from datetime import datetime, timedelta, timezone

import pytest

import nightscout_client as ns


class FakeResponse:
    def __init__(self, payload):
        self._payload = payload

    def raise_for_status(self):
        pass

    def json(self):
        return self._payload


def test_mgdl_to_mmol_converts_correctly():
    assert ns.mgdl_to_mmol(126.0) == pytest.approx(7.0, abs=0.05)


def test_base_url_requires_nightscout_url(monkeypatch):
    monkeypatch.delenv("NIGHTSCOUT_URL", raising=False)
    with pytest.raises(ns.NightscoutConfigError):
        ns._base_url()


def test_base_url_strips_trailing_slash(monkeypatch):
    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com/")
    assert ns._base_url() == "https://example.com"


def test_auth_prefers_token_over_api_secret(monkeypatch):
    monkeypatch.setenv("NIGHTSCOUT_TOKEN", "my-token")
    monkeypatch.setenv("NIGHTSCOUT_API_SECRET", "my-secret")
    headers, params = ns._auth()
    assert params == {"token": "my-token"}
    assert headers == {}


def test_auth_hashes_api_secret(monkeypatch):
    monkeypatch.delenv("NIGHTSCOUT_TOKEN", raising=False)
    monkeypatch.setenv("NIGHTSCOUT_API_SECRET", "my-secret")
    headers, params = ns._auth()
    assert params == {}
    assert headers["API-SECRET"] != "my-secret"  # nooit in plaintext
    assert len(headers["API-SECRET"]) == 40  # sha1 hexdigest


def test_fetch_entries_converts_and_filters_by_time(monkeypatch):
    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com")
    monkeypatch.delenv("NIGHTSCOUT_TOKEN", raising=False)
    monkeypatch.delenv("NIGHTSCOUT_API_SECRET", raising=False)

    now = datetime.now(timezone.utc)
    recent = now - timedelta(hours=1)
    too_old = now - timedelta(hours=48)
    payload = [
        {"date": int(recent.timestamp() * 1000), "sgv": 126},
        {"date": int(too_old.timestamp() * 1000), "sgv": 90},
    ]

    monkeypatch.setattr(ns.requests, "get", lambda *a, **k: FakeResponse(payload))

    result = ns.fetch_entries(hours=24)
    assert len(result) == 1
    assert result.iloc[0]["mmol"] == pytest.approx(7.0, abs=0.05)


def test_fetch_entries_handles_empty_response(monkeypatch):
    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com")
    monkeypatch.setattr(ns.requests, "get", lambda *a, **k: FakeResponse([]))

    result = ns.fetch_entries(hours=24)
    assert result.empty
    assert list(result.columns) == ["timestamp", "mmol"]


def test_fetch_treatments_fills_missing_columns(monkeypatch):
    monkeypatch.setenv("NIGHTSCOUT_URL", "https://example.com")
    now = datetime.now(timezone.utc)
    payload = [
        {"created_at": now.isoformat(), "eventType": "Site Change"},
    ]
    monkeypatch.setattr(ns.requests, "get", lambda *a, **k: FakeResponse(payload))

    result = ns.fetch_treatments(hours=24)
    assert len(result) == 1
    assert result.iloc[0]["eventType"] == "Site Change"
    assert pd_isna(result.iloc[0]["insulin"])
    assert pd_isna(result.iloc[0]["carbs"])


def pd_isna(value):
    import pandas as pd

    return pd.isna(value)