Refactor petition creation

Remove the stage manager class and replace it with a simpler
form/service object based on Active Model. This allows us to
flatten the parameter hash and control when and what is
validated much easier than using the Active Record classes.

app/controllers/petitions_controller.rb

@@ -1,8 +1,6 @@
 require 'csv'
 
 class PetitionsController < ApplicationController
-  include ManagingMoveParameter
-
   before_action :redirect_to_valid_state, only: [:index]
   before_action :do_not_cache, except: [:index, :show]
 
@@ -12,6 +10,8 @@ class PetitionsController < ApplicationController
 
   before_action :retrieve_petitions, only: [:index]
   before_action :retrieve_petition, only: [:show, :count, :gathering_support, :moderation_info]
+  before_action :build_petition_creator, only: [:check, :check_results, :new, :create]
+
   before_action :redirect_to_stopped_page, if: :stopped?, only: [:moderation_info, :show]
   before_action :redirect_to_gathering_support_url, if: :collecting_sponsors?, only: [:moderation_info, :show]
   before_action :redirect_to_moderation_info_url, if: :in_moderation?, only: [:gathering_support, :show]
@@ -41,41 +41,31 @@ def count
     end
   end
 
-  def new
-    assign_action
-    assign_stage
-    @stage_manager = Staged::PetitionCreator.manager(petition_params_for_new, request, params[:stage], params[:move])
-
+  def check
     respond_to do |format|
       format.html
     end
   end
 
-  def create
-    assign_move
-    assign_stage
-    @stage_manager = Staged::PetitionCreator.manager(petition_params_for_create, request, params[:stage], params[:move])
-    if @stage_manager.create_petition
-      @stage_manager.petition.creator.store_constituency_id
-      send_email_to_gather_sponsors(@stage_manager.petition)
-      redirect_to thank_you_petition_url(@stage_manager.petition)
-    else
-      respond_to do |format|
-        format.html { render :new }
-      end
+  def check_results
+    respond_to do |format|
+      format.html
     end
   end
 
-  def check
+  def new
     respond_to do |format|
       format.html
     end
   end
 
-  def check_results
-    @petitions = Petition.current.search(params.merge(count: 3))
-    respond_to do |format|
-      format.html
+  def create
+    if @new_petition.save
+      redirect_to thank_you_petition_url(@new_petition)
+    else
+      respond_to do |format|
+        format.html { render :new }
+      end
     end
   end
 
@@ -119,6 +109,10 @@ def retrieve_petition
     @petition = Petition.show.find(petition_id)
   end
 
+  def build_petition_creator
+    @new_petition = PetitionCreator.new(params, request)
+  end
+
   def redirect_to_valid_state
     if state_present? && !valid_state?
       redirect_to petitions_url(search_params(state: :all))
@@ -169,42 +163,6 @@ def redirect_to_petition_url
     redirect_to petition_url(@petition)
   end
 
-  def petition_params_for_new
-    params.
-      fetch('petition', {}).
-      permit(:action)
-  end
-
-  def petition_params_for_create
-    params.
-      require(:petition).
-      permit(:action, :background, :additional_details, :duration,
-             creator: [
-               :name, :email, :email_confirmation,
-               :postcode, :location_code, :uk_citizenship
-             ]).tap do |sanitized|
-               if sanitized['creator'].present?
-                 sanitized['creator_attributes'] = sanitized.delete('creator')
-               end
-             end
-  end
-
-  def assign_action
-    return if params[:petition_action].blank?
-    petition_action = params.delete(:petition_action)
-    params[:petition] ||= {}
-    params[:petition][:action] = petition_action
-  end
-
-  def assign_stage
-    return if Staged::PetitionCreator.stages.include? params[:stage]
-    params[:stage] = 'petition'
-  end
-
-  def send_email_to_gather_sponsors(petition)
-    GatherSponsorsForPetitionEmailJob.perform_later(petition)
-  end
-
   def csv_filename
     "#{@petitions.scope}-petitions.csv"
   end

app/helpers/petition_helper.rb

@@ -1,11 +1,4 @@
 module PetitionHelper
-  def render_petition_form(stage_manager, form)
-    capture do
-      concat render_petition_hidden_details(stage_manager, form)
-      concat render_petition_ui(stage_manager, form)
-    end
-  end
-
   def public_petition_facets_with_counts(petition_search)
     petition_search.facets.slice(*public_petition_facets)
   end
@@ -40,33 +33,4 @@ def petition_list_header?
   def reveal_government_response?
     params[:reveal_response] == "yes"
   end
-
-  private
-
-  def render_petition_hidden_details(stage_manager, form)
-    capture do
-      concat hidden_field_tag(:stage, stage_manager.stage)
-      concat hidden_field_tag(:move, 'next')
-      concat render('/petitions/create/petition_details_hidden', petition: stage_manager.stage_object, f: form) unless stage_manager.stage == 'petition'
-      if stage_manager.stage_object.creator.present?
-        concat render('/petitions/create/your_details_hidden', petition: stage_manager.stage_object, f: form) unless stage_manager.stage == 'creator'
-        concat render('/petitions/create/email_hidden', petition: stage_manager.stage_object, f: form) unless ['creator', 'replay-email'].include? stage_manager.stage
-      end
-    end
-  end
-
-  def render_petition_ui(stage_manager, form)
-    # NOTE: make sure we skip past the existing tabindex-ed elements on the page, no matter which ui we render
-    increment(4)
-    case stage_manager.stage
-    when 'petition'
-      render('/petitions/create/petition_details_ui', petition: stage_manager.stage_object, f: form)
-    when 'creator'
-      render('/petitions/create/your_details_ui', petition: stage_manager.stage_object, f: form)
-    when 'replay-petition'
-      render('/petitions/create/replay_petition_ui', petition: stage_manager.stage_object, f: form)
-    when 'replay-email'
-      render('/petitions/create/replay_email_ui', petition: stage_manager.stage_object, f: form)
-    end
-  end
 end