osem/app/controllers/payments_controller.rb

class PaymentsController < ApplicationController
  before_action :authenticate_user!
  load_and_authorize_resource
  load_resource :conference, find_by: :short_title
  authorize_resource :conference_registrations, class: Registration

  def index
    @payments = current_user.payments
  end

  def new
    @total_amount_to_pay = Ticket.total_price(@conference, current_user, paid: false)
    @unpaid_ticket_purchases = current_user.ticket_purchases.unpaid.by_conference(@conference)
  end

  def create
    @payment = Payment.new payment_params

    if @payment.purchase && @payment.save
      update_purchased_ticket_purchases
      redirect_to conference_conference_registration_path(@conference.short_title),
                  notice: 'Thanks! Your ticket is booked successfully.'
    else
      @total_amount_to_pay = Ticket.total_price(@conference, current_user, paid: false)
      @unpaid_ticket_purchases = current_user.ticket_purchases.unpaid.by_conference(@conference)
      flash[:error] = @payment.errors.full_messages.to_sentence + ' Please try again with correct credentials.'
      render :new
    end
  end

  private

  def payment_params
    params.permit(:stripe_customer_email, :stripe_customer_token)
          .merge(stripe_customer_email: params[:stripeEmail],
                 stripe_customer_token: params[:stripeToken],
                 user: current_user, conference: @conference)
  end

  def update_purchased_ticket_purchases
    current_user.ticket_purchases.by_conference(@conference).unpaid.update_all(paid: true, payment_id: @payment.id)
  end
end