From 06ff249530ca644de6c7d479833dcf7ff9ef374f Mon Sep 17 00:00:00 2001
From: evazion <noizave@gmail.com>
Date: Fri, 23 Aug 2019 18:59:28 -0500
Subject: [PATCH] dmails: factor out spam detector service.

---
 app/controllers/dmails_controller.rb |  2 --
 app/logical/spam_detector.rb         | 44 ++++++++++++++++++++++++++++
 app/models/dmail.rb                  |  8 +----
 config/danbooru_default_config.rb    |  1 +
 test/unit/dmail_test.rb              |  7 ++---
 test/unit/spam_detector.rb           | 31 ++++++++++++++++++++
 6 files changed, 79 insertions(+), 14 deletions(-)
 create mode 100644 app/logical/spam_detector.rb
 create mode 100644 test/unit/spam_detector.rb

diff --git a/app/controllers/dmails_controller.rb b/app/controllers/dmails_controller.rb
index 4af7d3258..38b45ecae 100644
--- a/app/controllers/dmails_controller.rb
+++ b/app/controllers/dmails_controller.rb
@@ -58,13 +58,11 @@ class DmailsController < ApplicationController
   def spam
     @dmail = Dmail.find(params[:id])
     @dmail.update_column(:is_spam, true)
-    @dmail.spam!
   end
 
   def ham
     @dmail = Dmail.find(params[:id])
     @dmail.update_column(:is_spam, false)
-    @dmail.ham!
   end
 
 private
diff --git a/app/logical/spam_detector.rb b/app/logical/spam_detector.rb
new file mode 100644
index 000000000..6ef629503
--- /dev/null
+++ b/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
diff --git a/app/models/dmail.rb b/app/models/dmail.rb
index b5934ef23..f5c0cdb17 100644
--- a/app/models/dmail.rb
+++ b/app/models/dmail.rb
@@ -6,8 +6,6 @@ class Dmail < ApplicationRecord
   AUTOBAN_WINDOW = 24.hours
   AUTOBAN_DURATION = 3
 
-  include Rakismet::Model
-
   validates_presence_of :title, :body, on: :create
   validate :validate_sender_is_not_banned, on: :create
 
@@ -20,8 +18,6 @@ class Dmail < ApplicationRecord
   after_create :update_recipient
   after_commit :send_email, on: :create
 
-  rakismet_attrs author: proc { from.name }, author_email: proc { from.email }, content: proc { title + "\n\n" + body }, user_ip: proc { creator_ip_addr.to_s }
-
   concerning :SpamMethods do
     class_methods do
       def is_spammer?(user)
@@ -41,9 +37,7 @@ class Dmail < ApplicationRecord
     end
 
     def spam?
-      return false if Danbooru.config.rakismet_key.blank?
-      return false if from.is_gold?
-      super()
+      SpamDetector.new(self).spam?
     end
   end
 
diff --git a/config/danbooru_default_config.rb b/config/danbooru_default_config.rb
index 026ed3dfe..537e467b0 100644
--- a/config/danbooru_default_config.rb
+++ b/config/danbooru_default_config.rb
@@ -762,6 +762,7 @@ module Danbooru
     end
 
     def rakismet_url
+      "https://#{hostname}"
     end
 
     # Cloudflare data
diff --git a/test/unit/dmail_test.rb b/test/unit/dmail_test.rb
index a84277668..c6ed3ee8d 100644
--- a/test/unit/dmail_test.rb
+++ b/test/unit/dmail_test.rb
@@ -17,11 +17,8 @@ class DmailTest < ActiveSupport::TestCase
 
     context "spam" do
       setup do
-        Dmail.any_instance.stubs(:spam?).returns(true) unless Danbooru.config.rakismet_key.present?
-
-        # viagra-test-123 is guaranteed to be flagged as spam.
-        # https://akismet.com/development/api/#detailed-docs
-        @spammer = create(:user, name: "viagra-test-123")
+        Dmail.any_instance.stubs(:spam?).returns(true)
+        @spammer = create(:user)
         @recipient = create(:user)
       end
 
diff --git a/test/unit/spam_detector.rb b/test/unit/spam_detector.rb
new file mode 100644
index 000000000..516c64c35
--- /dev/null
+++ b/test/unit/spam_detector.rb
@@ -0,0 +1,31 @@
+require "test_helper"
+
+class SpamDetectorTest < ActiveSupport::TestCase
+  context "SpamDetector" do
+    setup do
+      skip "SpamDetector not working: API key not configured, not valid, or akismet is down" if !SpamDetector.working?
+      SpamDetector.stubs(:enabled?).returns(true)
+
+      @user = create(:gold_user)
+      @spammer = create(:user, email: "akismet-guaranteed-spam@example.com")
+    end
+
+    context "for dmails" do
+      should "detect spam" do
+        Dmail.create_split(from: @spammer, to: @user, title: "spam", body: "wonderful spam", creator_ip_addr: "127.0.0.1")
+
+        dmail = @user.dmails.last
+        assert(SpamDetector.new(dmail).spam?)
+        assert(dmail.is_spam?)
+      end
+
+      should "not detect gold users as spammers" do
+        Dmail.create_split(from: @user, to: @spammer, title: "spam", body: "wonderful spam", creator_ip_addr: "127.0.0.1")
+
+        dmail = @spammer.dmails.last
+        refute(SpamDetector.new(dmail).spam?)
+        refute(dmail.is_spam?)
+      end
+    end
+  end
+end