package vm

import (
	"testing"

	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
	"github.com/stretchr/testify/require"
)

func TestRefCounter_Add(t *testing.T) {
	r := newRefCounter()

	require.Equal(t, 0, int(*r))

	r.Add(stackitem.Null{})
	require.Equal(t, 1, int(*r))

	r.Add(stackitem.Null{})
	require.Equal(t, 2, int(*r)) // count scalar items twice

	arr := stackitem.NewArray([]stackitem.Item{stackitem.NewByteArray([]byte{1}), stackitem.NewBool(false)})
	r.Add(arr)
	require.Equal(t, 5, int(*r)) // array + 2 elements

	r.Add(arr)
	require.Equal(t, 6, int(*r)) // count only array

	r.Remove(arr)
	require.Equal(t, 5, int(*r))

	r.Remove(arr)
	require.Equal(t, 2, int(*r))

	m := stackitem.NewMap()
	m.Add(stackitem.NewByteArray([]byte("some")), stackitem.NewBool(false))
	r.Add(m)
	require.Equal(t, 5, int(*r)) // map + key + value

	r.Add(m)
	require.Equal(t, 6, int(*r)) // map only

	r.Remove(m)
	require.Equal(t, 5, int(*r))

	r.Remove(m)
	require.Equal(t, 2, int(*r))
}

func TestRefCounterPopItem(t *testing.T) {
	prog := makeProgram(opcode.POPITEM)
	v := load(prog)
	v.estack.PushVal(stackitem.NewArray([]stackitem.Item{stackitem.Make(42)}))
	require.Equal(t, 2, int(v.refs))
	runVM(t, v)
	require.Equal(t, 1, v.estack.Len())
	require.Equal(t, 1, int(v.refs))
	_ = v.estack.Pop()
	require.Equal(t, 0, v.estack.Len())
	require.Equal(t, 0, int(v.refs))
}

func BenchmarkRefCounter_Add(b *testing.B) {
	a := stackitem.NewArray(nil)
	rc := newRefCounter()

	b.ResetTimer()
	for range b.N {
		rc.Add(a)
	}
}

func BenchmarkRefCounter_AddRemove(b *testing.B) {
	a := stackitem.NewArray([]stackitem.Item{})
	rc := newRefCounter()

	b.ResetTimer()
	for range b.N {
		rc.Add(a)
		rc.Remove(a)
	}
}