from __future__ import annotations

import base64

import pytest

from vuln_scan.github.base_client import AuthConfig
from vuln_scan.github.repo_client import GitHubRepoClient

# --------------------------------------------------------
# Fakes
# --------------------------------------------------------


class _FakeUnknownObjectException(Exception):
    pass


class _FakeGithubException(Exception):
    def __init__(self, status: int, data: dict) -> None:
        super().__init__("github error")
        self.status = status
        self.data = data


class _FakeContentFile:
    def __init__(self, content: str | None) -> None:
        self.content = content


class _FakeRepo:
    def __init__(self) -> None:
        self.default_branch = "main"
        self._content_response = None
        self._content_exception: Exception | None = None

    def get_contents(self, path: str, ref: str):
        if self._content_exception:
            raise self._content_exception
        return self._content_response


# --------------------------------------------------------
# Fixtures
# --------------------------------------------------------


@pytest.fixture
def fake_repo() -> _FakeRepo:
    return _FakeRepo()


@pytest.fixture
def client(fake_repo: _FakeRepo) -> GitHubRepoClient:
    """Pre-wired client bypassing __post_init__."""
    c = GitHubRepoClient.__new__(GitHubRepoClient)
    c._repo = fake_repo
    return c


@pytest.fixture
def _patch_content_file(monkeypatch: pytest.MonkeyPatch) -> None:
    """Patch ContentFile so isinstance checks work with _FakeContentFile."""
    monkeypatch.setattr("vuln_scan.github.repo_client.ContentFile", _FakeContentFile)


# --------------------------------------------------------
# __post_init__
# --------------------------------------------------------


def test_post_init_sets_repo_from_owner_and_name(monkeypatch: pytest.MonkeyPatch) -> None:
    fake_repo = _FakeRepo()

    class _FakeGH:
        def get_repo(self, full_name: str):
            assert full_name == "org/repo"
            return fake_repo

    monkeypatch.setattr(
        "vuln_scan.github.repo_client.GitHubBaseClient.__post_init__",
        lambda self: setattr(self, "_gh", _FakeGH()),
    )

    client = GitHubRepoClient(auth_config=AuthConfig(token="t"), owner="org", repo="repo")

    assert client._repo is fake_repo


# --------------------------------------------------------
# get_default_branch
# --------------------------------------------------------


def test_get_default_branch(client: GitHubRepoClient) -> None:
    assert client.get_default_branch() == "main"


# --------------------------------------------------------
# get_file_content — returns None cases
# --------------------------------------------------------


@pytest.mark.parametrize(
    "setup_repo, patch_ids, expected",
    [
        pytest.param(
            {"exception": _FakeUnknownObjectException("missing")},
            {"UnknownObjectException": _FakeUnknownObjectException},
            None,
            id="missing-file",
        ),
        pytest.param(
            {"response": ["dir", "items"]},
            {},
            None,
            id="directory-list",
        ),
        pytest.param(
            {"response": object()},
            {"ContentFile": _FakeContentFile},
            None,
            id="non-contentfile-type",
        ),
        pytest.param(
            {"response": _FakeContentFile(None)},
            {"ContentFile": _FakeContentFile},
            None,
            id="content-is-none",
        ),
        pytest.param(
            {"response": _FakeContentFile(base64.b64encode(b"hello world").decode())},
            {"ContentFile": _FakeContentFile},
            "hello world",
            id="decodes-base64-content",
        ),
    ],
)
def test_get_file_content(
    monkeypatch: pytest.MonkeyPatch,
    fake_repo: _FakeRepo,
    client: GitHubRepoClient,
    setup_repo: dict,
    patch_ids: dict,
    expected: str | None,
) -> None:
    if "exception" in setup_repo:
        fake_repo._content_exception = setup_repo["exception"]
    if "response" in setup_repo:
        fake_repo._content_response = setup_repo["response"]

    for attr, fake_cls in patch_ids.items():
        monkeypatch.setattr(f"vuln_scan.github.repo_client.{attr}", fake_cls)

    assert client.get_file_content("a.txt", "main") == expected


# --------------------------------------------------------
# get_file_content — re-raises GithubException
# --------------------------------------------------------


def test_get_file_content_reraises_github_exception(
    monkeypatch: pytest.MonkeyPatch,
    fake_repo: _FakeRepo,
    client: GitHubRepoClient,
) -> None:
    monkeypatch.setattr("vuln_scan.github.repo_client.GithubException", _FakeGithubException)
    fake_repo._content_exception = _FakeGithubException(500, {"message": "oops"})

    with pytest.raises(_FakeGithubException):
        client.get_file_content("a.txt", "main")