package gravatar import ( "crypto/md5" "fmt" "strings" ) const baseUrl = "https://www.gravatar.com/avatar" const defaultSize = 80 const maxSize = 2048 func Url(email string, size int) string { email = strings.ToLower(email) email = strings.TrimSpace(email) hash := md5.Sum([]byte(email)) if size < 1 { size = defaultSize } size = min(maxSize, size) return fmt.Sprintf("%s/%x?s=%d", baseUrl, hash, size) }