package util

import (
	"fmt"
	"log"
	"os"
	"runtime"
	"strings"
)

var (
	_log = NewStdOutLogger("[GO-COMMON]", 3)
)

var (
	Debugf = _log.Debugf
	Warnf  = _log.Warnf
	Infof  = _log.Infof
	Errorf = _log.Errorf
	Fatalf = _log.Fatalf
)

func Painc(err error) {
	if err != nil {
		Errorf("%v", err)
		buf := make([]byte, 64<<10)
		buf = buf[:runtime.Stack(buf, false)]
		Fatalf("Happened panic:\n%s", buf)
	}
}

type Logger interface {
	Debugf(format string, v ...interface{})
	Infof(format string, v ...interface{})
	Errorf(format string, v ...interface{})
	Warnf(format string, v ...interface{})
	Fatalf(format string, v ...interface{})
}

type stdOutLogger struct {
	*log.Logger
	caller int
}

func NewStdOutLogger(prefix string, caller int) Logger {
	if prefix != "" && !strings.HasSuffix(prefix, " ") {
		prefix = prefix + " "
	}
	if caller == 0 {
		caller = 3
	}
	return &stdOutLogger{
		Logger: log.New(os.Stdout, prefix, log.Lshortfile|log.LstdFlags),
		caller: caller,
	}
}

func (s *stdOutLogger) output(level level, str string) {
	formatStr := ""
	switch level {
	case levelFatal:
		formatStr = "\033[35m[FATAL]\033[0m " + str
	case levelError:
		formatStr = "\033[31m[ERROR]\033[0m " + str
	case levelWarning:
		formatStr = "\033[33m[WARN]\033[0m " + str
	case levelInfo:
		formatStr = "\033[32m[INFO]\033[0m " + str
	case levelDebug:
		formatStr = "\033[36m[DEBUG]\033[0m " + str
	}
	_ = s.Output(s.caller, formatStr)
}

func (s *stdOutLogger) Debugf(format string, v ...interface{}) {
	s.output(levelDebug, fmt.Sprintf(format, v...))
}

func (s *stdOutLogger) Infof(format string, v ...interface{}) {
	s.output(levelInfo, fmt.Sprintf(format, v...))
}
func (s *stdOutLogger) Warnf(format string, v ...interface{}) {
	s.output(levelWarning, fmt.Sprintf(format, v...))
}
func (s *stdOutLogger) Errorf(format string, v ...interface{}) {
	s.output(levelError, fmt.Sprintf(format, v...))
}

func (s *stdOutLogger) Fatalf(format string, v ...interface{}) {
	s.output(levelFatal, fmt.Sprintf(format, v...))
	os.Exit(-1)
}

type (
	level int
)

const (
	levelFatal level = iota + 1
	levelError
	levelWarning
	levelInfo
	levelDebug
)