"""Tests for the TTL async cache + Airtable cache wiring."""

from __future__ import annotations

import asyncio

import pytest

from app.services.cache import TTLAsyncCache


@pytest.mark.asyncio
async def test_second_call_hits_cache():
    cache = TTLAsyncCache(ttl=60)
    counter = {"n": 0}

    async def loader():
        counter["n"] += 1
        return {"v": counter["n"]}

    a = await cache.get_or_set("k", loader)
    b = await cache.get_or_set("k", loader)
    assert a == b == {"v": 1}
    assert counter["n"] == 1


@pytest.mark.asyncio
async def test_invalidate_forces_reload():
    cache = TTLAsyncCache(ttl=60)
    counter = {"n": 0}

    async def loader():
        counter["n"] += 1
        return counter["n"]

    assert await cache.get_or_set("k", loader) == 1
    cache.invalidate("k")
    assert await cache.get_or_set("k", loader) == 2


@pytest.mark.asyncio
async def test_lock_prevents_thundering_herd():
    cache = TTLAsyncCache(ttl=60)
    counter = {"n": 0}

    async def slow_loader():
        # Yield once so other coroutines have a chance to enter.
        counter["n"] += 1
        await asyncio.sleep(0.05)
        return counter["n"]

    results = await asyncio.gather(
        cache.get_or_set("k", slow_loader),
        cache.get_or_set("k", slow_loader),
        cache.get_or_set("k", slow_loader),
        cache.get_or_set("k", slow_loader),
        cache.get_or_set("k", slow_loader),
    )
    # All callers see the same cached value, loader ran only once.
    assert counter["n"] == 1
    assert all(r == 1 for r in results)


@pytest.mark.asyncio
async def test_refresh_bypasses_cache():
    """Simulate the 'refresh=true' behaviour the router uses."""
    cache = TTLAsyncCache(ttl=60)
    counter = {"n": 0}

    async def loader():
        counter["n"] += 1
        return counter["n"]

    await cache.get_or_set("k", loader)
    # Router invalidates, then re-fetches.
    cache.invalidate("k")
    await cache.get_or_set("k", loader)
    assert counter["n"] == 2