"""Tests for poll() — the Schiphol API fetch-and-publish sweep."""

import pytest
import requests

from main import poll

# ---------------------------------------------------------------------------
# Test doubles
# ---------------------------------------------------------------------------


class _NoOpSpan:
    def __enter__(self):
        return self

    def __exit__(self, *args):
        pass


class StubTracer:
    def start_as_current_span(self, name, attributes=None):
        return _NoOpSpan()


class StubResponse:
    """Minimal requests.Response lookalike."""

    def __init__(self, flights, *, next_url=None, raise_on_status=False):
        self._flights = flights
        self._raise = raise_on_status
        self.headers = {}
        if next_url:
            self.headers["link"] = f'<{next_url}>; rel="next"'

    def raise_for_status(self):
        if self._raise:
            raise requests.HTTPError("500 Server Error")

    def json(self):
        return {"flights": self._flights}


class StubSession:
    """Returns pre-configured StubResponse objects keyed by URL."""

    def __init__(self, responses_by_url: dict):
        self._responses = responses_by_url

    def get(self, url):
        return self._responses[url]


class MockEngine:
    """Captures every send() call so tests can assert on Kafka output."""

    def __init__(self):
        self.sent: list[dict] = []

    async def send(self, topic, *, value, key):
        self.sent.append({"topic": topic, "value": value, "key": key})


class FakeApiSettings:
    base_url = "https://api.example.com/flights"


class FakeKafkaSettings:
    topic = "flights-test"


# ---------------------------------------------------------------------------
# Tests
# ---------------------------------------------------------------------------


async def test_single_page_publishes_all_flights_and_returns_count():
    """poll() publishes every Flight on a single-page response and returns the count."""
    flights = [{"id": "1", "flightName": "KL100"}, {"id": "2", "flightName": "KL200"}]
    session = StubSession({FakeApiSettings.base_url: StubResponse(flights)})
    engine = MockEngine()

    count = await poll(session, engine, FakeApiSettings(), FakeKafkaSettings(), StubTracer())

    assert count == 2
    assert len(engine.sent) == 2
    published_keys = {msg["key"] for msg in engine.sent}
    assert published_keys == {"1", "2"}


async def test_pagination_publishes_flights_across_all_pages():
    """poll() follows link: rel="next" headers and publishes Flights from every page."""
    page1_url = FakeApiSettings.base_url
    page2_url = "https://api.example.com/flights?page=2"

    page1_flights = [{"id": "A"}, {"id": "B"}]
    page2_flights = [{"id": "C"}, {"id": "D"}, {"id": "E"}]

    session = StubSession(
        {
            page1_url: StubResponse(page1_flights, next_url=page2_url),
            page2_url: StubResponse(page2_flights),
        }
    )
    engine = MockEngine()

    count = await poll(session, engine, FakeApiSettings(), FakeKafkaSettings(), StubTracer())

    assert count == 5
    assert len(engine.sent) == 5


async def test_http_error_propagates_out_of_poll():
    """poll() lets HTTP errors from raise_for_status() propagate to the caller."""
    session = StubSession(
        {FakeApiSettings.base_url: StubResponse([], raise_on_status=True)}
    )
    engine = MockEngine()

    with pytest.raises(requests.HTTPError):
        await poll(session, engine, FakeApiSettings(), FakeKafkaSettings(), StubTracer())