"""
Tests for BATON-FIX-007: CORS OPTIONS preflight verification.

Acceptance criteria:
1. OPTIONS preflight to /api/signal returns 200.
2. Preflight response includes Access-Control-Allow-Methods containing GET.
3. Preflight response includes Access-Control-Allow-Origin matching the configured origin.
4. Preflight response includes Access-Control-Allow-Headers with Authorization.
5. allow_methods in CORSMiddleware configuration explicitly contains GET.
"""
from __future__ import annotations

import ast
from pathlib import Path

import pytest

from tests.conftest import make_app_client

_FRONTEND_ORIGIN = "http://localhost:3000"
_BACKEND_DIR = Path(__file__).parent.parent / "backend"

# ---------------------------------------------------------------------------
# Static check — CORSMiddleware config contains GET in allow_methods
# ---------------------------------------------------------------------------


def test_main_py_cors_allow_methods_contains_get() -> None:
    """allow_methods в CORSMiddleware должен содержать 'GET'."""
    source = (_BACKEND_DIR / "main.py").read_text(encoding="utf-8")
    tree = ast.parse(source, filename="main.py")

    for node in ast.walk(tree):
        if isinstance(node, ast.Call):
            func = node.func
            if isinstance(func, ast.Name) and func.id == "add_middleware":
                continue
            if not (
                isinstance(func, ast.Attribute) and func.attr == "add_middleware"
            ):
                continue
            for kw in node.keywords:
                if kw.arg == "allow_methods":
                    if isinstance(kw.value, ast.List):
                        methods = [
                            elt.value
                            for elt in kw.value.elts
                            if isinstance(elt, ast.Constant) and isinstance(elt.value, str)
                        ]
                        assert "GET" in methods, (
                            f"allow_methods в CORSMiddleware не содержит 'GET': {methods}"
                        )
                        return

    pytest.fail("add_middleware с CORSMiddleware и allow_methods не найден в main.py")


def test_main_py_cors_allow_methods_contains_post() -> None:
    """allow_methods в CORSMiddleware должен содержать 'POST' (регрессия)."""
    source = (_BACKEND_DIR / "main.py").read_text(encoding="utf-8")
    assert '"POST"' in source or "'POST'" in source, (
        "allow_methods в CORSMiddleware не содержит 'POST'"
    )


# ---------------------------------------------------------------------------
# Functional — OPTIONS preflight request
# ---------------------------------------------------------------------------


@pytest.mark.asyncio
async def test_options_preflight_signal_returns_200() -> None:
    """OPTIONS preflight к /api/signal должен возвращать 200."""
    async with make_app_client() as client:
        resp = await client.options(
            "/api/signal",
            headers={
                "Origin": _FRONTEND_ORIGIN,
                "Access-Control-Request-Method": "POST",
                "Access-Control-Request-Headers": "Content-Type, Authorization",
            },
        )
    assert resp.status_code == 200, (
        f"Preflight OPTIONS /api/signal вернул {resp.status_code}, ожидался 200"
    )


@pytest.mark.asyncio
async def test_options_preflight_allow_origin_header() -> None:
    """OPTIONS preflight должен вернуть Access-Control-Allow-Origin."""
    async with make_app_client() as client:
        resp = await client.options(
            "/api/signal",
            headers={
                "Origin": _FRONTEND_ORIGIN,
                "Access-Control-Request-Method": "POST",
                "Access-Control-Request-Headers": "Content-Type, Authorization",
            },
        )
    acao = resp.headers.get("access-control-allow-origin", "")
    assert acao == _FRONTEND_ORIGIN, (
        f"Ожидался Access-Control-Allow-Origin: {_FRONTEND_ORIGIN!r}, получен: {acao!r}"
    )


@pytest.mark.asyncio
async def test_options_preflight_allow_methods_contains_get() -> None:
    """OPTIONS preflight должен вернуть Access-Control-Allow-Methods, включающий GET."""
    async with make_app_client() as client:
        resp = await client.options(
            "/api/signal",
            headers={
                "Origin": _FRONTEND_ORIGIN,
                "Access-Control-Request-Method": "GET",
                "Access-Control-Request-Headers": "Authorization",
            },
        )
    acam = resp.headers.get("access-control-allow-methods", "")
    assert "GET" in acam, (
        f"Access-Control-Allow-Methods не содержит GET: {acam!r}\n"
        "Decision #1268: allow_methods=['POST'] — GET отсутствует"
    )


@pytest.mark.asyncio
async def test_options_preflight_allow_headers_contains_authorization() -> None:
    """OPTIONS preflight должен вернуть Access-Control-Allow-Headers, включающий Authorization."""
    async with make_app_client() as client:
        resp = await client.options(
            "/api/signal",
            headers={
                "Origin": _FRONTEND_ORIGIN,
                "Access-Control-Request-Method": "POST",
                "Access-Control-Request-Headers": "Authorization",
            },
        )
    acah = resp.headers.get("access-control-allow-headers", "")
    assert "authorization" in acah.lower(), (
        f"Access-Control-Allow-Headers не содержит Authorization: {acah!r}"
    )


@pytest.mark.asyncio
async def test_get_health_cors_header_present() -> None:
    """GET /health с Origin должен вернуть Access-Control-Allow-Origin (simple request)."""
    async with make_app_client() as client:
        resp = await client.get(
            "/health",
            headers={"Origin": _FRONTEND_ORIGIN},
        )
    assert resp.status_code == 200
    acao = resp.headers.get("access-control-allow-origin", "")
    assert acao == _FRONTEND_ORIGIN, (
        f"GET /health: ожидался CORS-заголовок {_FRONTEND_ORIGIN!r}, получен: {acao!r}"
    )