package middleware

import (
	"blazing/modules/config/model"
	config "blazing/modules/config/service"
	"bufio"
	"context"
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io"
	"net"
	"strings"
	"sync/atomic"
	"time"

	"github.com/gogf/gf/v2/os/glog"
	"github.com/gogf/gf/v2/util/grand"
	"github.com/lxzan/gws"
	"golang.org/x/crypto/ssh"
)

const (
	PingInterval    = 10 * time.Second
	defaultWorkDir  = "$HOME"           // 全环境兼容
	randomStrLength = 4                 // 缩短随机串长度
	cmdTimeout      = 120 * time.Second // 延长超时（适配Screen安装+下载）
)

// SSHConfig SSH连接配置
type SSHConfig struct {
	ServerIP string `json:"server_ip"`
	Port     string `json:"port"`
	Username string `json:"username"`
	Password string `json:"password"`
}

// WebSSHMessage 消息结构
type WebSSHMessage struct {
	Type    string `json:"type"`
	Payload string `json:"payload"`
}

// TerminalSession 会话结构体（优化通道）
type TerminalSession struct {
	WebSocket  *gws.Conn
	SSHClient  *ssh.Client
	SSHSession *ssh.Session
	Stdin      io.WriteCloser
	Stdout     io.Reader
	Ready      bool
	outputBuf  chan string // 增大通道缓存
	closed     atomic.Bool
}

type ServerHandler struct {
	gws.BuiltinEventHandler
	session *TerminalSession
	model.ServerList
	isinstall uint32
	target    net.Conn
}

// 生成随机文件名
func (s *ServerHandler) generateRandomFileName() string {
	randBytes := make([]byte, randomStrLength)
	_, err := rand.Read(randBytes)
	if err != nil {
		return fmt.Sprintf("logic_%d", time.Now().UnixNano())
	}
	randStr := hex.EncodeToString(randBytes)
	timestamp := time.Now().Format("20060102150405")
	return fmt.Sprintf("logic_%s_%s", timestamp, randStr)
}

// 执行脚本命令
func (s *ServerHandler) executeScript(scriptContent, scriptName string) (string, error) {
	if s.session == nil || s.session.closed.Load() || !s.session.Ready {
		return "", fmt.Errorf("session not ready")
	}

	// 生成临时脚本路径
	scriptPath := fmt.Sprintf("/tmp/%s.sh", scriptName)

	// 直接将脚本内容写入文件
	writeScriptCmd := fmt.Sprintf("cat > '%s' << 'DEPLOYMENT_SCRIPT_END'\n%s\nDEPLOYMENT_SCRIPT_END\n", scriptPath, scriptContent)
	_, err := s.session.Stdin.Write([]byte(writeScriptCmd))
	if err != nil {
		return "", err
	}

	// 等待一会儿确保脚本写入完成
	time.Sleep(time.Second)

	// 设置执行权限
	_, err = s.session.Stdin.Write([]byte(fmt.Sprintf("chmod +x %s\n", scriptPath)))
	if err != nil {
		return "", err
	}

	// 等待权限设置完成
	time.Sleep(time.Second)

	// 执行脚本并将输出发送到WebSocket（在命令中直接删除脚本文件）
	executeCmd := fmt.Sprintf("bash %s 2>&1; rm -f %s\n", scriptPath, scriptPath)
	_, err = s.session.Stdin.Write([]byte(executeCmd))
	if err != nil {
		return "", err
	}

	// 读取脚本执行输出
	output := ""
	done := make(chan bool)

	go func() {
		defer func() {
			if r := recover(); r != nil {
				glog.Error(context.Background(), "Script execution goroutine panic:", r)
			}
		}()

		scanner := bufio.NewScanner(s.session.Stdout)
		for scanner.Scan() {
			line := scanner.Text()

			// 检测到脚本执行完成标记则退出
			if strings.Contains(line, "#SCRIPT_EXECUTION_COMPLETE#") {
				break
			}

			// 忽略一些可能导致连接断开的输出
			if strings.Contains(line, "logout") || strings.Contains(line, "exit") {
				continue
			}

			output += line + "\n"
			s.sendTerminalOutput(s.session.WebSocket, line)
		}
		done <- true
	}()

	// 等待脚本执行完成或超时
	select {
	case <-done:
		return strings.TrimSpace(output), nil
	case <-time.After(cmdTimeout):
		return strings.TrimSpace(output), nil
	}
}

// 执行完整的自动化部署流程
func (s *ServerHandler) executeFullDeployment() error {
	s.sendTerminalOutput(s.session.WebSocket, "开始执行完整自动化部署流程...")

	// 获取下载链接
	fileURL := config.NewServerService().GetFile()
	if strings.TrimSpace(fileURL) == "" {
		return fmt.Errorf("下载链接为空")
	}

	// 生成随机文件名
	randomFileName := s.generateRandomFileName()
	remoteExePath := fmt.Sprintf("%s/%s", defaultWorkDir, randomFileName)
	onlineID := fmt.Sprintf("%d", s.ServerList.OnlineID)

	// 创建完整的部署脚本（不包含#!/bin/bash）
	deploymentScript := fmt.Sprintf(`

set -e  # 遇到错误立即退出

# ===== 检查并安装 screen =====
echo "检查Screen是否已安装..."
if command -v screen &> /dev/null; then
    echo "=== Screen已安装，跳过 ==="
else
    echo "=== Screen未安装，开始安装 ==="
    
    if command -v apt &> /dev/null; then
        echo "检测到apt，正在更新软件包列表..."
        apt update -y > /dev/null 2>&1
        echo "正在安装screen..."
        apt install -y screen > /dev/null 2>&1
    elif command -v yum &> /dev/null; then
        echo "检测到yum，正在安装screen..."
        yum install -y screen > /dev/null 2>&1
    elif command -v dnf &> /dev/null; then
        echo "检测到dnf，正在安装screen..."
        dnf install -y screen > /dev/null 2>&1
    elif command -v pacman &> /dev/null; then
        echo "检测到pacman，正在安装screen..."
        pacman -S --noconfirm screen > /dev/null 2>&1
    else
        echo "=== 不支持的系统包管理器，无法自动安装Screen ==="
        exit 1
    fi

    if command -v screen &> /dev/null; then
        echo "=== screen 安装成功！ ==="
    else
        echo "=== screen 安装失败 ==="
        exit 1
    fi
fi

# ===== 停止旧Screen会话 =====
if [ -n "%s" ] && [ "%s" != "" ]; then
    echo "检查并停止旧会话: %s"
    if screen -ls | grep -q "%s"; then
        echo "发现旧会话，正在停止: %s"
        screen -S %s -X quit 2>/dev/null || true
#pkill -f "%s" 2>/dev/null || true
 # 可选：等待几秒，确认会话是否退出（仅提示，不强制）
        sleep 5
        
        # 检查会话是否仍存在（仅告知状态，不做强制操作）
        if screen -ls | grep -q "$SESSION_NAME"; then
            echo "⚠️  警告：旧会话未退出（进程可能正在执行清理逻辑），未执行强制杀死，请手动确认"
        else
            echo "=== 旧会话优雅停止成功 ==="
        fi
        echo "=== 旧会话已停止 ==="
    else
        echo "=== 旧会话不存在，无需停止 ==="
    fi
else
    echo "无旧Screen会话，跳过停止"
fi

# ===== 下载程序 =====
echo "开始下载程序到: %s"

# 删除旧文件
if [ -f "%s" ]; then
    echo "删除旧文件..."
    rm -f "%s"
fi

echo "开始下载..."

if command -v wget >/dev/null 2>&1; then
    wget --no-check-certificate -O "%s" "%s" 2>&1
elif command -v curl >/dev/null 2>&1; then
    curl -L -o "%s" "%s" 2>&1
else
    echo "系统未安装wget或curl"
    exit 1
fi

# 验证文件
if [ -f "%s" ] && [ -s "%s" ]; then
    echo "=== 文件下载完成 ==="
    ls -la "%s"
else
    echo "=== 文件下载失败！=== "
    echo "=== 请检查下载链接是否有效 ==="
    exit 1
fi

# ===== 启动新程序 =====
echo "开始启动新程序..."

# 设置执行权限
chmod +x "%s"
if [ $? -ne 0 ]; then
    echo "设置执行权限失败"
    exit 1
fi
echo "=== 权限设置完成 ==="

# 启动Screen会话
echo "正在启动Screen会话: %s"
screen -dmS "%s" bash -c '"%s" -id=%s | tee -a "$HOME/run.log"'

# 等待一段时间确保会话启动
sleep 5

# 检查会话是否存在
if screen -ls | grep -q "%s"; then
    echo "=== 程序启动成功：Screen会话已创建 ==="
    echo "=== 会话名称：%s ==="
    screen -ls
    echo "程序已在后台Screen会话中运行"
else
    echo "=== 程序启动失败：Screen会话未创建 ==="
    screen -ls
    exit 1
fi

echo "#SCRIPT_EXECUTION_COMPLETE#"
`,
		s.ServerList.OldScreen, s.ServerList.OldScreen, s.ServerList.OldScreen,
		s.ServerList.OldScreen, s.ServerList.OldScreen, s.ServerList.OldScreen,
		s.ServerList.OldScreen,
		remoteExePath,
		remoteExePath, remoteExePath,
		remoteExePath, fileURL,
		remoteExePath, fileURL,
		remoteExePath, remoteExePath, remoteExePath,
		remoteExePath,
		randomFileName, randomFileName, remoteExePath, onlineID,
		randomFileName, randomFileName)

	// 执行完整的部署脚本
	_, err := s.executeScript(deploymentScript, "full_deployment_"+grand.S(10))
	if err != nil {
		return err
	}

	// 保存会话名称
	config.NewServerService().SetServerScreen(s.ServerList.OnlineID, randomFileName)

	s.sendTerminalOutput(s.session.WebSocket, "自动化部署完成")

	return nil
}

// executeCommand 执行单个命令并返回输出
func (s *ServerHandler) executeCommand(command string) (string, error) {
	return s.executeScript(command, "cmd_"+grand.S(8))
}

// ---------------- 主流程：OnOpen（严格顺序执行） ----------------
func (s *ServerHandler) OnOpen(socket *gws.Conn) {
	// 1. 建立SSH连接
	sshConfig := &ssh.ClientConfig{
		User:            s.ServerList.Account,
		Auth:            []ssh.AuthMethod{ssh.Password(s.ServerList.Password)},
		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
		Timeout:         30 * time.Second,
	}

	// 连接服务器（重试）
	var sshClient *ssh.Client
	var err error
	for retry := 0; retry < 2; retry++ {
		sshClient, err = ssh.Dial("tcp", s.ServerList.LoginAddr, sshConfig)
		if err == nil {
			break
		}
		time.Sleep(3 * time.Second)
	}
	if err != nil {
		s.sendError(socket, "SSH连接失败："+err.Error())
		return
	}

	// 创建会话（重试）
	var session *ssh.Session
	for retry := 0; retry < 2; retry++ {
		session, err = sshClient.NewSession()
		if err == nil {
			break
		}
		time.Sleep(3 * time.Second)
	}
	if err != nil {
		session.Close()
		sshClient.Close()
		s.sendError(socket, "创建SSH会话失败："+err.Error())
		return
	}

	// 配置PTY（通用配置）
	modes := ssh.TerminalModes{
		ssh.ECHO:          1,
		ssh.TTY_OP_ISPEED: 115200,
		ssh.TTY_OP_OSPEED: 115200,
	}
	err = session.RequestPty("vt100", 100, 80, modes)
	if err != nil {
		session.Close()
		sshClient.Close()
		s.sendError(socket, "PTY请求失败："+err.Error())
		return
	}

	// 获取Stdin/Stdout
	stdin, err := session.StdinPipe()
	if err != nil {
		session.Close()
		sshClient.Close()
		s.sendError(socket, "获取Stdin失败："+err.Error())
		return
	}
	stdout, err := session.StdoutPipe()
	if err != nil {
		session.Close()
		sshClient.Close()
		s.sendError(socket, "获取Stdout失败："+err.Error())
		return
	}

	// 启动Shell
	err = session.Shell()
	if err != nil {
		session.Close()
		sshClient.Close()
		s.sendError(socket, "启动Shell失败："+err.Error())
		return
	}

	// 初始化会话
	s.session = &TerminalSession{
		WebSocket:  socket,
		SSHClient:  sshClient,
		SSHSession: session,
		Stdin:      stdin,
		Stdout:     stdout,
		Ready:      true,
		outputBuf:  make(chan string, 2048), // 增大缓存
		closed:     atomic.Bool{},
	}

	// 启动输出转发协程
	s.startOutputForwarding()

	s.sendSuccess(socket, "SSH连接成功，会话已就绪")

	// ---------------- 严格按顺序执行自动化部署 ----------------
	if s.isinstall == 1 {
		// 执行完整的自动化部署脚本
		err := s.executeFullDeployment()
		if err != nil {
			s.sendError(socket, "自动化部署失败: "+err.Error())
			return
		}

		s.sendSuccess(socket, "自动化部署完成")
	}
}

// startOutputForwarding 启动输出转发协程
func (s *ServerHandler) startOutputForwarding() {
	if s.session == nil {
		return
	}

	go func() {
		defer func() {
			if r := recover(); r != nil {
				glog.Error(context.Background(), "Output forwarding goroutine panic:", r)
			}
		}()

		scanner := bufio.NewScanner(s.session.Stdout)
		for scanner.Scan() {
			line := scanner.Text()
			s.sendTerminalOutput(s.session.WebSocket, line+"\r\n")
		}

		if err := scanner.Err(); err != nil && s.session != nil {
			glog.Error(context.Background(), "读取 SSH 输出失败:", err)
			s.sendError(s.session.WebSocket, "读取 SSH 输出失败: "+err.Error())
		}
	}()
}

// ---------------- 基础函数 ----------------
func (s *ServerHandler) OnMessage(socket *gws.Conn, gwsmessage *gws.Message) {
	if s.session == nil || s.session.Stdin == nil {
		s.sendError(socket, "SSH 会话未建立")
		return
	}

	_, err := s.session.Stdin.Write([]byte(gwsmessage.Data.Bytes()))
	if err != nil {
		s.sendError(socket, "写入消息失败："+err.Error())
	}
}

func (s *ServerHandler) OnClose(socket *gws.Conn, err error) {
	glog.Debug(context.Background(), "连接断开:", err)
	if s.session != nil {
		s.session.closed.Store(true)
		if s.session.SSHSession != nil {
			s.session.SSHSession.Close()
		}
		if s.session.SSHClient != nil {
			s.session.SSHClient.Close()
		}
		s.session = nil
	}
}

// 发送终端输出
func (s *ServerHandler) sendTerminalOutput(ws *gws.Conn, output string) {
	msg := WebSSHMessage{Type: "output", Payload: output}
	data, _ := json.Marshal(msg)
	ws.WriteMessage(gws.OpcodeText, data)
}

// 发送成功消息
func (s *ServerHandler) sendSuccess(ws *gws.Conn, msg string) {
	res := WebSSHMessage{Type: "success", Payload: msg}
	data, _ := json.Marshal(res)
	ws.WriteMessage(gws.OpcodeText, data)
}

// 发送错误消息
func (s *ServerHandler) sendError(ws *gws.Conn, msg string) {
	res := WebSSHMessage{Type: "error", Payload: msg}
	data, _ := json.Marshal(res)
	ws.WriteMessage(gws.OpcodeText, data)
}