"""Alpaca fetch window / feed selection.

Regression cover for the 2026-07-20 outage: the near-close scan silently ran on
the previous session's close because ``end`` resolved to midnight on end_date,
which is *before* that day's bar timestamp (04:00Z under EDT). Widening the
window also has to stay clear of the delayed-data period, which rejects the whole
request.
"""

from __future__ import annotations

from datetime import date, datetime, timedelta, timezone

import pytest

from app.providers.alpaca import AlpacaOHLCVProvider


class _CapturingClient:
    """Stands in for StockHistoricalDataClient, recording the request."""

    def __init__(self) -> None:
        self.request = None

    def get_stock_bars(self, request):
        self.request = request
        return {"AAPL": []}


def _provider() -> tuple[AlpacaOHLCVProvider, _CapturingClient]:
    provider = AlpacaOHLCVProvider("key", "secret")
    client = _CapturingClient()
    provider._client = client
    return provider, client


def _midnight(day: date) -> datetime:
    """Naive-UTC midnight — the SDK strips tzinfo from request datetimes."""
    return datetime.combine(day, datetime.min.time())


def _utcnow() -> datetime:
    return datetime.now(timezone.utc).replace(tzinfo=None)


def _utc_today() -> date:
    """The provider clamps against UTC, so the fixture must use the UTC date.

    ``date.today()`` is local and runs a day ahead in a UTC+hh timezone just
    after midnight, which would assert against a day the clamp cannot reach."""
    return datetime.now(timezone.utc).date()


@pytest.mark.asyncio
async def test_todays_in_progress_bar_is_inside_the_window():
    """The whole near-close design depends on today's bar being fetchable."""
    provider, client = _provider()
    today = _utc_today()

    await provider.fetch_ohlcv("AAPL", today - timedelta(days=5), today)

    # Daily bars are stamped at session start (04:00Z); a midnight end drops them.
    assert client.request.end > _midnight(today)


@pytest.mark.asyncio
async def test_window_stays_out_of_the_delayed_data_period():
    """A window reaching the last ~15 minutes fails the entire request."""
    provider, client = _provider()

    await provider.fetch_ohlcv("AAPL", _utc_today() - timedelta(days=5), _utc_today())

    assert client.request.end <= _utcnow() - timedelta(minutes=15)


@pytest.mark.asyncio
async def test_completed_past_day_is_fully_covered():
    """Clamping must not swallow the last day of a historical window."""
    provider, client = _provider()
    end_date = _utc_today() - timedelta(days=3)

    await provider.fetch_ohlcv("AAPL", end_date - timedelta(days=5), end_date)

    assert client.request.end > _midnight(end_date)


@pytest.mark.asyncio
async def test_window_collapsing_to_nothing_skips_the_call():
    """A start inside the delayed period yields no request at all, not an error."""
    provider, client = _provider()
    tomorrow = _utc_today() + timedelta(days=2)

    records = await provider.fetch_ohlcv("AAPL", tomorrow, tomorrow)

    assert records == []
    assert client.request is None
