package node

import (
	"bytes"
	"crypto/rand"
	"reflect"
	"testing"

	"golang.org/x/crypto/nacl/box"
)

func TestEncryptDecryptAsym(t *testing.T) {
	pubKey1, privKey1, err := box.GenerateKey(rand.Reader)
	if err != nil {
		t.Fatal(err)
	}

	pubKey2, privKey2, err := box.GenerateKey(rand.Reader)
	if err != nil {
		t.Fatal(err)
	}

	sharedEncKey := [32]byte{}
	box.Precompute(&sharedEncKey, pubKey2, privKey1)

	sharedDecKey := [32]byte{}
	box.Precompute(&sharedDecKey, pubKey1, privKey2)

	original := make([]byte, if_mtu-64)
	rand.Read(original)

	h := header{
		Counter:  2893749238,
		SourceIP: 5,
		DestIP:   12,
		Forward:  1,
		Stream:   1,
	}

	encrypted := make([]byte, bufferSize)
	encrypted = encryptPacketAsym(&h, sharedEncKey[:], original, encrypted)

	decrypted := make([]byte, bufferSize)
	var ok bool
	decrypted, ok = decryptPacketAsym(sharedDecKey[:], encrypted, decrypted)
	if !ok {
		t.Fatal(ok)
	}

	var h2 header
	h2.Parse(encrypted)

	if !reflect.DeepEqual(h, h2) {
		t.Fatal(h, h2)
	}

	if !bytes.Equal(original, decrypted) {
		t.Fatal("mismatch")
	}
}

func BenchmarkEncryptAsym(b *testing.B) {
	_, privKey1, err := box.GenerateKey(rand.Reader)
	if err != nil {
		b.Fatal(err)
	}

	pubKey2, _, err := box.GenerateKey(rand.Reader)
	if err != nil {
		b.Fatal(err)
	}

	sharedEncKey := [32]byte{}
	box.Precompute(&sharedEncKey, pubKey2, privKey1)

	original := make([]byte, if_mtu)
	rand.Read(original)

	nonce := make([]byte, headerSize)
	rand.Read(nonce)

	encrypted := make([]byte, bufferSize)

	h := header{
		Counter:  2893749238,
		SourceIP: 5,
		DestIP:   12,
		Forward:  1,
		Stream:   1,
	}

	for i := 0; i < b.N; i++ {
		encrypted = encryptPacketAsym(&h, sharedEncKey[:], original, encrypted)
	}
}

func BenchmarkDecryptAsym(b *testing.B) {
	pubKey1, privKey1, err := box.GenerateKey(rand.Reader)
	if err != nil {
		b.Fatal(err)
	}

	pubKey2, privKey2, err := box.GenerateKey(rand.Reader)
	if err != nil {
		b.Fatal(err)
	}

	sharedEncKey := [32]byte{}
	box.Precompute(&sharedEncKey, pubKey2, privKey1)

	sharedDecKey := [32]byte{}
	box.Precompute(&sharedDecKey, pubKey1, privKey2)

	original := make([]byte, if_mtu)
	rand.Read(original)

	nonce := make([]byte, headerSize)
	rand.Read(nonce)

	h := header{
		Counter:  2893749238,
		SourceIP: 5,
		DestIP:   12,
		Forward:  1,
		Stream:   1,
	}

	encrypted := encryptPacketAsym(&h, sharedEncKey[:], original, make([]byte, bufferSize))
	decrypted := make([]byte, bufferSize)
	var ok bool
	for i := 0; i < b.N; i++ {
		decrypted, ok = decryptPacketAsym(sharedDecKey[:], encrypted, decrypted)
		if !ok {
			panic(ok)
		}
	}
}