"""Unit tests for agent_team.ci_fetcher — the read-only, fail-closed CI fetcher.

The fetcher is a pure DATA seam: on a clean authenticated run it returns the
``{run_id, conclusion, diff_hash}`` mapping the pure-code gate consumes; on ANY
error (404 / auth fail / malformed body / timeout / missing run_id / missing
token) it returns ``None`` so the gate BLOCKs (fail-closed). It NEVER derives a
verdict and NEVER writes. Everything is mocked with a fake HTTP client; no
network, no real token.
"""

from __future__ import annotations

import pytest

from agent_team.ci_fetcher import (
    CI_READ_TOKEN_ENV,
    build_ci_result_fetcher,
    fetch_ci_result,
)


class _FakeResponse:
    def __init__(self, status: int, body):
        self.status_code = status
        self._body = body

    def json(self):
        if isinstance(self._body, Exception):
            raise self._body
        return self._body


class _FakeClient:
    """A requests-like client recording calls; raises only write verbs if asked."""

    def __init__(self, response=None, raise_exc=None):
        self._response = response
        self._raise = raise_exc
        self.calls: list[tuple[str, dict]] = []

    def get(self, url, *, timeout=None):
        self.calls.append((url, {"timeout": timeout}))
        if self._raise is not None:
            raise self._raise
        return self._response

    # If the fetcher ever tried to write, these would record it — they must not
    # be called (the fetcher is read-only).
    def post(self, *a, **k):  # pragma: no cover - must never be called
        raise AssertionError("ci_fetcher must never POST")

    def patch(self, *a, **k):  # pragma: no cover - must never be called
        raise AssertionError("ci_fetcher must never PATCH")


def _state(run_id="123", diff_hash="abc123"):
    return {"run_id": run_id, "diff_hash": diff_hash}


# --------------------------------------------------------------------------- #
# Success path
# --------------------------------------------------------------------------- #


def test_success_returns_correct_mapping() -> None:
    client = _FakeClient(
        _FakeResponse(200, {"id": 123, "conclusion": "success", "status": "completed"})
    )
    out = fetch_ci_result(_state(), owner="o", repo="r", client=client)
    assert out == {"run_id": "123", "conclusion": "success", "diff_hash": "abc123"}
    # It hit the runs endpoint for the right run, read-only.
    assert client.calls[0][0].endswith("/repos/o/r/actions/runs/123")


def test_failure_conclusion_is_echoed_not_judged() -> None:
    # The fetcher returns the raw conclusion; it does NOT decide pass/fail.
    client = _FakeClient(_FakeResponse(200, {"id": 5, "conclusion": "failure"}))
    out = fetch_ci_result(_state(run_id="5"), owner="o", repo="r", client=client)
    assert out is not None
    assert out["conclusion"] == "failure"  # echoed verbatim, no verdict derived


def test_diff_hash_echoed_from_state() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 9, "conclusion": "success"}))
    out = fetch_ci_result(
        {"run_id": "9", "diff_hash": "DEADBEEF"}, owner="o", repo="r", client=client
    )
    assert out["diff_hash"] == "DEADBEEF"


def test_run_id_read_from_state_drives_url() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 777, "conclusion": "success"}))
    fetch_ci_result(_state(run_id="777"), owner="acme", repo="svc", client=client)
    assert client.calls[0][0].endswith("/repos/acme/svc/actions/runs/777")


# --------------------------------------------------------------------------- #
# Fail-closed paths (every error -> None)
# --------------------------------------------------------------------------- #


def test_404_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(404, {"message": "Not Found"}))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_auth_fail_401_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(401, {"message": "Bad credentials"}))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_forbidden_403_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(403, {"message": "forbidden"}))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_malformed_body_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(200, ValueError("not json")))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_non_object_body_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(200, ["not", "a", "dict"]))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_missing_conclusion_fails_closed() -> None:
    # In-progress run: conclusion is None -> not an authenticated verdict.
    client = _FakeClient(_FakeResponse(200, {"id": 1, "conclusion": None}))
    assert (
        fetch_ci_result(_state(run_id="1"), owner="o", repo="r", client=client) is None
    )


def test_timeout_fails_closed() -> None:
    client = _FakeClient(raise_exc=TimeoutError("timed out"))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_connection_error_fails_closed() -> None:
    client = _FakeClient(raise_exc=ConnectionError("refused"))
    assert fetch_ci_result(_state(), owner="o", repo="r", client=client) is None


def test_missing_run_id_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 1, "conclusion": "success"}))
    assert (
        fetch_ci_result({"diff_hash": "x"}, owner="o", repo="r", client=client) is None
    )
    # And it never even made a request.
    assert client.calls == []


def test_empty_run_id_fails_closed() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 1, "conclusion": "success"}))
    assert (
        fetch_ci_result(
            {"run_id": "", "diff_hash": "x"}, owner="o", repo="r", client=client
        )
        is None
    )
    assert client.calls == []


# --------------------------------------------------------------------------- #
# Missing token (no injected client) -> fails closed (does NOT raise)
# --------------------------------------------------------------------------- #


def test_missing_token_fails_closed(monkeypatch: pytest.MonkeyPatch) -> None:
    monkeypatch.delenv(CI_READ_TOKEN_ENV, raising=False)
    monkeypatch.delenv("GITHUB_TOKEN", raising=False)
    # No client injected -> it must resolve a token; none set -> None (no raise).
    assert fetch_ci_result(_state(), owner="o", repo="r") is None


# --------------------------------------------------------------------------- #
# Read-only contract: never derives a verdict, never writes
# --------------------------------------------------------------------------- #


def test_fetcher_never_returns_a_verdict_field() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 2, "conclusion": "failure"}))
    out = fetch_ci_result(_state(run_id="2"), owner="o", repo="r", client=client)
    assert out is not None
    # The mapping is DATA only — there is no gate_decision / passed / verdict.
    assert set(out.keys()) == {"run_id", "conclusion", "diff_hash"}
    assert "passed" not in out
    assert "gate_decision" not in out


def test_build_ci_result_fetcher_returns_state_callable() -> None:
    client = _FakeClient(_FakeResponse(200, {"id": 3, "conclusion": "success"}))
    fetcher = build_ci_result_fetcher(owner="o", repo="r", client=client)
    out = fetcher({"run_id": "3", "diff_hash": "h"})
    assert out == {"run_id": "3", "conclusion": "success", "diff_hash": "h"}


def test_build_ci_result_fetcher_fails_closed_on_error() -> None:
    client = _FakeClient(_FakeResponse(500, {"message": "boom"}))
    fetcher = build_ci_result_fetcher(owner="o", repo="r", client=client)
    assert fetcher({"run_id": "3", "diff_hash": "h"}) is None