package crypto

import (
	"encoding/hex"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/stretchr/testify/require"
	"testing"
)

func TestExtractSignatures(t *testing.T) {
	const content1 = "045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b04ca82dd41fa592bf46ecf7e2eddae61013fc95a565b59c49f37f06b1b591ed3bd24e143495f2d1e241e151ab3572ac108d577be349d4b88d3d5a50c481ab35441"
	const content2 = "045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b04ca82dd41fa592bf46ecf7e2eddae61013fc95a565b59c49f37f06b1b591ed3bd24e143495f2d1e241e151ab3572ac108d577be349d4b88d3d5a50c481ab35440"

	key1, err := crypto.GenerateKey()
	require.NoError(t, err)

	key2, err := crypto.GenerateKey()
	require.NoError(t, err)

	signature1, err := Sign(content1, key1)
	require.NoError(t, err)

	signature2, err := Sign(content2, key2)
	require.NoError(t, err)

	key1String := hex.EncodeToString(crypto.FromECDSAPub(&key1.PublicKey))
	key2String := hex.EncodeToString(crypto.FromECDSAPub(&key2.PublicKey))

	pair1 := [2]string{content1, signature1}
	pair2 := [2]string{content2, signature2}

	signaturePairs := [][2]string{pair1, pair2}

	extractedSignatures, err := ExtractSignatures(signaturePairs)
	require.NoError(t, err)
	require.Equal(t, []string{key1String, key2String}, extractedSignatures)

	// Test wrong content
	pair3 := [2]string{content1, signature2}

	signaturePairs = [][2]string{pair1, pair2, pair3}

	extractedSignatures, err = ExtractSignatures(signaturePairs)
	require.NoError(t, err)
	// The public key is neither the one which generated the content, nor the one generated the signature
	require.NotEqual(t, []string{key1String, key2String, key1String}, extractedSignatures)
	require.NotEqual(t, []string{key1String, key2String, key2String}, extractedSignatures)
}

func TestVerifySignature(t *testing.T) {
	const content1 = "045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b04ca82dd41fa592bf46ecf7e2eddae61013fc95a565b59c49f37f06b1b591ed3bd24e143495f2d1e241e151ab3572ac108d577be349d4b88d3d5a50c481ab35441"
	const content2 = "045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b045a8cae84d8d139e887bb927d2b98cee481afae3770e0ee45f2dc19c6545e45921bc6a55ea92b705e45dfbbe47182c7b1d64a080a220d2781577163923d7cbb4b04ca82dd41fa592bf46ecf7e2eddae61013fc95a565b59c49f37f06b1b591ed3bd24e143495f2d1e241e151ab3572ac108d577be349d4b88d3d5a50c481ab35440"

	key1, err := crypto.GenerateKey()
	require.NoError(t, err)

	key2, err := crypto.GenerateKey()
	require.NoError(t, err)

	signature1, err := Sign(content1, key1)
	require.NoError(t, err)

	signature2, err := Sign(content2, key2)
	require.NoError(t, err)

	key1String := hex.EncodeToString(crypto.FromECDSAPub(&key1.PublicKey))
	key2String := hex.EncodeToString(crypto.FromECDSAPub(&key2.PublicKey))

	pair1 := [3]string{content1, signature1, key1String}
	pair2 := [3]string{content2, signature2, key2String}

	signaturePairs := [][3]string{pair1, pair2}

	err = VerifySignatures(signaturePairs)
	require.NoError(t, err)

	// Test wrong content
	pair3 := [3]string{content1, signature2, key2String}

	signaturePairs = [][3]string{pair1, pair2, pair3}

	err = VerifySignatures(signaturePairs)
	require.Error(t, err)

	// Test wrong signature
	pair3 = [3]string{content1, signature2, key1String}

	signaturePairs = [][3]string{pair1, pair2, pair3}

	err = VerifySignatures(signaturePairs)
	require.Error(t, err)

	// Test wrong pubkey
	pair3 = [3]string{content1, signature1, key2String}

	signaturePairs = [][3]string{pair1, pair2, pair3}

	err = VerifySignatures(signaturePairs)
	require.Error(t, err)
}

func TestSymmetricEncryption(t *testing.T) {
	const rawKey = "0000000000000000000000000000000000000000000000000000000000000000"
	expectedPlaintext := []byte("test")
	key, err := hex.DecodeString(rawKey)
	require.Nil(t, err, "Key should be generated without errors")

	cyphertext1, err := EncryptSymmetric(key, expectedPlaintext)
	require.Nil(t, err, "Cyphertext should be generated without errors")

	cyphertext2, err := EncryptSymmetric(key, expectedPlaintext)
	require.Nil(t, err, "Cyphertext should be generated without errors")

	require.Equalf(
		t,
		32,
		len(cyphertext1),
		"Cyphertext with the correct length should be generated")

	require.NotEqualf(
		t,
		cyphertext1,
		cyphertext2,
		"Same plaintext should not be encrypted in the same way")

	plaintext, err := DecryptSymmetric(key, cyphertext1)
	require.Nil(t, err, "Cyphertext should be decrypted without errors")

	require.Equalf(
		t,
		expectedPlaintext,
		plaintext,
		"Cypther text should be decrypted successfully")
}