refactor(anti-spam): make anti-spam agnostic from Akismet

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/anti_spam/akismet.ex

@@ -1,4 +1,4 @@
-defmodule Mobilizon.Service.Akismet do
+defmodule Mobilizon.Service.AntiSpam.Akismet do
   @moduledoc """
   Validate user data
   """
@@ -9,12 +9,16 @@ defmodule Mobilizon.Service.Akismet do
   alias Mobilizon.Discussions.Comment
   alias Mobilizon.Events.Event
   alias Mobilizon.Reports.Report
+  alias Mobilizon.Service.AntiSpam.Provider
   alias Mobilizon.Users.User
   alias Mobilizon.Web.Endpoint
   require Logger
 
+  @behaviour Provider
+
   @env Application.compile_env(:mobilizon, :env)
 
+  @impl Provider
   @spec check_user(String.t(), String.t(), String.t()) ::
           :ham | :spam | :discard | {:error, HTTPoison.Response.t()}
   def check_user(email, ip, user_agent) do
@@ -27,6 +31,7 @@ defmodule Mobilizon.Service.Akismet do
     })
   end
 
+  @impl Provider
   @spec check_profile(String.t(), String.t(), String.t() | nil, String.t(), String.t()) ::
           :ham | :spam | :discard | {:error, HTTPoison.Response.t()}
   def check_profile(username, summary, email \\ nil, ip \\ "127.0.0.1", user_agent \\ nil) do
@@ -41,6 +46,7 @@ defmodule Mobilizon.Service.Akismet do
     })
   end
 
+  @impl Provider
   @spec check_event(String.t(), String.t(), String.t() | nil, String.t(), String.t()) ::
           :ham | :spam | :discard | {:error, HTTPoison.Response.t()}
   def check_event(event_body, username, email \\ nil, ip \\ "127.0.0.1", user_agent \\ nil) do
@@ -55,6 +61,7 @@ defmodule Mobilizon.Service.Akismet do
     })
   end
 
+  @impl Provider
   @spec check_comment(String.t(), String.t(), boolean(), String.t() | nil, String.t(), String.t()) ::
           :ham | :spam | :discard | {:error, HTTPoison.Response.t()}
   def check_comment(
@@ -108,6 +115,7 @@ defmodule Mobilizon.Service.Akismet do
     Application.get_env(:mobilizon, __MODULE__) |> get_in([:key])
   end
 
+  @impl Provider
   def ready?, do: !is_nil(api_key())
 
   @spec report_to_akismet_comment(Report.t()) :: AkismetComment.t() | {:error, atom()}

lib/service/anti_spam/anti_spam.ex

@@ -0,0 +1,17 @@
+defmodule Mobilizon.Service.AntiSpam do
+  @moduledoc """
+  Module to load the service adapter defined inside the configuration.
+
+  See `Mobilizon.Service.AntiSpam.Provider`.
+  """
+
+  @doc """
+  Returns the appropriate service adapter.
+
+  According to the config behind
+    `config :mobilizon, Mobilizon.Service.AntiSpam,
+       service: Mobilizon.Service.AntiSpam.Module`
+  """
+  @spec service :: module
+  def service, do: get_in(Application.get_env(:mobilizon, __MODULE__), [:service])
+end

lib/service/anti_spam/provider.ex

@@ -0,0 +1,58 @@
+defmodule Mobilizon.Service.AntiSpam.Provider do
+  @moduledoc """
+  Provider Behaviour for anti-spam detection.
+
+  ## Supported backends
+
+    * `Mobilizon.Service.AntiSpam.Akismet` [🔗](https://akismet.com/)
+
+  """
+
+  @type spam_result :: :ham | :spam | :discard
+  @type result :: spam_result() | {:error, any()}
+
+  @doc """
+  Make sure the provider is ready
+  """
+  @callback ready?() :: boolean()
+
+  @doc """
+  Check an user details
+  """
+  @callback check_user(email :: String.t(), ip :: String.t(), user_agent :: String.t()) ::
+              result()
+
+  @doc """
+  Check a profile details
+  """
+  @callback check_profile(
+              username :: String.t(),
+              summary :: String.t(),
+              email :: String.t() | nil,
+              ip :: String.t(),
+              user_agent :: String.t() | nil
+            ) :: result()
+
+  @doc """
+  Check an event details
+  """
+  @callback check_event(
+              event_body :: String.t(),
+              username :: String.t(),
+              email :: String.t() | nil,
+              ip :: String.t(),
+              user_agent :: String.t() | nil
+            ) :: result()
+
+  @doc """
+  Check a comment details
+  """
+  @callback check_comment(
+              comment_body :: String.t(),
+              username :: String.t(),
+              is_reply? :: boolean(),
+              email :: String.t() | nil,
+              ip :: String.t(),
+              user_agent :: String.t() | nil
+            ) :: result()
+end