'''
Deterministic history-backfill regressions.

'''
from functools import partial
from types import SimpleNamespace

import numpy as np
from pendulum import datetime
import trio

from piker.brokers import DataUnavailable
from piker.data._source import def_iohlcv_fields
from piker.tsp._history import start_backfill


def run_exhausted_backfill(get_hist) -> None:
    '''
    Run a provider-exhaustion case without actor services.

    '''
    async def main() -> None:
        with trio.fail_after(0.5):
            async with trio.open_nursery() as nursery:
                await nursery.start(partial(
                    start_backfill,
                    get_hist=get_hist,
                    def_frame_duration=None,
                    mod=SimpleNamespace(name='fake'),
                    mkt=SimpleNamespace(fqme='x.fake'),
                    shm=object(),
                    timeframe=60,
                    backfill_from_shm_index=100,
                    backfill_from_dt=datetime(2026, 1, 2),
                    sampler_stream=object(),
                    backfill_until_dt=datetime(2026, 1, 1),
                    storage=None,
                    write_tsdb=False,
                ))

    trio.run(main)


def test_data_unavailable_completes() -> None:
    '''
    Provider exhaustion exits without orphaned completion waits.

    '''
    async def get_hist(*args, **kwargs):
        raise DataUnavailable('history exhausted')

    run_exhausted_backfill(get_hist)


def test_empty_frame_completes() -> None:
    '''
    An empty provider frame is checked before endpoint indexing.

    '''
    frame = np.empty(
        0,
        dtype=np.dtype(def_iohlcv_fields),
    )

    async def get_hist(*args, **kwargs):
        end_dt = kwargs['end_dt']
        return frame, end_dt, end_dt

    run_exhausted_backfill(get_hist)