package bridge

import (
	"fmt"
	"testing"
)

func TestBoundedUUIDSet_AddAndContains(t *testing.T) {
	s := NewBoundedUUIDSet(10)
	if s.Contains("a") {
		t.Error("empty set should not contain 'a'")
	}
	if !s.Add("a") {
		t.Error("first Add should return true (new)")
	}
	if s.Add("a") {
		t.Error("second Add should return false (duplicate)")
	}
	if !s.Contains("a") {
		t.Error("should contain 'a' after Add")
	}
}

func TestBoundedUUIDSet_Eviction(t *testing.T) {
	cap := 5
	s := NewBoundedUUIDSet(cap)

	// 填满
	for i := 0; i < cap; i++ {
		s.Add(fmt.Sprintf("id-%d", i))
	}
	if s.Len() != cap {
		t.Errorf("expected len=%d, got %d", cap, s.Len())
	}

	// 超出容量,最老的 id-0 应该被淘汰
	s.Add("id-new")
	if s.Len() != cap {
		t.Errorf("len should stay at cap=%d after eviction, got %d", cap, s.Len())
	}
	if s.Contains("id-0") {
		t.Error("id-0 should have been evicted")
	}
	if !s.Contains("id-new") {
		t.Error("id-new should be in set")
	}
}

func TestBoundedUUIDSet_FIFO_Eviction_Order(t *testing.T) {
	s := NewBoundedUUIDSet(3)
	s.Add("a")
	s.Add("b")
	s.Add("c") // 满了

	s.Add("d") // 淘汰 a
	if s.Contains("a") {
		t.Error("a should be evicted first (FIFO)")
	}
	if !s.Contains("b") {
		t.Error("b should still be present")
	}
	if !s.Contains("c") {
		t.Error("c should still be present")
	}
	if !s.Contains("d") {
		t.Error("d should be present")
	}
}

func TestBoundedUUIDSet_MultipleEvictions(t *testing.T) {
	s := NewBoundedUUIDSet(3)
	for i := 0; i < 10; i++ {
		id := fmt.Sprintf("id-%d", i)
		s.Add(id)
	}
	// 只有最后 3 个应该存在:id-7, id-8, id-9
	for i := 0; i < 7; i++ {
		if s.Contains(fmt.Sprintf("id-%d", i)) {
			t.Errorf("id-%d should have been evicted", i)
		}
	}
	for i := 7; i < 10; i++ {
		if !s.Contains(fmt.Sprintf("id-%d", i)) {
			t.Errorf("id-%d should be present", i)
		}
	}
}

func TestBoundedUUIDSet_DefaultCap(t *testing.T) {
	s := NewBoundedUUIDSet(0) // 0 → 默认 1000
	if s.Cap() != 1000 {
		t.Errorf("default cap should be 1000, got %d", s.Cap())
	}
}

func TestBoundedUUIDSet_ConcurrentAdd(t *testing.T) {
	s := NewBoundedUUIDSet(100)
	done := make(chan struct{})
	for g := 0; g < 10; g++ {
		g := g
		go func() {
			for i := 0; i < 20; i++ {
				s.Add(fmt.Sprintf("g%d-id%d", g, i))
			}
			done <- struct{}{}
		}()
	}
	for i := 0; i < 10; i++ {
		<-done
	}
	// 100 个唯一 ID 填满 cap=100,不应 panic 或数据竞争
	if s.Len() != 100 {
		t.Errorf("expected len=100, got %d", s.Len())
	}
}