package main

import (
	"fmt"
	"log"
	"os"
)

// LogLevel 定义日志级别
type LogLevel int

// 日志级别常量
const (
	LogLevelInfo LogLevel = iota
	LogLevelWarn
	LogLevelError
	LogLevelDebug
)

// Logger 日志管理器
type Logger struct {
	file     *os.File
	infoLog  *log.Logger
	warnLog  *log.Logger
	errorLog *log.Logger
	debugLog *log.Logger
	level    LogLevel
}

// NewLogger 创建新的日志管理器
func NewLogger() *Logger {
	// 打开或创建日志文件，追加模式
	file, err := os.OpenFile("firewall.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
	if err != nil {
		log.Printf("Failed to open log file, using stdout: %v", err)
		file = os.Stdout
	}

	// 创建不同级别的日志记录器
	infoLog := log.New(file, "INFO: ", log.Ldate|log.Ltime|log.Lshortfile)
	warnLog := log.New(file, "WARN: ", log.Ldate|log.Ltime|log.Lshortfile)
	errorLog := log.New(file, "ERROR: ", log.Ldate|log.Ltime|log.Lshortfile)
	debugLog := log.New(file, "DEBUG: ", log.Ldate|log.Ltime|log.Lshortfile)

	return &Logger{
		file:     file,
		infoLog:  infoLog,
		warnLog:  warnLog,
		errorLog: errorLog,
		debugLog: debugLog,
		level:    LogLevelInfo, // 默认日志级别为INFO
	}
}

// SetLevel 设置日志级别
func (l *Logger) SetLevel(level LogLevel) {
	l.level = level
}

// Info 记录INFO级别日志
func (l *Logger) Info(v ...interface{}) {
	if l.level <= LogLevelInfo {
		l.infoLog.Println(v...)
	}
}

// Warn 记录WARN级别日志
func (l *Logger) Warn(v ...interface{}) {
	if l.level <= LogLevelWarn {
		l.warnLog.Println(v...)
	}
}

// Error 记录ERROR级别日志
func (l *Logger) Error(v ...interface{}) {
	if l.level <= LogLevelError {
		l.errorLog.Println(v...)
	}
}

// Debug 记录DEBUG级别日志
func (l *Logger) Debug(v ...interface{}) {
	if l.level <= LogLevelDebug {
		l.debugLog.Println(v...)
	}
}

// Close 关闭日志文件
func (l *Logger) Close() {
	if l.file != os.Stdout {
		l.file.Close()
	}
}

// LogPacket 记录数据包信息
func (l *Logger) LogPacket(rule *Rule, srcIP, dstIP string, srcPort, dstPort int, protocol Protocol, action RuleAction) {
	logMsg := fmt.Sprintf(
		"Packet matched rule %s: %s %s:%d -> %s:%d, action: %s",
		rule.ID,
		protocol,
		srcIP,
		srcPort,
		dstIP,
		dstPort,
		action,
	)

	l.Info(logMsg)
}