package Plugins

import (
	"fmt"
	"github.com/mitchellh/go-vnc"
	"github.com/shadow1ng/fscan/Common"
	"net"
	"sync"
	"time"
)

// VncScan 执行VNC服务扫描及密码尝试
func VncScan(info *Common.HostInfo) (tmperr error) {
	if Common.DisableBrute {
		return
	}

	maxRetries := Common.MaxRetries
	threads := Common.BruteThreads
	modename := "vnc"

	// 创建任务通道
	taskChan := make(chan string, len(Common.Passwords))
	resultChan := make(chan error, threads)

	// 生成所有密码任务
	for _, pass := range Common.Passwords {
		taskChan <- pass
	}
	close(taskChan)

	// 启动工作线程
	var wg sync.WaitGroup
	for i := 0; i < threads; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			starttime := time.Now().Unix()

			for pass := range taskChan {
				// 重试循环
				for retryCount := 0; retryCount < maxRetries; retryCount++ {
					// 检查是否超时
					if time.Now().Unix()-starttime > int64(Common.Timeout) {
						resultChan <- fmt.Errorf("扫描超时")
						return
					}

					// 执行VNC连接
					done := make(chan struct {
						success bool
						err     error
					})

					go func(pass string) {
						success, err := VncConn(info, pass)
						done <- struct {
							success bool
							err     error
						}{success, err}
					}(pass)

					// 等待结果或超时
					var err error
					select {
					case result := <-done:
						err = result.err
						if result.success && err == nil {
							// 连接成功
							successLog := fmt.Sprintf("%s://%v:%v 密码: %v",
								modename, info.Host, info.Ports, pass)
							Common.LogSuccess(successLog)
							resultChan <- nil
							return
						}
					case <-time.After(time.Duration(Common.Timeout) * time.Second):
						err = fmt.Errorf("连接超时")
					}

					// 处理错误情况
					if err != nil {
						errlog := fmt.Sprintf("%s://%v:%v 尝试密码: %v 错误: %v",
							modename, info.Host, info.Ports, pass, err)
						Common.LogError(errlog)

						// 检查是否是需要重试的错误
						if retryErr := Common.CheckErrs(err); retryErr != nil {
							if retryCount == maxRetries-1 {
								resultChan <- err
								return
							}
							continue // 继续重试
						}
					}

					break // 如果不需要重试，跳出重试循环
				}
			}
			resultChan <- nil
		}()
	}

	// 等待所有线程完成
	go func() {
		wg.Wait()
		close(resultChan)
	}()

	// 检查结果
	for err := range resultChan {
		if err != nil {
			tmperr = err
			if retryErr := Common.CheckErrs(err); retryErr != nil {
				return err
			}
		}
	}

	return tmperr
}

// VncConn 尝试建立VNC连接
func VncConn(info *Common.HostInfo, pass string) (flag bool, err error) {
	flag = false
	Host, Port := info.Host, info.Ports

	// 建立TCP连接
	conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%s", Host, Port),
		time.Duration(Common.Timeout)*time.Second)
	if err != nil {
		return
	}
	defer conn.Close()

	// 配置VNC客户端
	config := &vnc.ClientConfig{
		Auth: []vnc.ClientAuth{
			&vnc.PasswordAuth{
				Password: pass,
			},
		},
	}

	// 尝试VNC认证
	client, err := vnc.Client(conn, config)
	if err == nil {
		defer client.Close()
		flag = true
	}

	return
}