"""Tests for the UK bus stop finder backend."""

from __future__ import annotations

from typing import Any

import pytest
import responses

from uk_bus_stops import core
from uk_bus_stops.app import ATCO_PATTERN, create_app, parse_coordinates


@pytest.fixture()
def client() -> Any:
    """Return a Flask test client."""
    return create_app({"TESTING": True}).test_client()


@responses.activate
def test_geocode_limits_search_to_great_britain_and_identifies_app() -> None:
    """Nominatim receives the UK restriction and identifying User-Agent."""
    responses.get(
        core.NOMINATIM_URL,
        json=[{"lat": "51.45", "lon": "-2.59", "display_name": "Bristol, England"}],
    )
    result = core.geocode("Bristol")
    assert result == {"lat": 51.45, "lon": -2.59, "label": "Bristol, England"}
    request = responses.calls[0].request
    assert "countrycodes=gb" in request.url
    assert request.headers["User-Agent"].startswith("uk-bus-stops/")
    assert "edward@4angle.com" in request.headers["User-Agent"]


@responses.activate
def test_nearby_stops_normalises_deduplicates_and_orders() -> None:
    """Nearby Overpass objects become nearest-first stop records without duplicates."""
    responses.get(
        core.OVERPASS_URL,
        json={"elements": [
            {"type": "node", "id": 2, "lat": 51.46, "lon": -2.58,
             "tags": {"highway": "bus_stop", "name": "Far Stop"}},
            {"type": "node", "id": 1, "lat": 51.4501, "lon": -2.5901,
             "tags": {"naptan:CommonName": "Near Stop", "naptan:AtcoCode": "0100BRP90314",
                      "naptan:Bearing": "NW"}},
            {"type": "node", "id": 1, "lat": 51.4501, "lon": -2.5901,
             "tags": {"name": "Near Stop", "naptan:AtcoCode": "0100BRP90314",
                      "naptan:Bearing": "NW"}},
        ]},
    )
    result = core.nearby_stops(51.45, -2.59)
    assert [stop["id"] for stop in result] == [1, 2]
    assert result[0]["atco_code"] == "0100BRP90314"
    assert result[0]["transport_type"] == "Transport stop"
    assert result[0]["bearing"] == "NW"
    assert result[1]["atco_code"] is None
    assert "highway%22%3D%22bus_stop" in responses.calls[0].request.url


@responses.activate
def test_find_atco_code_is_case_insensitive() -> None:
    """Direct code lookup emits an anchored, case-insensitive Overpass query."""
    responses.get(
        core.OVERPASS_URL,
        json={"elements": [{
            "type": "node", "id": 123, "lat": 51.45, "lon": -2.59,
            "tags": {"name": "Central", "naptan:AtcoCode": "0100BRP90314"},
        }]},
    )
    result = core.find_atco_code("0100brp90314")
    assert result[0]["name"] == "Central"
    assert "%5E0100brp90314%24%22%2Ci" in responses.calls[0].request.url


@responses.activate
def test_fetch_stop_by_osm_reference() -> None:
    """A shared stop reference is resolved to normalised stop details."""
    responses.get(core.OVERPASS_URL, json={"elements": [{
        "type": "node", "id": 123, "lat": 51.45, "lon": -2.59,
        "tags": {"name": "Central", "highway": "bus_stop"},
    }]})
    stop = core.fetch_stop("node", 123)
    assert stop is not None
    assert stop["id"] == 123
    assert stop["transport_type"] == "Bus stop"


@responses.activate
def test_overpass_uses_fallback_instance() -> None:
    """An unavailable UK Overpass host is retried on the global fallback."""
    responses.get(core.OVERPASS_URL, status=503)
    responses.get(core.OVERPASS_FALLBACK_URLS[0], json={"elements": []})
    assert core.find_atco_code("0100BRP90314") == []
    assert len(responses.calls) == 2
    assert responses.calls[1].request.url.startswith(core.OVERPASS_FALLBACK_URLS[0])


@responses.activate
def test_routes_for_stop_returns_useful_route_fields() -> None:
    """Route lookup uses stop-area members and returns human-readable metadata."""
    responses.get(
        core.OVERPASS_URL,
        json={"elements": [
            {"type": "relation", "id": 9, "tags": {
                "ref": "A1", "name": "Airport bus", "operator": "Example Bus",
                "from": "Airport", "to": "City Centre",
            }},
        ]},
    )
    routes = core.routes_for_stop("node", 123)
    assert routes == [{
        "id": 9, "ref": "A1", "name": "Airport bus", "operator": "Example Bus",
        "from": "Airport", "to": "City Centre",
    }]
    query_url = responses.calls[0].request.url
    assert "stop_area" in query_url
    assert "route" in query_url


@pytest.mark.parametrize(
    ("tags", "expected"),
    [
        ({"highway": "bus_stop"}, "Bus stop"),
        ({"railway": "station"}, "Railway station"),
        ({"railway": "tram_stop"}, "Tram stop"),
        ({"station": "subway"}, "Underground station"),
        ({"amenity": "ferry_terminal"}, "Ferry terminal"),
    ],
)
def test_transport_type_classifies_osm_tags(tags: dict[str, str], expected: str) -> None:
    """Common OSM public transport tagging receives a clear display type."""
    assert core.transport_type(tags) == expected


def test_search_rejects_empty_query(client: Any) -> None:
    """The search endpoint returns the standard JSON error shape."""
    response = client.get("/api/search")
    assert response.status_code == 400
    assert response.get_json()["error"] == "missing_query"


def test_place_name_is_not_mistaken_for_atco_code() -> None:
    """Long alphabetic place names still go through Nominatim geocoding."""
    assert ATCO_PATTERN.fullmatch("Manchester") is None
    assert ATCO_PATTERN.fullmatch("0100BRP90314") is not None


def test_parse_coordinates_accepts_valid_pair_and_rejects_invalid_pair() -> None:
    """Coordinate searches require a comma and valid latitude/longitude ranges."""
    assert parse_coordinates(" 51.4545, -2.5879 ") == (51.4545, -2.5879)
    assert parse_coordinates("51.4545 -2.5879") is None
    assert parse_coordinates("91, -2") is None


@responses.activate
def test_search_coordinates_bypasses_nominatim(client: Any) -> None:
    """Latitude/longitude entered in the search endpoint goes straight to Overpass."""
    responses.get(core.OVERPASS_URL, json={"elements": []})
    response = client.get("/api/search?q=51.4545%2C+-2.5879")
    assert response.status_code == 200
    data = response.get_json()
    assert data["location"]["lat"] == 51.4545
    assert data["location"]["lon"] == -2.5879
    assert len(responses.calls) == 1
    assert responses.calls[0].request.url.startswith(core.OVERPASS_URL)


def test_location_coordinates_are_validated(client: Any) -> None:
    """Latitude and longitude must be numeric and within geographic ranges."""
    assert client.get("/api/stops?lat=hello&lon=1").status_code == 400
    assert client.get("/api/stops?lat=91&lon=1").status_code == 400


def test_map_bounds_reject_large_overpass_area(client: Any) -> None:
    """The server refuses viewport queries that are too large for Overpass."""
    response = client.get("/api/stops/in-bounds?south=50&west=-3&north=51&east=-2")
    assert response.status_code == 400
    assert response.get_json()["error"] == "area_too_large"


@responses.activate
def test_shared_stop_api(client: Any) -> None:
    """The stop detail endpoint supports refreshing a shared stop URL."""
    responses.get(core.OVERPASS_URL, json={"elements": [{
        "type": "node", "id": 123, "lat": 51.45, "lon": -2.59,
        "tags": {"name": "Central", "highway": "bus_stop"},
    }]})
    response = client.get("/api/stop/node/123")
    assert response.status_code == 200
    assert response.get_json()["stop"]["name"] == "Central"


@responses.activate
def test_map_bounds_load_small_area(client: Any) -> None:
    """A small viewport returns classified stops from Overpass."""
    responses.get(core.OVERPASS_URL, json={"elements": [{
        "type": "node", "id": 4, "lat": 51.45, "lon": -2.59,
        "tags": {"railway": "station", "name": "Temple Meads"},
    }]})
    response = client.get(
        "/api/stops/in-bounds?south=51.44&west=-2.60&north=51.46&east=-2.58"
    )
    assert response.status_code == 200
    assert response.get_json()["stops"][0]["transport_type"] == "Railway station"


def test_index_contains_search_and_map(client: Any) -> None:
    """The landing page includes the primary search and map controls."""
    response = client.get("/")
    assert response.status_code == 200
    assert b"Find a UK bus stop code" in response.data
    assert b'id="search-input"' in response.data
    assert b'id="map"' in response.data