"""/api/v2/narrative — the read-only half of the plain-English day summaries.

The load-bearing assertion here is the negative one: this route must never reach
for a model. ``narrator.generate`` is replaced with a bomb for every test, so any
future edit that makes the request path call inference fails loudly instead of
quietly coupling a public endpoint to a desktop GPU.
"""
import datetime

import pytest
from fastapi.testclient import TestClient

from data import grid
from data import narrator
from data import store
from web import app as appmod

Q = {"lat": 47.6062, "lon": -122.3321}
TODAY = datetime.date.today()


@pytest.fixture
def client(monkeypatch):
    def _boom(*a, **kw):  # pragma: no cover - failing here is the point
        raise AssertionError("the request path must never call the LLM")
    monkeypatch.setattr(narrator, "generate", _boom)
    return TestClient(appmod.app)


@pytest.fixture
def seeded():
    """Store one narrative for today's cell and hand back its identity."""
    cell = grid.snap(Q["lat"], Q["lon"])
    key = narrator.narrative_key(TODAY)
    token = narrator.narrative_token()
    store.put_narrative(cell["id"], key, token,
                        "A cool night for late July here.", "qwen3:14b")
    yield {"cell": cell, "key": key, "token": token}


def test_missing_narrative_is_pending_not_an_error(client):
    r = client.get("/thermograph/api/v2/narrative",
                   params={"lat": -33.8688, "lon": 151.2093})
    assert r.status_code == 200
    body = r.json()
    assert body["narrative"] is None
    assert body["status"] == "pending"
    assert body["model"] is None


def test_stored_narrative_is_served_with_provenance(client, seeded):
    r = client.get("/thermograph/api/v2/narrative", params=Q)
    assert r.status_code == 200
    body = r.json()
    assert body["narrative"] == "A cool night for late July here."
    assert body["status"] == "ready"
    assert body["model"] == "qwen3:14b"
    assert body["generated_at"] > 0
    assert body["date"] == TODAY.isoformat()
    assert body["cell"]["id"] == seeded["cell"]["id"]


def test_conditional_revalidation_returns_304(client, seeded):
    first = client.get("/thermograph/api/v2/narrative", params=Q)
    etag = first.headers["ETag"]
    again = client.get("/thermograph/api/v2/narrative", params=Q,
                       headers={"If-None-Match": etag})
    assert again.status_code == 304
    assert again.content == b""


def test_the_pending_etag_changes_once_the_row_lands(client, seeded):
    """A client that cached a pending response has to notice the sentence
    appearing — so the two states must not share an ETag."""
    ready = client.get("/thermograph/api/v2/narrative", params=Q).headers["ETag"]
    pending = client.get("/thermograph/api/v2/narrative",
                         params={"lat": -33.8688, "lon": 151.2093}).headers["ETag"]
    assert ready != pending


def test_a_row_written_under_another_token_is_not_served(client):
    """A prompt or model change must orphan old text rather than serve it."""
    cell = grid.snap(35.6762, 139.6503)
    store.put_narrative(cell["id"], narrator.narrative_key(TODAY),
                        "n0:some-old-model", "Written under the old contract.",
                        "some-old-model")
    r = client.get("/thermograph/api/v2/narrative",
                   params={"lat": 35.6762, "lon": 139.6503})
    assert r.status_code == 200
    assert r.json()["narrative"] is None
    assert r.json()["status"] == "pending"


def test_an_explicit_past_date_is_its_own_row(client, seeded):
    r = client.get("/thermograph/api/v2/narrative",
                   params={**Q, "date": "2020-01-01"})
    assert r.status_code == 200
    assert r.json()["date"] == "2020-01-01"
    assert r.json()["narrative"] is None


def test_an_unparseable_date_is_rejected(client):
    r = client.get("/thermograph/api/v2/narrative", params={**Q, "date": "last-tuesday"})
    assert r.status_code == 400


@pytest.mark.parametrize("bad", [{"lat": 91, "lon": 0}, {"lat": 0, "lon": 181}])
def test_out_of_range_coordinates_are_rejected(client, bad):
    assert client.get("/thermograph/api/v2/narrative", params=bad).status_code == 422