# Copyright (c) 2026 Krzysztof Rudnicki. MIT licence.
"""The daily tally report.

Time is injected so the tests assert on the computed interval instead of
sleeping through it.
"""

from __future__ import annotations

import datetime as dt
import logging
from collections.abc import Awaitable, Callable

logger = logging.getLogger(__name__)

Clock = Callable[[], dt.datetime]
Sleeper = Callable[[float], Awaitable[None]]
Action = Callable[[], Awaitable[None]]

SECONDS_PER_DAY = 24 * 60 * 60


class DailyScheduler:
    """Runs one action at a fixed local wall-clock time, every day."""

    def __init__(
        self,
        hour: int,
        minute: int,
        action: Action,
        clock: Clock,
        sleeper: Sleeper,
    ) -> None:
        """Store the target time, the action, and the injected time sources."""
        self._hour = hour
        self._minute = minute
        self._action = action
        self._clock = clock
        self._sleep = sleeper

    def seconds_until_next(self, now: dt.datetime) -> float:
        """Seconds from now until the next occurrence of the target time.

        Rolls over to tomorrow when today's target has already passed, so the
        result is always strictly positive.
        """
        target = now.replace(hour=self._hour, minute=self._minute, second=0, microsecond=0)
        if target <= now:
            target += dt.timedelta(days=1)
        return (target - now).total_seconds()

    async def run(self, iterations: int | None = None) -> None:
        """Sleep until the target time and run the action, forever by default.

        Args:
            iterations: Stop after this many runs. None means run forever.
                The tests use a finite count; production passes None.
        """
        completed = 0
        while iterations is None or completed < iterations:
            await self._sleep(self.seconds_until_next(self._clock()))
            try:
                await self._action()
            except Exception:
                logger.exception("daily report failed")
            completed += 1