GRN2-155: Begin preparing for removal of Twitter accounts (#615)

* Add twitter deprecation message

* Fix rspec test

* Extract room switch to its own method

* update method name

app/controllers/sessions_controller.rb

@@ -51,6 +51,10 @@ class SessionsController < ApplicationController
       @auth = request.env['omniauth.auth']
       @user_exists = check_user_exists
 
+      if !@user_exists && @auth['provider'] == "twitter"
+        return redirect_to root_path, flash: { alert: I18n.t("registration.deprecated.twitter_signup") }
+      end
+
       # If using invitation registration method, make sure user is invited
       return redirect_to root_path, flash: { alert: I18n.t("registration.invite.no_invite") } unless passes_invite_reqs
 
@@ -70,6 +74,16 @@ class SessionsController < ApplicationController
                                              invite_registration && !@user_exists
 
       login(user)
+
+      if @auth['provider'] == "twitter"
+        flash[:alert] = if allow_user_signup? && allow_greenlight_accounts?
+                          I18n.t("registration.deprecated.twitter_signin",
+                            link: signup_path(old_twitter_user_id: user.id))
+                        else
+                          I18n.t("registration.deprecated.twitter_signin",
+                            link: signin_path(old_twitter_user_id: user.id))
+                        end
+      end
     rescue => e
         logger.error "Error authenticating via omniauth: #{e}"
         omniauth_fail

app/controllers/users_controller.rb

@@ -62,6 +62,10 @@ class UsersController < ApplicationController
 
   # GET /signin
   def signin
+    unless params[:old_twitter_user_id].nil? && session[:old_twitter_user_id].nil?
+      flash[:alert] = I18n.t("registration.deprecated.new_signin")
+      session[:old_twitter_user_id] = params[:old_twitter_user_id] unless params[:old_twitter_user_id].nil?
+    end
   end
 
   # GET /signup
@@ -75,6 +79,12 @@ class UsersController < ApplicationController
       session[:invite_token] = params[:invite_token]
     end
 
+    unless params[:old_twitter_user_id].nil? && session[:old_twitter_user_id].nil?
+      logout
+      flash.now[:alert] = I18n.t("registration.deprecated.new_signin")
+      session[:old_twitter_user_id] = params[:old_twitter_user_id] unless params[:old_twitter_user_id].nil?
+    end
+
     @user = User.new
   end
 
@@ -175,7 +185,7 @@ class UsersController < ApplicationController
   end
 
   def ensure_unauthenticated
-    redirect_to current_user.main_room if current_user
+    redirect_to current_user.main_room if current_user && params[:old_twitter_user_id].nil?
   end
 
   def user_params