Signup steps with validation

app/controllers/signup_controller.rb

@@ -2,6 +2,7 @@ class SignupController < ApplicationController
   before_action :require_user_signed_out
   before_action :require_invitation
   before_action :set_invitation
+  before_action :set_new_user, only: ["steps", "validate"]
 
   layout "signup"
 
@@ -9,8 +10,61 @@ class SignupController < ApplicationController
     @invited_by_name = @invitation.user.address
   end
 
+  def steps
+    @step = params[:step].to_i
+    http_status :not_found unless [1,2,3].include?(@step)
+    @validation_error = session[:validation_error]
+  end
+
+  def validate
+    session[:validation_error] = nil
+
+    case user_params.keys.first
+    when "cn"
+      @user.cn = user_params[:cn]
+      @user.valid?
+      session[:new_user] = @user
+
+      if @user.errors[:cn].present?
+        session[:validation_error] = @user.errors[:cn].first # Store user including validation errors
+        redirect_to signup_steps_path(1) and return
+      else
+        redirect_to signup_steps_path(2) and return
+      end
+    when "email"
+      @user.email = user_params[:email]
+      @user.valid?
+      session[:new_user] = @user
+
+      if @user.errors[:email].present?
+        session[:validation_error] = @user.errors[:email].first # Store user including validation errors
+        redirect_to signup_steps_path(2) and return
+      else
+        redirect_to signup_steps_path(3) and return
+      end
+    when "password"
+      @user.password = user_params[:password]
+      @user.password_confirmation = user_params[:password]
+      @user.valid?
+      session[:new_user] = @user
+
+      if @user.errors[:password].present?
+        session[:validation_error] = @user.errors[:password].first # Store user including validation errors
+        redirect_to signup_steps_path(3) and return
+      else
+        complete_signup
+        msg = "Almost done! We have sent you an email to confirm your address."
+        redirect_to(check_your_email_path, notice: msg) and return
+      end
+    end
+  end
+
   private
 
+  def user_params
+    params.require(:user).permit(:cn, :email, :password)
+  end
+
   def require_invitation
     if session[:invitation_token].blank?
       flash.now[:alert] = "You need an invitation to sign up for an account."
@@ -30,4 +84,27 @@ class SignupController < ApplicationController
   def set_invitation
     @invitation = Invitation.find_by(token: session[:invitation_token])
   end
+
+  def set_new_user
+    if session[:new_user].present?
+      @user = User.new(session[:new_user])
+    else
+      @user = User.new(ou: "kosmos.org")
+    end
+  end
+
+  def complete_signup
+    @user.save!
+    session[:new_user] = nil
+    session[:validation_error] = nil
+
+    CreateAccount.call(
+      username: @user.cn,
+      email: @user.email,
+      password: @user.password
+    )
+
+    @invitation.update_attributes invited_user_id: @user.id,
+      used_at: DateTime.now
+  end
 end