package vhost

import (
	"testing"
	"unsafe"

	"github.com/stretchr/testify/assert"
)

func TestMemoryRegion_Size(t *testing.T) {
	assert.EqualValues(t, 32, unsafe.Sizeof(MemoryRegion{}))
}

func TestMemoryLayout_SerializePayload(t *testing.T) {
	layout := MemoryLayout([]MemoryRegion{
		{
			GuestPhysicalAddress: 42,
			Size:                 100,
			UserspaceAddress:     142,
		}, {
			GuestPhysicalAddress: 99,
			Size:                 100,
			UserspaceAddress:     99,
		},
	})
	payload := layout.serializePayload()

	assert.Equal(t, []byte{
		0x02, 0x00, 0x00, 0x00, // nregions
		0x00, 0x00, 0x00, 0x00, // padding
		// region 0
		0x2a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // guest_phys_addr
		0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // memory_size
		0x8e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // userspace_addr
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // flags_padding
		// region 1
		0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // guest_phys_addr
		0x64, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // memory_size
		0x63, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // userspace_addr
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // flags_padding
	}, payload)
}