# PowerShell 脚本：生成自签名证书

# 处理命令行参数
param(
    [Parameter(HelpMessage="证书有效期(天数)")]
    [int]$days = 365,
    
    [Parameter(HelpMessage="证书主题")]
    [string]$subject = "CN=localhost,OU=Test,O=GoProxy,L=Shanghai,S=Shanghai,C=CN",
    
    [Parameter(HelpMessage="公用名(CN)")]
    [string]$cn = "",
    
    [Parameter(HelpMessage="显示帮助信息")]
    [switch]$help
)

# 帮助信息
function Show-Help {
    Write-Host "生成自签名证书"
    Write-Host
    Write-Host "用法: .\generate_cert.ps1 [选项]"
    Write-Host
    Write-Host "选项:"
    Write-Host "  -help            显示此帮助信息"
    Write-Host "  -days DAYS       证书有效期(天数)，默认: 365"
    Write-Host "  -subject SUB     证书主题，默认: $subject"
    Write-Host "  -cn CN           公用名(CN)，将替换主题中的CN，默认: localhost"
    Write-Host
    Write-Host "示例:"
    Write-Host "  .\generate_cert.ps1 -days 730 -cn example.com"
    Write-Host
}

# 如果请求帮助，显示帮助信息并退出
if ($help) {
    Show-Help
    exit 0
}

# 如果指定了CN，替换主题中的CN部分
if ($cn -ne "") {
    $subject = $subject -replace "CN=[^,]*", "CN=$cn"
}

Write-Host "生成自签名证书..."
Write-Host "有效期: $days 天"
Write-Host "主题: $subject"

# 检查OpenSSL是否可用
$openssl = Get-Command "openssl" -ErrorAction SilentlyContinue
if (-not $openssl) {
    Write-Host "错误: 未找到OpenSSL命令。请安装OpenSSL并确保它在PATH环境变量中。" -ForegroundColor Red
    Write-Host "您可以从以下地址下载OpenSSL for Windows: https://slproweb.com/products/Win32OpenSSL.html" -ForegroundColor Yellow
    exit 1
}

try {
    # 生成私钥
    Write-Host "正在生成私钥..." -ForegroundColor Cyan
    & openssl genrsa -out server.key 2048

    # 生成证书请求
    Write-Host "正在生成证书请求..." -ForegroundColor Cyan
    & openssl req -new -key server.key -out server.csr -subj $subject.Replace(",", "/")

    # 生成自签名证书
    Write-Host "正在生成自签名证书..." -ForegroundColor Cyan
    & openssl x509 -req -days $days -in server.csr -signkey server.key -out server.crt

    # 删除证书请求文件
    Remove-Item server.csr -Force

    Write-Host "完成！已生成以下文件:" -ForegroundColor Green
    Write-Host " - server.key: 私钥" -ForegroundColor Green
    Write-Host " - server.crt: 证书" -ForegroundColor Green
    Write-Host
    Write-Host "您可以使用这些文件启动HTTPS代理:" -ForegroundColor Cyan
    Write-Host "go run cmd/custom_dns_https_proxy/main.go -cert server.crt -key server.key" -ForegroundColor Cyan
}
catch {
    Write-Host "错误: 生成证书时发生错误: $_" -ForegroundColor Red
    exit 1
}