"""Tests for the bounded TTL cache utility."""

from __future__ import annotations

import time

import pytest

from aegis_gitea_mcp.cache import BoundedTTLCache


def test_set_and_get_returns_value() -> None:
    """A stored value is returned before it expires."""
    cache: BoundedTTLCache[str, int] = BoundedTTLCache(ttl_seconds=60, max_size=8)
    cache.set("a", 1)
    assert cache.get("a") == 1


def test_missing_key_returns_none() -> None:
    """An unknown key returns None."""
    cache: BoundedTTLCache[str, int] = BoundedTTLCache(ttl_seconds=60)
    assert cache.get("missing") is None


def test_entry_expires_after_ttl() -> None:
    """An entry is evicted once its TTL elapses."""
    cache: BoundedTTLCache[str, int] = BoundedTTLCache(ttl_seconds=0.05, max_size=8)
    cache.set("a", 1)
    assert cache.get("a") == 1
    time.sleep(0.06)
    assert cache.get("a") is None


def test_size_bound_evicts_oldest() -> None:
    """The cache never exceeds max_size; oldest entries are evicted first."""
    cache: BoundedTTLCache[int, int] = BoundedTTLCache(ttl_seconds=60, max_size=3)
    for i in range(5):
        cache.set(i, i)
    assert len(cache) == 3
    # 0 and 1 were evicted; 2, 3, 4 remain.
    assert cache.get(0) is None
    assert cache.get(1) is None
    assert cache.get(4) == 4


def test_reinsert_refreshes_recency() -> None:
    """Re-setting a key refreshes its position so it is not evicted first."""
    cache: BoundedTTLCache[str, int] = BoundedTTLCache(ttl_seconds=60, max_size=2)
    cache.set("a", 1)
    cache.set("b", 2)
    cache.set("a", 3)  # refresh "a"
    cache.set("c", 4)  # should evict "b", the oldest
    assert cache.get("b") is None
    assert cache.get("a") == 3
    assert cache.get("c") == 4


def test_clear_empties_cache() -> None:
    """clear() removes all entries."""
    cache: BoundedTTLCache[str, int] = BoundedTTLCache(ttl_seconds=60)
    cache.set("a", 1)
    cache.clear()
    assert cache.get("a") is None
    assert len(cache) == 0


def test_invalid_constructor_args() -> None:
    """Non-positive TTL or size is rejected."""
    with pytest.raises(ValueError):
        BoundedTTLCache(ttl_seconds=0)
    with pytest.raises(ValueError):
        BoundedTTLCache(ttl_seconds=60, max_size=0)