Zoho Invoide Service using Oauth

zoho_invoice_service.rb

require 'oauth2'
require 'json'

module ZohoServices
  class Invoice
    attr_reader :oauth_auth_code, :client

    def initialize
      @customer_id = "CUSTOMER_ID" # define this customer_id
      @query_root = "https://invoice.zoho.com/api/v3"
      @organization_id = "ORGANIZATION_ID" # define this organization_id
      @client = OAuth2::Client.new("CLIENT_ID", "CLIENT_SECRET", {
        :site => 'https://accounts.zoho.com', authorize_url: 'oauth/v2/auth', token_url: 'oauth/v2/token'
      })
      @redirect_url = 'https://example.com/oauth2callback'
    end

    def get_authorize_url
      url = @client.auth_code.authorize_url({
        :scope => 'ZohoInvoice.invoices.CREATE,ZohoInvoice.invoices.READ,ZohoInvoice.invoices.UPDATE,ZohoInvoice.invoices.DELETE',
        :redirect_uri => @redirect_url,
        :access_type => 'offline'
      })
      url #copy this url into browser
    end

    def set_access_token(code=nil)
      @access_token = @client.auth_code.get_token(code || @oauth_auth_code,
        {:redirect_uri => @redirect_url})
      @serialized_access_token = @access_token.to_hash.to_json
      
      # save access token
      your_model.update_columns({
        zoho_access_token: JSON.parse(@serialized_access_token)['access_token'],
        zoho_expires_at: Time.now + JSON.parse(@serialized_access_token)['expires_in_sec'].to_i.seconds
      })
      your_model.zoho_refresh_token = JSON.parse(@serialized_access_token)['refresh_token'] if JSON.parse(@serialized_access_token)['refresh_token'].present?
      your_model.save
      nil
    end


    def get(query, opts = {})
      refresh_access_token if expired?
      response_json = @access_token.get("#{@query_root}/#{query}", opts).body
      JSON.parse(response_json)
    end

    def post(query, opts = {})
      refresh_access_token if expired?
      response_json = @access_token.post("#{@query_root}/#{query}", opts).body
      JSON.parse(response_json)
    end

    def put(query, opts = {})
      response_json = @access_token.put("#{@query_root}/#{query}", opts).body
      JSON.parse(response_json)
    end

    def restore_access_token
      @access_token = OAuth2::AccessToken.from_hash @client,
      {
        :refresh_token => your_model.zoho_refresh_token,
        :access_token => your_model.zoho_access_token,
        :expires_at => your_model.zoho_expires_at
      }
      nil
    end

    def expired?
      restore_access_token unless @access_token
      @access_token.expired?
    end

    def access_token_object
      restore_access_token unless @access_token
      @access_token
    end

    def access_token
      restore_access_token unless @access_token
      @access_token.token
    end

    def refresh_token
      restore_access_token unless @access_token
      @access_token.refresh_token
    end

    def refresh_access_token
      restore_access_token unless @access_token
      @access_token = @access_token.refresh!
      @serialized_access_token = @access_token.to_hash.to_json
      your_model.update_columns({
        zoho_access_token: JSON.parse(@serialized_access_token)['access_token'],
        zoho_expires_at: Time.now + JSON.parse(@serialized_access_token)['expires_in_sec'].to_i.seconds
      })
      your_model.zoho_refresh_token = JSON.parse(@serialized_access_token)['refresh_token'] if JSON.parse(@serialized_access_token)['refresh_token'].present?
      your_model.save
      nil
    end

    def invoices
      get('invoices')["invoices"]
    end

    def find(invoice_id)
      get("invoices/#{invoice_id}")
    end

    def find_by_reference_number(reference_number)
      results = get("invoices?search_text=#{reference_number}")
      results["invoices"].first
    end

    def create_invoice(order)
      return false unless reservation
      # specify fields to send here, reference https://www.zoho.com/invoice/api/v3/#Invoices_Create_an_invoice
      body = {
        "JSONString" => {
          customer_id: @customer_id,
          reference_number: order.id,
          line_items: [
              name: order.name,
              rate: order.total,
              quantity: 1
            ]
          }.to_json
        }
      post("invoices", {body: body})
    end
  end
end