"""Smoke tests for the reusable scraper building blocks in :mod:`app.scraper.base`.

The generic paginator is exercised end-to-end by the WeChat friend-scraper
tests (it is the only caller today). Here we only sanity-check the
:class:`RateLimiter`'s spacing behaviour so the helper is not shipped blind.
"""

from __future__ import annotations

import asyncio
import time

from app.scraper.base import RateLimiter


async def test_rate_limiter_no_interval_never_waits():
    """``min_interval=0`` is a passthrough — acquire returns immediately."""
    limiter = RateLimiter(min_interval=0.0)
    start = time.monotonic()
    for _ in range(5):
        await limiter.acquire()
    elapsed = time.monotonic() - start
    # 5 acquires with no spacing should complete well under a real interval.
    assert elapsed < 0.1


async def test_rate_limiter_enforces_min_interval():
    """Two acquires are spaced by at least ``min_interval`` seconds."""
    limiter = RateLimiter(min_interval=0.05)
    await limiter.acquire()  # first call never waits; primes ``_last``
    start = time.monotonic()
    await limiter.acquire()  # must wait >= 0.05s since the prior call
    elapsed = time.monotonic() - start
    assert elapsed >= 0.04  # allow a small scheduler slack margin


async def test_rate_limiter_concurrent_acquire_is_safe():
    """Concurrent acquires do not raise; each just waits its turn."""
    limiter = RateLimiter(min_interval=0.01)
    await asyncio.gather(*(limiter.acquire() for _ in range(8)))
    # No assertion on timing here — the contract is "no crash, polite spacing".
    # We only assert the gather completed without raising.


def test_rate_limiter_is_instantiable_with_negative_interval():
    """Negative intervals collapse to the passthrough branch (no surprising raise)."""
    limiter = RateLimiter(min_interval=-1.0)
    assert limiter._min_interval <= 0  # sanity check the guard