package logger

import (
	"bytes"
	"encoding/json"
	"fmt"
	"gitea.baoapi.com/root/stu_uuos/config"
	rotatelogs "github.com/lestrrat-go/file-rotatelogs"
	"github.com/rifflock/lfshook"
	"github.com/sirupsen/logrus"
	"os"
	"path"
	"path/filepath"
	"regexp"
	"runtime"
	"strings"
	"time"
)

const (
	nocolor logColor = 0
	red     logColor = 31
	green   logColor = 32
	yellow  logColor = 33
	blue    logColor = 36
	gray    logColor = 37
)

type TextLogFormatter struct {
	Conf *config.Config
}

type logOutTarget string
type logFormatter string
type logLevel string
type logColor int

const (
	Std  logOutTarget = "std"
	File logOutTarget = "file"
)
const (
	Text logFormatter = "text"
	Json logFormatter = "json"
)
const (
	Unknown logLevel = "UNKNOWN"
	Trc     logLevel = "TRC"
	Dbg     logLevel = "DBG"
	Inf     logLevel = "INF"
	Wrn     logLevel = "WRN"
	Err     logLevel = "ERR"
	Fat     logLevel = "FAT"
	Pan     logLevel = "PAN"
)

func newLogrusLogger() *logrus.Logger {
	conf := config.GetConfig()
	logger := logrus.New()

	lvl, err := logrus.ParseLevel(conf.Log.MinLevel)
	if err != nil {
		panic(err)
	}

	logger.Level = lvl
	logger.ReportCaller = conf.Log.ReportCaller

	if conf.Log.Formatter == string(Text) {
		logger.Formatter = &TextLogFormatter{conf}
	} else {
		logger.Formatter = &logrus.JSONFormatter{
			TimestampFormat: conf.Log.TimestampFormat,
			PrettyPrint:     conf.Log.JsonPrettyPrint,
			CallerPrettyfier: func(f *runtime.Frame) (string, string) {
				filename, line, funcName := getRuntimeLocation()

				if len(filename) == 0 {
					_, filename = path.Split(f.File)
				} else {
					filename = fmt.Sprintf("%s:%d", filename, line)
				}

				if len(funcName) == 0 {
					s := strings.Split(f.Function, ".")
					funcName = s[len(s)-1]
				}

				return funcName, filename
			},
		}
	}

	if conf.Log.Out == string(File) {
		hook := newLfsHook(conf, logger.Formatter)
		logger.AddHook(hook)
	} else {
		logger.SetOutput(os.Stdout)
	}

	return logger
}

func (f *TextLogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
	var b *bytes.Buffer

	if entry.Buffer != nil {
		b = entry.Buffer
	} else {
		b = &bytes.Buffer{}
	}

	lt, lc := parseLevel(entry)
	fn, line, funcName := getEntryRuntimeLocation(entry)
	caller := ""

	if entry.HasCaller() && f.Conf.Log.ReportCaller {
		caller = fmt.Sprintf("%s:%d %s", fn, line, funcName)
	}

	if f.Conf.Log.Out == string(Std) && f.Conf.Log.OutColor { //只有控制台输出才需要输出颜色，文件输出不需要颜色。
		_, err := fmt.Fprintf(b, "%s \x1b[%dm[%s] \x1b[0m%s - %s ",
			entry.Time.Format(f.Conf.Log.TimestampFormat), lc, lt, caller, entry.Message)
		if err != nil {
			panic(err)
		}
	} else {
		_, err := fmt.Fprintf(b, "%s [%s] %s | %-44s ",
			entry.Time.Format(f.Conf.Log.TimestampFormat), lt, caller, entry.Message)
		if err != nil {
			panic(err)
		}
	}

	if len(entry.Data) > 0 {
		outJsonEntry(b, entry)
	}

	b.WriteByte('\n')
	return b.Bytes(), nil
}

func parseLevel(entry *logrus.Entry) (logLevel, logColor) {
	lt := Unknown
	var lc logColor

	switch entry.Level {
	case logrus.TraceLevel:
		lt = Trc
		lc = gray
	case logrus.DebugLevel:
		lt = Dbg
		lc = gray
	case logrus.InfoLevel:
		lt = Inf
		lc = blue
	case logrus.WarnLevel:
		lt = Wrn
		lc = yellow
	case logrus.ErrorLevel:
		lt = Err
		lc = red
	case logrus.FatalLevel:
		lt = Fat
		lc = red
	case logrus.PanicLevel:
		lt = Pan
		lc = red
	}

	return lt, lc
}

func outJsonEntry(b *bytes.Buffer, entry *logrus.Entry) {
	jb, err := json.Marshal(entry.Data)
	if err != nil {
		panic(err)
	}

	if _, err = fmt.Fprint(b, string(jb)); err != nil {
		panic(err)
	}
}

func newLfsHook(conf *config.Config, formatter logrus.Formatter) logrus.Hook {
	filePathName := path.Join(conf.Log.FilePath, conf.Log.FileName)

	var opts []rotatelogs.Option

	// 生成软链，指向最新日志文件
	opts = append(opts, rotatelogs.WithLinkName(filePathName))
	// 日志切割时间间隔
	du1, err := time.ParseDuration(conf.Log.RotationTime)
	if err != nil {
		panic(err)
	}

	if du1.Minutes() < 1 {
		panic(fmt.Errorf("日志切割时间 %v 太短", du1))
	}

	opts = append(opts, rotatelogs.WithRotationTime(du1))
	du2, err := time.ParseDuration(conf.Log.MaxAge)
	if err != nil {
		panic(err)
	}

	if du2.Minutes() > 0 && du2.Minutes() < 1 {
		panic(fmt.Errorf("日志保留时间 %v 太短", du1))
	}

	// WithMaxAge 和 WithRotationCount 二者只能设置一个
	if du2.Minutes() > 0 {
		// 文件最长保存时间
		opts = append(opts, rotatelogs.WithMaxAge(du2))
	} else if conf.Log.MaxRemainCount > 0 {
		//最多保存文件个数
		opts = append(opts, rotatelogs.WithRotationCount(conf.Log.MaxRemainCount))
	} else {
		// 默认设置为文件最长保存时间一个月
		opts = append(opts, rotatelogs.WithMaxAge(time.Hour*24*30))
	}

	writer, err := rotatelogs.New(filePathName+".%Y%m%d%H%M", opts...)
	if err != nil {
		panic(err)
	}

	lfsHook := lfshook.NewHook(lfshook.WriterMap{
		logrus.TraceLevel: writer,
		logrus.DebugLevel: writer,
		logrus.InfoLevel:  writer,
		logrus.WarnLevel:  writer,
		logrus.ErrorLevel: writer,
		logrus.FatalLevel: writer,
		logrus.PanicLevel: writer,
	}, formatter)

	return lfsHook
}

func getEntryRuntimeLocation(entry *logrus.Entry) (filename string, line int, funcName string) {
	filename, line, funcName = getRuntimeLocation()

	if len(filename) == 0 && line == 0 && len(funcName) == 0 {
		filename = filepath.Base(entry.Caller.File)
		line = entry.Caller.Line
		funcName = filepath.Base(entry.Caller.Function)
	}

	return filename, line, funcName
}

var logRegexp = regexp.MustCompile(`config*|model*|entity*|db*|constant*|srv*|web*|handler*|router*|util*|micro*`)
var excludeRegexp = regexp.MustCompile(`logger*|logrus*`)

// 获取正在运行的文件名称、文件所在行、函数名
func getRuntimeLocation() (filename string, line int, funcName string) {
	var pc uintptr
	var ok bool
	var i int

	for {
		pc, filename, line, ok = runtime.Caller(i)

		if ok && (logRegexp.MatchString(filename) && !excludeRegexp.MatchString(filename)) {
			funcName = runtime.FuncForPC(pc).Name()
			fns := strings.Split(funcName, "/")

			if len(fns) > 1 {
				dir := strings.Join(fns[1:len(fns)-1], "/")
				directPkg := strings.Split(fns[len(fns)-1], ".")[0]

				filename = fmt.Sprintf("%s/%s/%s", dir, directPkg, filepath.Base(filename))
			}

			funcName = filepath.Base(funcName)
			break
		}

		i++
	}

	return filename, line, funcName
}