package main

import (
    "fmt"
    "path"
    "os"
    "bufio"
    "time"
    
   rotatelogs "github.com/lestrrat-go/file-rotatelogs"  /* 引入日志回滚功能 */
    "github.com/rifflock/lfshook"   /* logrus本地文件系统钩子 */
    "github.com/sirupsen/logrus"    /* logrus日志包 */
)

/* 定义日志级别 */
const LOG_TRACE = 0
const LOG_DEBUG = 1
const LOG_INFO  = 2
const LOG_WARN  = 3
const LOG_ERROR = 4
const LOG_FATAL = 5
const LOG_PANIC = 6

/* 创建logrus日志实例 */
var Logger = logrus.New()

/* 使用闭包特性，初始化带回滚功能的logrus日志环境 */
func LoggerToFile() func(int, ...interface{}){
 /* 日志路径和名称 */
    logFilePath := "/home/goproject/log"
    logFileName := "helloworld"

    partFileName := path.Join(logFilePath, logFileName)

　　/* 禁止日志打印到标准输出stdout */
    devnull, err := os.OpenFile(os.DevNull, os.O_APPEND|os.O_WRONLY, os.ModeAppend)

    if err != nil {
        fmt.Printf("LoggerToFile open os.DevNull failed: ", err)
    }
    writernull := bufio.NewWriter(devnull)
    Logger.SetOutput(writernull)

 /* 设置默认日志级别为 INFO */
    Logger.SetLevel(logrus.InfoLevel)

 /* 创建日志回滚实例，日志名称格式，日志回滚模式（日志每20M回滚，保留10各日志文件） */
    logWriter, err := rotatelogs.New(
        partFileName+".%Y%m%d.log",
        rotatelogs.WithLinkName(logFileName+".log"),  /* 链接文件，链接到当前实际的日志文件  */
        rotatelogs.WithRotationSize(20*1024*1024),
        rotatelogs.WithRotationCount(10),
    )

/* 日志输出到本地文件系统，不同级别都输出到相同的日志中 */
    writeMap := lfshook.WriterMap{
        logrus.InfoLevel:  logWriter,
        logrus.FatalLevel: logWriter,
        logrus.DebugLevel: logWriter,
        logrus.WarnLevel:  logWriter,
        logrus.ErrorLevel: logWriter,
        logrus.PanicLevel: logWriter,
    }

 /* 创建新的lfs钩子 */
    lfHook := lfshook.NewHook(writeMap, &logrus.JSONFormatter{
        TimestampFormat:"2006-01-02 15:04:05",
    })

　　 /* logrus实例添加lfshook钩子 */
    Logger.AddHook(lfHook)

 /* 返回日志函数实例，这里可以根据level参数，实现不同级别的日志输出控制 */
    return func(level int, args ...interface{}) {
        loginfo := fmt.Sprintf("%v", args)
        Logger.WithFields(logrus.Fields{
            "module": "helloworld",
        }).Info(loginfo)
    }
}

/* 创建一个日志函数实例（闭包） */
var TestLog = LoggerToFile()

func main() {

    TestLog(LOG_DEBUG, "Hello, World!")
    fmt.Println("Hello, World!")
    
    count := 0
    for {
        TestLog(LOG_INFO, "No.", count, "sleep 2s......")
        fmt.Println("No.", count, "sleep 20s......")
        count++
        time.Sleep(2*time.Second)
    }
}