package vnc

import (
	"context"
	"fmt"
	"net"
	"time"

	"github.com/mitchellh/go-vnc"
	"github.com/shadow1ng/fscan/common"
	"github.com/shadow1ng/fscan/common/i18n"
	"github.com/shadow1ng/fscan/plugins/base"
)

// VNCConnector VNC服务连接器
type VNCConnector struct{}

// NewVNCConnector 创建新的VNC连接器
func NewVNCConnector() *VNCConnector {
	return &VNCConnector{}
}

// Connect 连接到VNC服务
func (c *VNCConnector) Connect(ctx context.Context, info *common.HostInfo) (interface{}, error) {
	target := fmt.Sprintf("%s:%s", info.Host, info.Ports)
	timeout := time.Duration(common.Timeout) * time.Second

	// 使用带上下文的TCP连接
	conn, err := common.WrapperTcpWithTimeout("tcp", target, timeout)
	if err != nil {
		return nil, fmt.Errorf(i18n.GetText("vnc_connection_failed"), err)
	}

	// 设置读写超时
	if err := conn.SetDeadline(time.Now().Add(timeout)); err != nil {
		conn.Close()
		return nil, fmt.Errorf("failed to set connection deadline: %v", err)
	}

	return conn, nil
}

// Authenticate 认证VNC服务
func (c *VNCConnector) Authenticate(ctx context.Context, conn interface{}, cred *base.Credential) error {
	netConn, ok := conn.(net.Conn)
	if !ok {
		return fmt.Errorf("invalid connection type")
	}

	// 检查上下文是否已取消
	select {
	case <-ctx.Done():
		return ctx.Err()
	default:
	}

	// VNC只使用密码认证，忽略用户名
	password := cred.Password
	if password == "" && cred.Username != "" {
		// 如果密码为空但用户名不为空，尝试使用用户名作为密码
		password = cred.Username
	}

	// 创建完成通道
	doneChan := make(chan error, 1)

	// 在协程中处理VNC认证
	go func() {
		// 配置VNC客户端
		config := &vnc.ClientConfig{
			Auth: []vnc.ClientAuth{
				&vnc.PasswordAuth{
					Password: password,
				},
			},
		}

		// 尝试VNC认证
		client, err := vnc.Client(netConn, config)
		if err != nil {
			select {
			case <-ctx.Done():
			case doneChan <- err:
			}
			return
		}

		// 认证成功，立即关闭客户端
		client.Close()
		select {
		case <-ctx.Done():
		case doneChan <- nil:
		}
	}()

	// 等待认证结果或上下文取消
	select {
	case err := <-doneChan:
		return err
	case <-ctx.Done():
		return ctx.Err()
	}
}

// Close 关闭连接
func (c *VNCConnector) Close(conn interface{}) error {
	if closer, ok := conn.(interface{ Close() error }); ok && closer != nil {
		return closer.Close()
	}
	return nil
}