from types import SimpleNamespace
import pytest
from fastapi.testclient import TestClient
from backend import app as api, data_loader
from backend.tests.test_sixth_form_flag import _schools_df


def client_for(monkeypatch, search):
    client = SimpleNamespace(collections={'schools': SimpleNamespace(documents=SimpleNamespace(search=search))})
    monkeypatch.setattr(data_loader, '_get_typesense_client', lambda: client)


def test_search_returns_matches_beyond_first_page(monkeypatch):
    pages = []
    def search(params):
        pages.append(params['page'])
        urns = range(100000, 100250) if params['page'] == 1 else [100999]
        return {'found': 251, 'hits': [{'document': {'urn': u}} for u in urns]}
    client_for(monkeypatch, search)
    result = data_loader.search_schools_typesense('academy')
    assert len(result) == 251
    assert result[-1] == 100999
    assert pages == [1, 2]


def test_later_page_failure_does_not_return_partial_results(monkeypatch):
    def search(params):
        if params['page'] == 2:
            raise RuntimeError('timeout')
        return {'found': 251, 'hits': [{'document': {'urn': u}} for u in range(100000, 100250)]}
    client_for(monkeypatch, search)
    assert data_loader.search_schools_typesense('academy') is None


def test_zero_matches_are_distinct_from_unavailable(monkeypatch):
    client_for(monkeypatch, lambda _: {'found': 0, 'hits': []})
    assert data_loader.search_schools_typesense('academy') == []
    monkeypatch.setattr(data_loader, '_get_typesense_client', lambda: None)
    assert data_loader.search_schools_typesense('academy') is None


@pytest.mark.parametrize('matches, expected', [([], []), (None, [100001])])
def test_fallback_only_on_dependency_failure(monkeypatch, matches, expected):
    monkeypatch.setattr(api.limiter, 'enabled', False)
    monkeypatch.setattr(api, 'load_latest_school_data', _schools_df)
    monkeypatch.setattr(api, 'search_schools_typesense', lambda _: matches)
    response = TestClient(api.app).get('/api/schools?search=Alpha')
    assert response.status_code == 200
    assert [s['urn'] for s in response.json()['schools']] == expected


def test_filtered_api_keeps_match_from_second_search_page(monkeypatch):
    monkeypatch.setattr(api.limiter, 'enabled', False)
    df = _schools_df()
    monkeypatch.setattr(api, 'load_latest_school_data', lambda: df)
    def search(params):
        urns = range(200000, 200250) if params['page'] == 1 else [100001]
        return {'found': 251, 'hits': [{'document': {'urn': u}} for u in urns]}
    client_for(monkeypatch, search)
    response = TestClient(api.app).get('/api/schools?search=Alpha&local_authority=Testshire')
    assert response.status_code == 200
    assert response.json()['total'] == 1
    assert response.json()['schools'][0]['urn'] == 100001


def test_unavailable_dataset_is_not_a_missing_school_or_empty_search(monkeypatch):
    import pandas as pd
    monkeypatch.setattr(api.limiter, 'enabled', False)
    monkeypatch.setattr(api, 'load_school_data', lambda: pd.DataFrame())
    monkeypatch.setattr(api, 'load_latest_school_data', lambda: pd.DataFrame())
    client = TestClient(api.app)
    assert client.get('/api/schools/100001').status_code == 503
    assert client.get('/api/schools?search=school').status_code == 503