package utils

import (
	"errors"
	"net/http"
)

var allowedTypes = map[string]bool{
	"image/jpeg": true,
	"image/jpg":  true,
	"image/png":  true,
	"image/gif":  true,
	"image/webp": true,
	"image/bmp":  true,
}

func IsImageMime(data string) bool {
	return allowedTypes[data]
}

func GetImageMimeType(data []byte) (string, error) {
	content_type := http.DetectContentType(data)

	if !IsImageMime(content_type) {
		return "", errors.New("Unexpected image format.")
	}

	return content_type, nil
}