package dataext

import (
	"sync"
	"sync/atomic"
	"testing"
)

func TestMutexSet_BasicLockUnlock(t *testing.T) {
	ms := NewMutexSet[string]()
	ms.Lock("a")
	ms.Unlock("a")
	ms.RLock("b")
	ms.RUnlock("b")
}

func TestMutexSet_DifferentKeysIndependent(t *testing.T) {
	ms := NewMutexSet[int]()
	ms.Lock(1)
	ms.Lock(2)
	ms.Unlock(1)
	ms.Unlock(2)
}

func TestMutexSet_SameKeyMutuallyExclusive(t *testing.T) {
	ms := NewMutexSet[string]()
	var counter int64
	const n = 50
	var wg sync.WaitGroup
	wg.Add(n)
	for i := 0; i < n; i++ {
		go func() {
			defer wg.Done()
			ms.Lock("shared")
			atomic.AddInt64(&counter, 1)
			ms.Unlock("shared")
		}()
	}
	wg.Wait()
	if atomic.LoadInt64(&counter) != n {
		t.Fatalf("got %d want %d", counter, n)
	}
}

func TestMutexSet_RLockMultiple(t *testing.T) {
	ms := NewMutexSet[string]()
	ms.RLock("k")
	ms.RLock("k")
	ms.RUnlock("k")
	ms.RUnlock("k")
}