package main

/**
日志文件自动切换，默认保留15天内日志
**/

import (
	"log"
	"os"
	"path/filepath"
	"regexp"
	"time"

	"github.com/go-xweb/xweb"
	"github.com/robfig/cron"
)

// 日志格式
var fileReg = regexp.MustCompile("^(\\d{4}_[0-9_]{14})\\.log$")

// 当前日志文件句柄
var LogFile *os.File

// 时间格式
var FMT = "2006_01_02_15_04_05"

// 日志目录
var LogPath = "./jylog"

func init() {
	os.Mkdir(LogPath, os.ModePerm)
	//默认保留15天内的日志，-1为永久保留
	initLog(15)
}

func initLog(saveDay int) {
	go logfile()
	task := cron.New()
	task.Start()
	task.AddFunc("0 0 0/2 * * ?", func() {
		go logfile()
		time.Sleep(50 * time.Second)
		if saveDay > 0 {
			filepath.Walk(LogPath, func(path string, info os.FileInfo, err error) error {
				str := fileReg.FindStringSubmatch(info.Name())
				if len(str) == 2 {
					t, er := time.ParseInLocation(FMT, str[1], time.Local)
					if er == nil {
						if (time.Now().Unix()-t.Unix())/86400 > int64(saveDay) {
							log.Println("delete log file:", path, os.Remove(path))
						}
					}
				}
				return nil
			})
		}
	})
}

// 创建并切换输出文件
func logfile() {
	now := time.Now().Format(FMT)
	file, _ := os.Create(LogPath + "/" + now + ".log")
	log.SetOutput(file)
	xweb.RootApp().Logger.SetOutput(file)
	go func(file *os.File) {
		time.Sleep(5 * time.Second)
		if LogFile != nil {
			LogFile.Close()
		}
		LogFile = file
	}(file)
}