Bookings_controller.rb

class BookingsController < ApplicationController
  before_action :find_parking_spot
  def index
    @bookings =  Booking.all
  end

  def new
    @booking = Booking.new
  end


  def create
    @booking = @parking_spot.bookings.build(booking_params)
    @booking.save
    flash[:notice] = 'Booking created successfully'
    #redirect to user booking show
    redirect_to parking_spot_bookings_path
  end

  def total_price
    total_price = find_parking_spot.price
  end

  private

  def find_parking_spot
    @parking_spot = ParkingSpot.find(params[:parking_spot_id])
  end

  def booking_params
    params.require(:booking).permit(:start_at, :end_at, total_price: total_price).merge(user: current_user)
  end
end

new.rb

<h1>Book Now</h1>
<h2><%= @parking_spot.street_address %></h2>

<p> the price is <%= @booking.total_price %> </p>


<%= simple_form_for [@parking_spot, @booking] do |f| %>
    <%= f.input :start_at %>
    <%= f.input :end_at %>
    <%= f.submit %>
<% end %>