package logger

import (
	"errors"
	"fmt"
	"os"
	"time"
)

var outfile *os.File
var outfileB *os.File

var lastWasReturn = false

var ErrCantConfigLog = errors.New("cannot configure log")

func Config(path string) error {
	if path == "" {
		return nil
	}
	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
	if err != nil {
		return ErrCantConfigLog
	}
	outfile = f
	return nil
}

func Logf(args ...interface{}) {
	if outfile == nil {
		outfile = os.Stderr
	}
	defer outfile.Sync()
	if len(args) == 0 {
		fmt.Fprintln(outfile, "")
		return
	}
	v := fmt.Sprintf(args[0].(string), args[1:]...)
	if v[len(v)-1] == '\n' {
		v = v[:len(v)-1]
	}
	thisWasReturn := v[0] == '\r'
	if lastWasReturn && !thisWasReturn {
		fmt.Println()
	}
	if thisWasReturn {
		fmt.Fprintf(outfile, "\r%s%v", prefix(), v[1:])
	} else {
		fmt.Fprintf(outfile, "%s%v\n", prefix(), v)
	}
	lastWasReturn = thisWasReturn
}

func Fatalf(args ...interface{}) {
	Logf(args...)
	if len(args) > 0 {
		panic(args[0])
	} else {
		panic("Panic from logger.fatal()")
	}
}

func Fatal(args ...interface{}) {
	Log(args...)
	if len(args) > 0 {
		panic(args[0])
	} else {
		panic("Panic from logger.fatal()")
	}
}

func Log(args ...interface{}) {
	if lastWasReturn {
		fmt.Println()
	}
	if outfile == nil {
		outfile = os.Stderr
	}
	v := fmt.Sprintf("%v", args)
	v = v[1 : len(v)-1]
	fmt.Fprintf(outfile, "%s%v\n", prefix(), v)
	outfile.Sync()
	lastWasReturn = false
}

func LogB(args ...interface{}) {
	if outfileB == nil {
		outfileB = os.Stderr
	}
	v := fmt.Sprintf("%v", args)
	v = v[1 : len(v)-1]
	fmt.Fprintf(outfileB, "%s%v\n", prefix(), v)
	outfileB.Sync()
}

func prefix() string {
	return time.Now().Format("20060102-150405") + " : "
}