package Plugins

import (
	"fmt"
	"github.com/shadow1ng/fscan/Common"
	"net"
	"strings"
	"sync"
	"time"
)

// RsyncScan 执行 Rsync 服务扫描
func RsyncScan(info *Common.HostInfo) (tmperr error) {
	if Common.DisableBrute {
		return
	}

	maxRetries := Common.MaxRetries
	threads := Common.BruteThreads

	// 首先测试匿名访问
	for retryCount := 0; retryCount < maxRetries; retryCount++ {
		flag, err := RsyncConn(info, "", "")
		if flag && err == nil {
			return err
		}

		if err != nil {
			if retryErr := Common.CheckErrs(err); retryErr != nil {
				if retryCount == maxRetries-1 {
					return err
				}
				continue
			}
		}
		break
	}

	// 创建任务通道
	taskChan := make(chan struct {
		user string
		pass string
	}, len(Common.Userdict["rsync"])*len(Common.Passwords))

	resultChan := make(chan error, threads)

	// 生成所有用户名密码组合任务
	for _, user := range Common.Userdict["rsync"] {
		for _, pass := range Common.Passwords {
			pass = strings.Replace(pass, "{user}", user, -1)
			taskChan <- struct {
				user string
				pass string
			}{user, 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 task := 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Rsync连接
					done := make(chan struct {
						success bool
						err     error
					})

					go func(user, pass string) {
						flag, err := RsyncConn(info, user, pass)
						done <- struct {
							success bool
							err     error
						}{flag && err == nil, err}
					}(task.user, task.pass)

					// 等待结果或超时
					var err error
					select {
					case result := <-done:
						err = result.err
						if result.success {
							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("[-] Rsync服务 %v:%v 尝试失败 用户名: %v 密码: %v 错误: %v",
							info.Host, info.Ports, task.user, task.pass, err)
						Common.LogError(errlog)

						// 检查是否需要重试
						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
}

func RsyncConn(info *Common.HostInfo, user string, pass string) (bool, error) {
	host, port := info.Host, info.Ports
	timeout := time.Duration(Common.Timeout) * time.Second

	// 建立连接
	conn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%s", host, port), timeout)
	if err != nil {
		return false, err
	}
	defer conn.Close()

	buffer := make([]byte, 1024)

	// 1. 读取服务器初始greeting
	n, err := conn.Read(buffer)
	if err != nil {
		return false, err
	}

	greeting := string(buffer[:n])
	if !strings.HasPrefix(greeting, "@RSYNCD:") {
		return false, fmt.Errorf("不是Rsync服务")
	}

	// 获取服务器版本号
	version := strings.TrimSpace(strings.TrimPrefix(greeting, "@RSYNCD:"))

	// 2. 回应相同的版本号
	_, err = conn.Write([]byte(fmt.Sprintf("@RSYNCD: %s\n", version)))
	if err != nil {
		return false, err
	}

	// 3. 选择模块 - 先列出可用模块
	_, err = conn.Write([]byte("#list\n"))
	if err != nil {
		return false, err
	}

	// 4. 读取模块列表
	var moduleList strings.Builder
	for {
		n, err = conn.Read(buffer)
		if err != nil {
			break
		}
		chunk := string(buffer[:n])
		moduleList.WriteString(chunk)
		if strings.Contains(chunk, "@RSYNCD: EXIT") {
			break
		}
	}

	modules := strings.Split(moduleList.String(), "\n")
	for _, module := range modules {
		if strings.HasPrefix(module, "@RSYNCD") || module == "" {
			continue
		}

		// 获取模块名
		moduleName := strings.Fields(module)[0]

		// 5. 为每个模块创建新连接尝试认证
		authConn, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%s", host, port), timeout)
		if err != nil {
			continue
		}
		defer authConn.Close()

		// 重复初始握手
		_, err = authConn.Read(buffer)
		if err != nil {
			authConn.Close()
			continue
		}

		_, err = authConn.Write([]byte(fmt.Sprintf("@RSYNCD: %s\n", version)))
		if err != nil {
			authConn.Close()
			continue
		}

		// 6. 选择模块
		_, err = authConn.Write([]byte(moduleName + "\n"))
		if err != nil {
			authConn.Close()
			continue
		}

		// 7. 等待认证挑战
		n, err = authConn.Read(buffer)
		if err != nil {
			authConn.Close()
			continue
		}

		authResponse := string(buffer[:n])
		if strings.Contains(authResponse, "@RSYNCD: OK") {
			// 模块不需要认证
			if user == "" && pass == "" {
				result := fmt.Sprintf("[+] Rsync服务 %v:%v 模块:%v 无需认证", host, port, moduleName)
				Common.LogSuccess(result)
				return true, nil
			}
		} else if strings.Contains(authResponse, "@RSYNCD: AUTHREQD") {
			if user != "" && pass != "" {
				// 8. 发送认证信息
				authString := fmt.Sprintf("%s %s\n", user, pass)
				_, err = authConn.Write([]byte(authString))
				if err != nil {
					authConn.Close()
					continue
				}

				// 9. 读取认证结果
				n, err = authConn.Read(buffer)
				if err != nil {
					authConn.Close()
					continue
				}

				if !strings.Contains(string(buffer[:n]), "@ERROR") {
					result := fmt.Sprintf("[+] Rsync服务 %v:%v 模块:%v 认证成功 用户名: %v 密码: %v",
						host, port, moduleName, user, pass)
					Common.LogSuccess(result)
					return true, nil
				}
			}
		}
		authConn.Close()
	}

	return false, fmt.Errorf("认证失败或无可用模块")
}