dmails: factor out spam detector service.

app/logical/spam_detector.rb

@@ -0,0 +1,44 @@
+# https://github.com/joshfrench/rakismet
+# https://akismet.com/development/api/#comment-check
+
+class SpamDetector
+  include Rakismet::Model
+
+  attr_accessor :user, :user_ip, :content, :comment_type
+  rakismet_attrs author: proc { user.name },
+                 author_email: proc { user.email },
+                 blog_lang: "en",
+                 blog_charset: "UTF-8",
+                 comment_type: :comment_type,
+                 content: :content,
+                 user_ip: :user_ip
+
+  def self.enabled?
+    Danbooru.config.rakismet_key.present? && Danbooru.config.rakismet_url.present? && !Rails.env.test?
+  end
+
+  # rakismet raises an exception if the api key or url aren't configured
+  def self.working?
+    Rakismet.validate_key
+  rescue
+    false
+  end
+
+  def initialize(record)
+    case record
+    when Dmail
+      @user = record.from
+      @content = record.body
+      @comment_type = "message"
+      @user_ip = record.creator_ip_addr.to_s
+    else
+      raise ArgumentError
+    end
+  end
+
+  def spam?
+    return false if !SpamDetector.enabled?
+    return false if user.is_gold?
+    super
+  end
+end