common controller from markee.ru

common_controller.rb

class Frontend::CommonController < ApplicationController

  before_action :set_ig_user, except: [:auth, :login, :logout]
  before_action :create_cart

  # Set custom layout
  layout 'frontend'

  def index
    @catalog_items = CatalogueItem.published.to_a
  end

  def info
    @deliveries = Delivery.published.order(price: :asc).to_a
    @payments   = Payment.published.to_a
  end

  def auth
    redirect_uri = IG_CALLBACK_URL
    # provide back url if passed somewhere
    redirect_uri += "?back_url=#{params[:back_url]}" if params[:back_url].present?

    ig_response = Instagram.get_access_token(params[:code], :redirect_uri => redirect_uri)
    session[:ig_access_token] = ig_response.access_token
    cookies[:ig_access_token] = {value: session[:ig_access_token], expires: 30.days.from_now}

    #redirect to back_url or root
    if params[:back_url].present?
      redirect_to params[:back_url]
    else
      redirect_to root_path
    end
  end

  def login
    if session[:ig_access_token].nil?
      ig_authenticate_user!
    else
      redirect_to root_path
    end
  end

  def logout
    session.delete :ig_user_id
    session.delete :ig_access_token if session[:ig_access_token].present?
    cookies.delete :cart_id if cookies[:cart_id].present?
    cookies.delete :ig_access_token if cookies[:ig_access_token].present?
    redirect_to root_path
  end

  private

    def ig_authenticate_user!
      # authorize on instagram if not yet authorized
      if session[:ig_access_token].nil?
        return redirect_to Instagram.authorize_url(:redirect_uri => IG_CALLBACK_URL) 
      end

      @ig_user = Instagram.client(:access_token => session[:ig_access_token])
    end

    def set_ig_user
      access_token = session[:ig_access_token] || cookies[:ig_access_token]

      if access_token.nil?
        @ig_user = nil
      else
        @ig_user = Instagram.client(:access_token => access_token)
        
        # fetch instagram user info
        begin
          @current_user = @ig_user.user
          # set user_id for future uses
          session[:ig_user_id] = @current_user.id unless session[:id_user_id].present?
        rescue Instagram::BadRequest => e
          # if we have message 'invalid access_token' then re-authorize user
          if e.message.match(/access_token/)
            return redirect_to Instagram.authorize_url(:redirect_uri => IG_CALLBACK_URL) 
          end
        end
      end
    end

    def create_cart
      if session[:ig_user_id].present?
        @cart = Cart.find_or_create_by(ig_user_id: session[:ig_user_id])
      else
        @cart = Cart.find_or_create_by(id: session[:cart_id])

        session[:cart_id] = @cart.id unless session[:cart_id].present?
      end
    end

end