defmodule Bamboo.Interceptor do
  @moduledoc ~S"""
  Behaviour for creating an Interceptor.

  An interceptor allows you to modify or block an email before it is sent. To
  block an email, it must be marked as blocked with `Bamboo.Email.block/1`.

  ## Example

      defmodule Bamboo.DenyListInterceptor do
        @behaviour Bamboo.Interceptor
        @deny_list ["bar@foo.com"]

        def call(email) do
          if email.to in @deny_list do
            Bamboo.Email.block(email)
          else
            email
          end
        end
      end
  """

  @callback call(email :: Bamboo.Email.t()) :: Bamboo.Email.t()
end