import time
import pytest

from ttl_lru_cache import TTLCache, CacheMiss


def test_basic_get_set():
    c = TTLCache(2)
    c.set("a", 1)
    c.set("b", 2)
    assert c.get("a") == 1
    assert c.get("z", 9) == 9
    assert "a" in c


def test_lru_eviction():
    c = TTLCache(2)
    c.set("a", 1)
    c.set("b", 2)
    c.get("a")  # make a recently used
    c.set("c", 3)
    assert "b" not in c
    assert c.get("a") == 1
    assert c.get("c") == 3


def test_ttl_expiry():
    clock = [0.0]
    c = TTLCache(10, default_ttl=5, clock=lambda: clock[0])
    c.set("a", 1)
    assert c.get("a") == 1
    clock[0] = 6
    assert c.get("a") is None
    assert "a" not in c
    assert len(c) == 0


def test_per_entry_ttl_override():
    clock = [0.0]
    c = TTLCache(10, default_ttl=100, clock=lambda: clock[0])
    c.set("short", 1, ttl=2)
    c.set("long", 2)
    clock[0] = 3
    assert "short" not in c
    assert c.get("long") == 2


def test_peek_does_not_update_recency():
    c = TTLCache(2)
    c.set("a", 1)
    c.set("b", 2)
    c.peek("a")
    c.set("c", 3)
    # a was not touched via get, so it should be evicted (b was more recent? actually b inserted last)
    # After set a,b: order a,b. peek a no change. set c evicts LRU = a.
    assert "a" not in c


def test_get_strict_raises():
    c = TTLCache(2)
    with pytest.raises(CacheMiss):
        c.get_strict("nope")


def test_invalid_args():
    with pytest.raises(ValueError):
        TTLCache(0)
    with pytest.raises(ValueError):
        TTLCache(2, default_ttl=0)
    c = TTLCache(2)
    with pytest.raises(ValueError):
        c.set("x", 1, ttl=0)


def test_delete_and_clear():
    c = TTLCache(2)
    c.set("a", 1)
    assert c.delete("a") is True
    assert c.delete("a") is False
    c.set("b", 2)
    c.clear()
    assert len(c) == 0


def test_capacity_eviction_with_expired():
    clock = [0.0]
    c = TTLCache(2, clock=lambda: clock[0])
    c.set("a", 1, ttl=1)
    c.set("b", 2, ttl=1)
    clock[0] = 2  # both expired
    c.set("c", 3)  # should not count expired toward capacity
    assert len(c) == 1
    assert c.get("c") == 3