package orbyte

import (
	"crypto/rand"
	"runtime"
	"sync"
	"testing"
)

func TestPool(t *testing.T) {
	p := NewPool[[]byte](simplepooler{})
	x := p.New(200)
	x.Destroy()
	out, in := p.CountItems()
	t.Log("out", out, "in", in)
	if out != 0 || in != 1 {
		t.Fatal("unexpected behavior")
	}
	for i := 0; i < 2000; i++ {
		item := p.New(i)
		out, in = p.CountItems()
		if out != 1 || in != 0 {
			t.Fatal("unexpected behavior")
		}
		item.Destroy()
	}
	out, in = p.CountItems()
	t.Log("out", out, "in", in)
	if out != 0 {
		t.Fatal("unexpected behavior")
	}
	wg := sync.WaitGroup{}
	for i := 0; i < 4096; i++ {
		item := p.New(i)
		for j := 0; j < 16; j++ {
			wg.Add(1)
			user(item.Ref(), &wg)
			wg.Add(1)
			go usernodestroy(item.Copy(), &wg)
		}
		wg.Add(1)
		go usernodestroy(item.Trans(), &wg)
	}
	wg.Wait()
	runtime.GC()
	out, in = p.CountItems()
	t.Log("out", out, "in", in)
	if out != 0 {
		t.Fatal("unexpected behavior")
	}
}

func user(item *Item[[]byte], wg *sync.WaitGroup) {
	defer wg.Done()
	rand.Read(item.Unwrap())
	item.Destroy()
}

func usernodestroy(item *Item[[]byte], wg *sync.WaitGroup) {
	defer wg.Done()
	rand.Read(item.Unwrap())
}

type simplepooler struct{}

func (simplepooler) New(config any, pooled []byte) []byte {
	if cap(pooled) >= config.(int) {
		return pooled[:config.(int)]
	}
	return make([]byte, config.(int))
}

func (simplepooler) Parse(obj any, pooled []byte) []byte {
	src := obj.([]byte)
	if cap(pooled) >= len(src) {
		copy(pooled[:len(src)], src)
		return pooled[:len(src)]
	}
	return obj.([]byte)
}

func (simplepooler) Reset(item *[]byte) {
	*item = (*item)[:0]
}

func (simplepooler) Copy(dst, src *[]byte) {
	copy(*dst, *src)
}