package utils

import (
	"fmt"
	"math/rand"
	"os"
	"path"
	"strconv"
	"strings"
	"time"

	"github.com/OpenIMSDK/Open-IM-Server/pkg/common/constant"
)

const (
	BYTE = 1 << (10 * iota)
	KILOBYTE
	MEGABYTE
	GIGABYTE
	TERABYTE
	PETABYTE
	EXABYTE
)

// Determine whether the given path is a folder
func IsDir(path string) bool {
	s, err := os.Stat(path)
	if err != nil {
		return false
	}
	return s.IsDir()
}

// Determine whether the given path is a file
func IsFile(path string) bool {
	return !IsDir(path)
}

// Create a directory
func MkDir(path string) error {
	return os.MkdirAll(path, os.ModePerm)
}

func GetNewFileNameAndContentType(fileName string, fileType int) (string, string) {
	suffix := path.Ext(fileName)
	newName := fmt.Sprintf("%d-%d%s", time.Now().UnixNano(), rand.Int(), fileName)
	contentType := ""
	if fileType == constant.ImageType {
		contentType = "image/" + suffix[1:]
	}
	return newName, contentType
}

func ByteSize(bytes uint64) string {
	unit := ""
	value := float64(bytes)
	switch {
	case bytes >= EXABYTE:
		unit = "E"
		value = value / EXABYTE
	case bytes >= PETABYTE:
		unit = "P"
		value = value / PETABYTE
	case bytes >= TERABYTE:
		unit = "T"
		value = value / TERABYTE
	case bytes >= GIGABYTE:
		unit = "G"
		value = value / GIGABYTE
	case bytes >= MEGABYTE:
		unit = "M"
		value = value / MEGABYTE
	case bytes >= KILOBYTE:
		unit = "K"
		value = value / KILOBYTE
	case bytes >= BYTE:
		unit = "B"
	case bytes == 0:
		return "0"
	}
	result := strconv.FormatFloat(value, 'f', 1, 64)
	result = strings.TrimSuffix(result, ".0")
	return result + unit
}