package cache

import (
	"testing"
	"time"
)

func TestGetPut(t *testing.T) {
	c := New[string, int](2, time.Minute)
	if _, ok := c.Get("a"); ok {
		t.Fatal("empty cache returned a hit")
	}
	c.Put("a", 1)
	got, ok := c.Get("a")
	if !ok || got != 1 {
		t.Fatalf("get after put: ok=%v val=%v", ok, got)
	}
}

func TestTTL(t *testing.T) {
	c := New[string, int](8, 10*time.Millisecond)
	c.Put("a", 1)
	if _, ok := c.Get("a"); !ok {
		t.Fatal("fresh entry missing")
	}
	time.Sleep(20 * time.Millisecond)
	if _, ok := c.Get("a"); ok {
		t.Fatal("expired entry still served")
	}
}

func TestLRUEviction(t *testing.T) {
	c := New[string, int](2, time.Minute)
	c.Put("a", 1)
	c.Put("b", 2)
	_, _ = c.Get("a") // make "a" most-recently-used so "b" is the eviction victim
	c.Put("c", 3)     // exceeds cap → evict LRU ("b")
	if _, ok := c.Get("b"); ok {
		t.Fatal("LRU victim 'b' not evicted")
	}
	if _, ok := c.Get("a"); !ok {
		t.Fatal("recently-used 'a' was evicted")
	}
	if _, ok := c.Get("c"); !ok {
		t.Fatal("freshly-put 'c' missing")
	}
}