package wallet_sdk

import (
	"crypto/rand"
	"encoding/hex"
	"encoding/pem"
	"fmt"
	hds "git.yuanzoo.cn/zhangzhengqiang/popi-zxl/third_party/official/gosdk_demo/zxsdk/wallet_sdk/hdsignature"
	"git.yuanzoo.cn/zhangzhengqiang/popi-zxl/third_party/official/gosdk_demo/zxsdk/wallet_sdk/mnemonics"
	"math/big"
	"strconv"
	"time"
)

const (
	defaultEntropy = 128
)

var (
	defaultIndexPathPrefix = []uint32{66, 0, 0, 0}
)

// Mnemonics

func CreateMnemonic() (string, error) {
	entropy, err := mnemonics.NewEntropy(defaultEntropy)
	if err != nil {
		return "", err
	}
	return mnemonics.NewMnemonic(entropy)
}

// HD Signature

// DeriveKeyPair derives key pair strings for the node m/66/0/0/0/index
func DeriveKeyPair(mnemonic string, index uint32) (string, string, error) {
	return DeriveKeyPairEncrypted(mnemonic, index, nil)
}

func DeriveKeyPairEncrypted(mnemonic string, index uint32, password []byte) (string, string, error) {
	msk, _, err := hds.CreateMasterKey(mnemonic)
	if err != nil {
		return "", "", err
	}

	psk, err := msk.DeriveKeyPairObjFromFullPath(defaultIndexPathPrefix)
	if err != nil {
		return "", "", err
	}

	sk, err := psk.DeriveChildPrivateKey(index)
	if err != nil {
		return "", "", err
	}

	skPEM, err := sk.GetPrunedPEM(password)
	if err != nil {
		return "", "", err
	}

	pkPEM, err := sk.GetPublicKey().GetPrunedPEM()
	if err != nil {
		return "", "", err
	}

	return skPEM, pkPEM, nil
}

// DeriveKeyPairFullPath derives key pair strings for the node m/path[0]/...
func DeriveKeyPairFullPath(mnemonic string, path []uint32) (string, string, error) {
	return DeriveKeyPairFullPathEncrypted(mnemonic, path, nil)
}
func DeriveKeyPairFullPathEncrypted(mnemonic string, path []uint32, password []byte) (string, string, error) {
	msk, _, err := hds.CreateMasterKey(mnemonic)
	if err != nil {
		return "", "", err
	}

	sk, err := msk.DeriveKeyPairObjFromFullPath(path)
	if err != nil {
		return "", "", err
	}

	skPEM, err := sk.GetPrunedPEM(password)
	if err != nil {
		return "", "", err
	}

	pkPEM, err := sk.GetPublicKey().GetPrunedPEM()
	if err != nil {
		return "", "", err
	}

	return skPEM, pkPEM, nil
}

func PriKey2PubKey(pri string) (string, error) {
	return EncryptedPriKey2PubKey(pri, nil)
}

func EncryptedPriKey2PubKey(pri string, password []byte) (string, error) {
	sk, err := hds.ParsePrivateKey([]byte(pri), password)
	if err != nil {
		return "", err
	}

	return sk.GetPublicKey().GetPrunedPEM()
}

func PubKey2Address(pubKey string) (string, error) {
	pk, err := hds.ParsePublicKey([]byte(pubKey))
	if err != nil {
		return "", err
	}

	return pk.GetAddress()
}

func PriKey2Address(priKey string) (string, error) {
	return EncryptedPriKey2Address(priKey, nil)
}

func EncryptedPriKey2Address(priKey string, password []byte) (string, error) {
	sk, err := hds.ParsePrivateKey([]byte(priKey), password)
	if err != nil {
		return "", err
	}

	return sk.GetAddress()
}

func SignByPriKey(priKey string, data string) (string, error) {
	return SignByEncryptedPriKey(priKey, data, nil)
}

func SignByEncryptedPriKey(priKey string, data string, password []byte) (string, error) {
	sk, err := hds.ParsePrivateKey([]byte(priKey), password)
	if err != nil {
		return "", err
	}

	sig, err := sk.Sign(data)
	if err != nil {
		return "", err
	}
	sigHex := hex.EncodeToString(sig)
	return sigHex, nil
}

func VerifyByPubKey(pubKey string, signedData string, data string) (bool, error) {
	pk, err := hds.ParsePublicKey([]byte(pubKey))
	if err != nil {
		return false, err
	}

	sig, err := hex.DecodeString(signedData)
	if err != nil {
		return false, err
	}
	return pk.Verify(data, sig)
}

func GetBase64PrivateKey(priKey string) (string, error) {
	return GetBase64EncryptedPrivateKey(priKey, nil)
}

func GetBase64EncryptedPrivateKey(priKey string, password []byte) (string, error) {
	sk, err := hds.ParsePrivateKey([]byte(priKey), password)
	if err != nil {
		return "", err
	}
	return sk.GetBase64String(password)
}

func GetBase64PublicKey(pubKey string) (string, error) {
	pk, err := hds.ParsePublicKey([]byte(pubKey))
	if err != nil {
		return "", err
	}
	return pk.GetBase64String()
}

// Certificate with SM2 public key

// Create certificate request (csr)
func CreateCSR(priKey string, templateStr string) (string, error) {
	return CreateCSRFromEncryptedPrivateKey(priKey, templateStr, nil)
}

func CreateCSRFromEncryptedPrivateKey(priKey string, templateStr string, password []byte) (string, error) {
	sk, err := hds.ParsePrivateKey([]byte(priKey), password)
	if err != nil {
		return "", err
	}

	csr, err := sk.CreateCSRFromTemplatePEM(templateStr)
	if err != nil {
		return "", err
	}

	return string(csr), nil
}

func CheckSignatureValidity(sig string) (bool, error) {
	sigBytes, err := hex.DecodeString(sig)
	if err != nil {
		return false, err
	}

	if len(sigBytes) < hds.SigMinLength || len(sigBytes) > hds.SigMaxLength {
		return false, fmt.Errorf("invalid signature length (%d)", len(sig))
	}

	return true, nil
}

func CheckPublicKeyValidity(pubKey string) (bool, error) {
	pubKeyBlock, _ := pem.Decode([]byte(pubKey))
	if pubKeyBlock == nil {
		return false, fmt.Errorf("invalid public key encoding")
	}

	if len(pubKeyBlock.Bytes) < hds.PubKeyMinLength || len(pubKeyBlock.Bytes) > hds.PubKeyMaxLength {
		return false, fmt.Errorf("invalid public key length (%d)", len(pubKeyBlock.Bytes))
	}

	return true, nil
}

func CheckAddressValidity(address string) (bool, error) {
	addressBytes := []byte(address)
	prefix := string(addressBytes[:2])
	pkHash := addressBytes[2:]

	if len(pkHash) != hds.HDWAddressLength*2 {
		return false, fmt.Errorf("hash part should be %d bytes", hds.HDWAddressLength*2)
	}

	_, err := hex.DecodeString(string(pkHash))
	if err != nil {
		return false, err
	}

	switch prefix {
	case hds.ZXAddrPrefix, hds.ZXAddrPrefixV1, hds.ZXAddrPrefixV2, hds.ZXAddrPrefixV3:
		return true, nil
	default:
		return false, fmt.Errorf("invalid prefix")
	}
}

type SignData struct {
	Signature     string
	SignatureTime string
	Nonce         int
}

const (
	MaxRandNum = 1000000
	MinRandNum = 100000
)

func GenerateApiSign(appId, appKey string) (signData *SignData, err error) {
	now := time.Now()
	signTime := strconv.FormatInt(now.UnixNano()/1e6, 10)
	nonce, err := generateNonce()
	if err != nil {
		return nil, err
	}
	signData = &SignData{}

	signStr := ""
	if appId != "" && appKey != "" {
		signStr = appId + "&" + appKey + "&" + signTime + "&" + strconv.Itoa(nonce)
	} else {
		signStr = signTime + "&" + strconv.Itoa(nonce)
	}

	sign, err := hds.SM3HMAC([]byte(appKey), []byte(signStr))
	if err != nil {
		return nil, err
	}
	signData.Signature = hex.EncodeToString(sign)
	signData.SignatureTime = signTime
	signData.Nonce = nonce
	return signData, nil
}

func generateNonce() (int, error) {
	b := new(big.Int).SetInt64(MaxRandNum)
	randNum, err := rand.Int(rand.Reader, b)
	if err != nil {
		return -1, err
	}
	nonce := int(randNum.Int64())
	if nonce < MinRandNum {
		nonce = nonce + MinRandNum
	}
	return nonce, nil
}