package utils

import (
	"bytes"
	"crypto/rand"
	"fmt"
	"io"
	"os"
	"os/exec"
	"time"
)

const (
	OPENSSL_PATH = "openssl"
	// WORK_PATH    = "/opt/arrokoth/ca-mini"
	WORK_PATH = "/Users/seven/arrokoth/sample-demo/certificate-management/ca-server"
	CA_CERT   = WORK_PATH + "/ca/CaRoot.crt"
	CA_CONFIG = WORK_PATH + "/ca/ca.conf"
	CERT_PATH = WORK_PATH + "/cert"
	CRL       = WORK_PATH + "/crl/CaRoot.crl"
)

// GenerateRandomString 生成指定长度的随机字符串
func GenerateRandomString(length int) (string, error) {
	// 创建一个字节切片，用于存储随机数据
	bytes := make([]byte, length)

	// 使用crypto/rand包生成随机字节
	_, err := io.ReadFull(rand.Reader, bytes)
	if err != nil {
		return "", fmt.Errorf("failed to generate random string: %v", err)
	}

	// 将随机字节转换为Base64字符串
	// randomString := base64.RawURLEncoding.EncodeToString(bytes)

	// 将随机字节转换为十六进制字符串
	randomString := fmt.Sprintf("%x", bytes)

	return randomString, nil
}

// 根据时间戳+随机数生成唯一ID
func GenerateUniqueID() (string, error) {
	// 获取当前时间戳
	timestamp := time.Now().UnixNano()

	// 生成随机数
	randomNumber, err := GenerateRandomString(8)
	if err != nil {
		return "", err
	}

	// 拼接时间戳和随机数
	uniqueID := fmt.Sprintf("%d%s", timestamp, randomNumber)

	// uniqueID := fmt.Sprintf("%d%s", timestamp, uuid.New().String())

	return uniqueID, nil
}

func GetKeyFilePath(keyId string) string {
	return CERT_PATH + "/" + keyId + ".key"
}

func GetCsrFilePath(keyId string) string {
	return CERT_PATH + "/" + keyId + ".csr"
}

func GetCertFilePath(subject string) string {
	return CERT_PATH + "/" + subject + ".crt"
}

// 生成密钥
func GenerateKey(alg string, len int) (string, error) {
	// 生成私钥
	// openssl genrsa -out Ca.key 2048
	var keyAlg string
	var keyLen string
	id, err := GenerateUniqueID()
	if err != nil {
		return "", err
	}
	keyFilePath := GetKeyFilePath(id)
	switch alg {
	case "rsa":
		keyAlg = "rsa"
	case "ec":
		keyAlg = "ec"
	default:
		keyAlg = "rsa"
	}

	switch len {
	case 1024:
		keyLen = "1024"
	case 2048:
		keyLen = "2048"
	case 4096:
		keyLen = "4096"
	default:
		keyLen = "2048"
	}
	// 创建命令
	xcmd := exec.Command(OPENSSL_PATH, "gen"+keyAlg, "-out", keyFilePath, keyLen)

	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr

	// 执行命令
	err = xcmd.Run()
	if err != nil {
		return "", fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}

	return id, nil
}

// 生成证书请求
func GenerateCsr(id string, subject string, sans []string) (string, error) {
	// 生成证书请求
	// openssl req -new -key Ca.key -out Ca.csr -subj "/C=CN/ST=BeiJing/L=BeiJing/O=xxx/OU=dev/CN=CaRoot/emailAddress=CaRoot@xxx.com"
	keyFilePath := GetKeyFilePath(id)
	csrFilePath := GetCsrFilePath(id)
	// 创建命令
	// xcmd := exec.Command(OPENSSL_PATH, "req", "-new", "-key", keyFilePath, "-out", csrFilePath, "-subj", subject)
	args := []string{"req", "-new", "-key", keyFilePath, "-out", csrFilePath, "-subj", subject}
	// if len(sans) > 0 {
	// 	sanStr := joinSans(sans)
	// 	args = append(args, "-addext", "subjectAltName = "+sanStr)
	// }
	xcmd := exec.Command(OPENSSL_PATH, args...)
	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr
	// 执行命令
	err := xcmd.Run()
	if err != nil {
		return "", fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}
	return id, nil
}

// 生成证书
func GenerateCert(id string, days int) (string, error) {
	// 生成证书
	// openssl x509 -req -in Ca.csr -signkey Ca.key -out Ca.crt
	// openssl ca -config ca.conf -notext -batch -in ./subordinate/Ca.csr -out ./subordinate/Ca.crt
	csrFilePath := GetCsrFilePath(id)
	certFilePath := GetCertFilePath(id)
	xargs := []string{
		"ca",
		"-config", CA_CONFIG,
		"-notext",
		"-batch",
		"-in", csrFilePath,
		"-out", certFilePath,
	}
	if days > 0 && days < 3650 {
		xargs = append(xargs, "-days", fmt.Sprintf("%d", days))
	}

	// 创建命令
	xcmd := exec.Command(OPENSSL_PATH, xargs...)

	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr

	// 执行命令
	err := xcmd.Run()
	if err != nil {
		return "", fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}
	return id, nil
}

// 生成黑名单
func GenerateCrl(id string) (string, error) {
	// 生成黑名单
	// openssl ca -gencrl -out crl.pem -config ca.conf
	xargs := []string{
		"ca",
		"-config", CA_CONFIG,
		"-gencrl",
		"-out", CRL,
	}

	// 创建命令
	xcmd := exec.Command(OPENSSL_PATH, xargs...)

	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr

	// 执行命令
	err := xcmd.Run()
	if err != nil {
		return "", fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}
	return id, nil
}

// 撤销证书
func RevokeCert(id string) (string, error) {
	// 撤销证书
	// openssl ca -revoke ./subordinate/Ca.crt -config ca.conf
	certFilePath := GetCertFilePath(id)
	xargs := []string{
		"ca",
		"-config", CA_CONFIG,
		"-revoke", certFilePath,
	}

	// 创建命令
	xcmd := exec.Command(OPENSSL_PATH, xargs...)

	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr

	// 执行命令
	err := xcmd.Run()
	if err != nil {
		return "", fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}
	return id, nil
}

// 检查证书是否在黑名单中
func CheckCertInCrl(certFilePath string) (bool, error) {
	// 检查证书是否在黑名单中
	// openssl verify -CAfile /opt/arrokoth/ca-mini/ca/CaRoot.crt -CRLfile /opt/arrokoth/ca-mini/crl/CaRoot.crl /opt/arrokoth/ca-mini/cert/17455454097526357682Q7pIOUE70I.crt
	// openssl crl -in crl.pem -noout -text
	xargs := []string{
		"crl",
		"-in", certFilePath,
		"-noout",
		"-text",
	}

	// 创建命令
	xcmd := exec.Command(OPENSSL_PATH, xargs...)

	// 捕获标准输出和标准错误
	var stdout, stderr bytes.Buffer
	xcmd.Stdout = &stdout
	xcmd.Stderr = &stderr

	// 执行命令
	err := xcmd.Run()
	if err != nil {
		return false, fmt.Errorf("命令执行失败: %v\n错误输出: %s", err, stderr.String())
	}
	return true, nil
}

// 读取文件内容
func ReadFile(filePath string) (string, error) {
	data, err := os.ReadFile(filePath)
	if err != nil {
		return "", fmt.Errorf("读取文件失败: %v", err)
	}
	// 将数据转换为字符串
	content := string(data)
	return content, nil
}

// 读取CA证书
func GetCaCert() (string, error) {
	data, err := ReadFile(CA_CERT)
	if err != nil {
		return "", fmt.Errorf("读取CA证书失败: %v", err)
	}
	return data, nil
}

// 读取证书
func GetCert(id string) (string, error) {
	data, err := ReadFile(GetCertFilePath(id))
	if err != nil {
		return "", fmt.Errorf("读取证书失败: %v", err)
	}
	return data, nil
}

// 读取私钥
func GetKey(id string) (string, error) {
	data, err := ReadFile(GetKeyFilePath(id))
	if err != nil {
		return "", fmt.Errorf("读取私钥失败: %v", err)
	}
	return data, nil
}

// 读取证书请求
func GetCsr(id string) (string, error) {
	data, err := ReadFile(GetCsrFilePath(id))
	if err != nil {
		return "", fmt.Errorf("读取证书请求失败: %v", err)
	}
	return data, nil
}

// joinSans 拼接 SAN 字段，例如 DNS:example.com, IP:192.168.0.1
func joinSans(sans []string) string {
	result := ""
	for i, san := range sans {
		if i > 0 {
			result += ", "
		}
		result += san
	}
	return result
}