package lormatter

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

	"github.com/sirupsen/logrus"
)

var (
	workspace string // 工作目录
)

func init() {
	workspace, _ = os.Getwd()
	workspace = filepath.ToSlash(workspace)
}

// Formatter implements logrus.Formatter interface.
type Formatter struct {
	ShowTime   bool   // show time
	ShowFile   bool   // show file name and line
	ShowFunc   bool   // show func name when call
	ShowField  bool   // show custom field
	TimeLayout string // time layout
}

func (f *Formatter) shortLevel(level logrus.Level) string {
	switch level {
	case logrus.DebugLevel:
		return "DEBU"
	case logrus.InfoLevel:
		return "INFO"
	case logrus.WarnLevel:
		return "WARN"
	case logrus.ErrorLevel:
		return "ERRO"
	case logrus.FatalLevel:
		return "FATAL"
	case logrus.PanicLevel:
		return "PANIC"
	default:
		return "INFO"
	}
}

// Format building log message.
func (f *Formatter) Format(entry *logrus.Entry) ([]byte, error) {
	var builder bytes.Buffer

	if f.ShowTime {
		if f.TimeLayout == "" {
			f.TimeLayout = time.DateTime
		}
		builder.WriteString(entry.Time.Format(f.TimeLayout))
		builder.WriteString(" ")
	}

	if f.ShowFile {
		content := fmt.Sprintf("[%s:%d] ", strings.ReplaceAll(entry.Caller.File, workspace, "."),
			entry.Caller.Line)
		builder.WriteString(content)
	}

	if f.ShowFunc {
		s := strings.Split(entry.Caller.Function, ".")
		content := fmt.Sprintf("[%s()] ", s[len(s)-1])
		builder.WriteString(content)
	}

	builder.WriteString("[" + f.shortLevel(entry.Level) + "] ")

	if f.ShowField {
		for k, val := range entry.Data {
			builder.WriteString(fmt.Sprintf("[%s=%v] ", k, val))
		}
	}

	builder.WriteString(entry.Message)
	builder.WriteRune('\n')
	return builder.Bytes(), nil
}

// Register auto set formatter object for logrus.
func (f *Formatter) Register() {
	logrus.SetFormatter(f)
	logrus.SetReportCaller(true)
}