defmodule ExKits.Crypto.Common do
  @moduledoc false
  @doc """
  md5
  """
  @spec md5(String.t()) :: binary()
  def md5(plaintext), do: :crypto.hash(:md5, plaintext)

  @doc """
  sha1
  """
  @spec sha(String.t()) :: binary()
  def sha(plaintext), do: :crypto.hash(:sha, plaintext)

  @doc """
  sha256
  """
  @spec sha256(String.t()) :: binary()
  def sha256(plaintext), do: :crypto.hash(:sha256, plaintext)

  @doc """
  generate random string
  ## Example

  iex(17)> Common.Crypto.random_string 16
  "2jqDlUxDuOt-qyyZ"
  """
  @spec random_string(integer()) :: String.t()
  def random_string(length) do
    length
    |> :crypto.strong_rand_bytes()
    |> Base.url_encode64()
    |> binary_part(0, length)
  end
end