git_suffix(tmp_path: Path) -> None:
    with (
        patch("app.tools.github_tool.settings") as mock_settings,
        patch("app.tools.github_tool.Repo.clone_from"),
        patch("app.tools.github_tool._get_dir_size_mb", return_value=1.0),
    ):
        mock_settings.repo_clone_dir = str(tmp_path)
        mock_settings.max_repo_size_mb = 300

        result = clone_repository("https://github.com/owner/myrepo.git")

    assert "myrepo" in result
    assert ".git" not in Path(result).name


def test_clone_repository_success(tmp_path: Path) -> None:
    with (
        patch("app.tools.github_tool.settings") as mock_settings,
        patch("app.tools.github_tool.Repo.clone_from"),
        patch("app.tools.github_tool._get_dir_size_mb", return_value=10.0),
    ):
        mock_settings.repo_clone_dir = str(tmp_path)
        mock_settings.max_repo_size_mb = 300

        result = clone_repository("https://github.com/owner/repo")

    assert "repo" in result


def test_clone_repository_raises_on_timeout(tmp_path: Path) -> None:
    def slow_clone(*args: object, **kwargs: object) -> None:
        raise concurrent.futures.TimeoutError()

    with (
        patch("app.tools.github_tool.settings") as mock_settings,
        patch("app.tools.github_tool.Repo.clone_from", side_effect=slow_clone),
        patch("app.tools.github_tool._get_dir_size_mb", return_value=1.0),
    ):
        mock_settings.repo_clone_dir = str(tmp_path)
        mock_settings.max_repo_size_mb = 300

        with pytest.raises(TimeoutError, match="timed out"):
            clone_repository("https://github.com/owner/repo")


def test_clone_repository_raises_on_clone_error(tmp_path: Path) -> None:
    with (
        patch("app.tools.github_tool.settings") as mock_settings,
        patch(
            "app.tools.github_tool.Repo.clone_from",
            side_effect=RuntimeError("auth failed"),
        ),
    ):
        mock_settings.repo_clone_dir = str(tmp_path)
        mock_settings.max_repo_size_mb = 300

        with pytest.raises(RuntimeError, match="auth failed"):
            clone_repository("https://github.com/owner/repo")


def test_clone_repository_raises_when_too_large(tmp_path: Path) -> None:
    with (
        patch("app.tools.github_tool.settings") as mock_settings,
        patch("app.tools.github_tool.Repo.clone_from"),
        patch("app.tools.github_tool._get_dir_size_mb", return_value=999.0),
    ):
        mock_settings.repo_clone_dir = str(tmp_path)
        mock_settings.max_repo_size_mb = 300

        with pytest.raises(ValueError, match="exceeds limit"):
            clone_repository("https://github.com/owner/repo")


# ── delete_repository ─────────────────────────────────────────────────────────


def test_delete_repository_removes_existing_path(tmp_path: Path) -> None:
    target = tmp_path / "cloned_repo"
    target.mkdir()
    (target / "file.py").write_text("x = 1")

    delete_repository(str(target))

    assert not target.exists()


def test_delete_repository_is_noop_for_missing_path(tmp_path: Path) -> None:
    missing = str(tmp_path / "does_not_exist")
    delete_repository(missing)  # must not raise

# ── resolve_remote_head_sha ─────────────────────────────────────────────────


def test_resolve_remote_head_sha_returns_sha_on_success() -> None:
    mock_result = MagicMock()
    mock_result.returncode = 0
    mock_result.stdout = "abc123def456\tHEAD\n"

    with patch("app.tools.github_tool.subprocess.run", return_value=mock_result):
        sha = resolve_remote_head_sha("https://github.com/owner/repo")

    assert sha == "abc123def456"


def test_resolve_remote_head_sha_returns_none_on_git_error() -> None:
    mock_result = MagicMock()
    mock_result.returncode = 1
    mock_result.stdout = ""

    with patch("app.tools.github_tool.subprocess.run", return_value=mock_result):
        sha = resolve_remote_head_sha("https://github.com/owner/repo")

    assert sha is None


def test_resolve_remote_head_sha_returns_none_on_exception() -> None:
    with patch("app.tools.github_tool.subprocess.run", side_effect=OSError("boom")):
        sha = resolve_remote_head_sha("https://github.com/owner/repo")

    assert sha is None