import threading
import time
import unittest

from lru_ttl_cache import LRUTTLCache


class TestLRUTTLCache(unittest.TestCase):
    def test_basic_put_get(self):
        c = LRUTTLCache(maxsize=2, ttl=10)
        c.put("a", 1)
        self.assertEqual(c.get("a"), 1)
        self.assertEqual(c.get("missing", "d"), "d")

    def test_lru_eviction(self):
        c = LRUTTLCache(maxsize=2, ttl=10)
        c.put("a", 1); c.put("b", 2)
        c.get("a")  # refresh a
        c.put("c", 3)  # evicts b
        self.assertEqual(c.get("b", None), None)
        self.assertEqual(c.get("a"), 1)
        self.assertEqual(c.get("c"), 3)

    def test_ttl_expiry(self):
        clock = {"t": 0.0}
        c = LRUTTLCache(maxsize=4, ttl=5, clock=lambda: clock["t"])
        c.put("a", 1)
        self.assertTrue(c.contains("a"))
        clock["t"] = 6.0
        self.assertFalse(c.contains("a"))
        self.assertEqual(c.get("a", "x"), "x")

    def test_put_overwrite_resets_ttl(self):
        clock = {"t": 0.0}
        c = LRUTTLCache(maxsize=4, ttl=5, clock=lambda: clock["t"])
        c.put("a", 1)
        clock["t"] = 4.0
        c.put("a", 2)  # reset ttl: now expires at 9
        clock["t"] = 8.0
        self.assertEqual(c.get("a"), 2)
        clock["t"] = 10.0
        self.assertEqual(c.get("a", "x"), "x")

    def test_stats(self):
        c = LRUTTLCache(maxsize=2, ttl=10)
        c.put("a", 1); c.put("b", 2)
        c.get("a"); c.get("zzz")
        s = c.stats
        self.assertEqual(s["hits"], 1)
        self.assertEqual(s["misses"], 1)
        self.assertEqual(s["size"], 2)

    def test_thread_safety(self):
        c = LRUTTLCache(maxsize=100, ttl=100)
        errs = []

        def w(i):
            try:
                for j in range(50):
                    c.put((i, j), i * j)
                    c.get((i, j))
            except Exception as e:  # noqa
                errs.append(e)

        ts = [threading.Thread(target=w, args=(i,)) for i in range(8)]
        for t in ts: t.start()
        for t in ts: t.join()
        self.assertFalse(errs)

    def test_validation(self):
        with self.assertRaises(ValueError):
            LRUTTLCache(maxsize=0, ttl=1)
        with self.assertRaises(ValueError):
            LRUTTLCache(maxsize=1, ttl=0)


if __name__ == "__main__":
    unittest.main()