Rubocop and handle exceptions correctly

-require "bundler/gem_tasks"
+require 'bundler/gem_tasks'

 #!/usr/bin/env ruby
 
-require "bundler/setup"
-require "var"
+require 'bundler/setup'
+require 'var'
 
 # You can add fixtures and/or initialization code here to make experimenting
 # with your gem easier. You can also use a different console, if you like.
@@ -10,5 +10,5 @@ require "var"
 # require "pry"
 # Pry.start
 
-require "irb"
+require 'irb'
 IRB.start

 class AddVarStatusTo<%=@model_name.pluralize.camelize%> < ActiveRecord::Migration
   def change
     add_column :<%=@model_name.pluralize.underscore%>, :var_status, :string, default: 'pending'
-    add_column :<%=@model_name.pluralize.underscore%>, :barcode_url, :string
+    add_column :<%=@model_name.pluralize.underscore%>, :var_barcode_url, :string
+    add_column :<%=@model_name.pluralize.underscore%>, :var_barcode, :string
+    add_column :<%=@model_name.pluralize.underscore%>, :var_payment_expires_at, :datetime
+    add_column :<%=@model_name.pluralize.underscore%>, :var_id, :string
+    add_column :<%=@model_name.pluralize.underscore%>, :var_service, :string
   end
 end

 require 'rails/generators'
-
+# Generator for models
 class VarModelGenerator < Rails::Generators::NamedBase
   source_root File.expand_path('../templates', __FILE__)
-  desc "This generator generates layout file with navigation."
+  desc 'This generator generates layout file with navigation.'
 
   def generate_model
     d = Time.now.strftime('%Y%m%d%H%M%S')
     @model_name = name
-    template "var_model.rb",
-    				 "db/migrate/#{d}_add_var_status_to_#{name.pluralize.underscore}.rb"
+    template 'var_model.rb',
+             "db/migrate/#{d}_add_var_status_to_#{name.pluralize.underscore}.rb"
   end
 end

-require "var/version"
+require 'var/version'
 require 'conekta'
 require 'paypal-sdk-rest'
 
+# Main Module
 module Var
   # TODO: add paypal
   # @@valid_services = [:conekta, :paypal]
@@ -13,15 +14,15 @@ module Var
 
   def self.create_charge(service, object, options = {})
     return { error_message: 'Service is not supported' } unless VALID_SERVICES.include? service
-    return { error_message: "#{object.class.to_s} doesn't support charges"} unless object.respond_to?(:charge_with)
+    return { error_message: "#{object.class} doesn't support charges" } unless object.respond_to?(:charge_with)
     charge = object.charge_with(service, options)
-    return charge
+    charge
   end
 end
-
+# Module for models
 module ActsAsChargeable
   extend ActiveSupport::Concern
-
+  # Class Methods
   module ClassMethods
     def acts_as_chargeable(keys = {})
       include ChargeableInstanceMethods
@@ -29,55 +30,62 @@ module ActsAsChargeable
       self.sync_attributes = keys
     end
   end
-
+  # Instance Methods
   module ChargeableInstanceMethods
     def charge_with(service, options)
-      if !instance_support?(service)
-        error_message = "#{self.class.to_s} doesn't support" \
-                        " charges with #{service.to_s}"
-        return { error_message: error_message}
+      unless instance_support?(service)
+        error_message = "#{self.class} doesn't support" \
+                        " charges with #{service}"
+        return { error_message: error_message }
       end
-      self.send("charge_with_#{service.to_s}", options)
-    rescue  Exception => exception
+      send("charge_with_#{service}", options)
+    rescue Exception => exception
       { error_message: exception.message }
     end
 
     def charge_with_conekta(options)
       charge = conekta_charge(options)
-      object.update_columns(var_status: charge.status)
+      update_columns(var_status: charge.status, var_id: charge.id,
+                     var_service: 'conekta')
+      update_conekta_barcode(charge) if options[:conekta_type] == 'oxxo'
       charge
-    rescue Conekta::ParameterValidationError, Conekta::ProcessingError, Conekta::Error  => e
-      self.update_columns(var_status: 'failed')
+    rescue Conekta::ParameterValidationError, Conekta::ProcessingError,
+           Conekta::Error => e
+      update_columns(var_status: 'failed')
       { error_message: e.message }
     end
 
-    def conekta_charge(conekta_type)
+    def conekta_charge(options)
       @charge ||= Conekta::Charge.create({
-        description: self.sync(:conekta, 'description'),
-        amount: self.sync(:conekta, 'amount'), currency: "MXN",
-        reference_id: self.sync(:conekta, 'reference_id'),
+        description: sync(:conekta, 'description'),
+        amount: sync(:conekta, 'amount'), currency: 'MXN',
+        reference_id: sync(:conekta, 'reference_id'),
         details: {
-          name: self.sync(:conekta, 'name'),
-          email: self.sync(:conekta, 'email'),
+          name: sync(:conekta, 'name'), email: sync(:conekta, 'email'),
           line_items: [{
-            name: self.sync(:conekta, 'name'),
-            description: self.sync(:conekta, 'description'),
-            unit_price: self.sync(:conekta, 'amount'), quantity: 1,
-          }]
-        }
+            description: sync(:conekta, 'description'), quantity: 1,
+            unit_price: sync(:conekta, 'amount'), name: sync(:conekta, 'name')
+          }] }
       }.merge(conekta_type_of_charge(options)))
     end
 
-    def conekta_type_of_charge(conekta_type)
+    def conekta_type_of_charge(options)
       if options[:conekta_type] == 'card'
         { card: options[:card_token] }
       elsif options[:conekta_type] == 'oxxo'
-        { cash: { type: "oxxo",
-                  expires_at: (Time.zone.today + 3.days).strftime('%Y-%m-%d')}
+        { cash: { type: 'oxxo',
+                  expires_at: (Time.zone.today + 3.days).strftime('%Y-%m-%d') }
         }
       end
     end
 
+    def update_conekta_barcode(charge)
+      method = charge.payment_method
+      update_columns(var_barcode: method.barcode,
+                     var_barcode_url: method.barcode_url,
+                     var_payment_expires_at: Time.at(method.expires_at))
+    end
+
     # def charge_with_paypal(options)
     #   if(!options.include? :card)
     #     error_message = "Paypal needs a card sent as a third paramater"
@@ -110,14 +118,10 @@ module ActsAsChargeable
     #       description: self.sync(:paypal, 'description') }]})
     # end
 
-    def find_charge(service)
-      if !instance_support?(service)
-        error_message = "#{self.class.to_s} doesn't support" \
-                      " charges with #{service.to_s}"
-        return { error_message: error_message}
-      end
-      self.send("find_#{service.to_s}_charge")
-    rescue  Exception => exception
+    def find_charge
+      return { error_message: 'Not charged yet' } unless var_service
+      send("find_#{var_service}_charge")
+    rescue Exception => exception
       { error_message: exception.message }
     end
 
@@ -127,18 +131,17 @@ module ActsAsChargeable
     end
 
     def find_conekta_charge
-      ref_id = self.sync(:conekta, 'reference_id')
-      Conekta::Charge.where({'status.ne'=>'paid', 'reference_id'=> ref_id})
+      Conekta::Charge.find(var_id)
     end
 
     def instance_support?(service)
-      return self.sync_attributes.include?(service)
+      sync_attributes.include?(service)
     end
 
     def sync(service, key)
-      service_attributes = self.send("#{service.to_s}_attributes")
-      return self.send(key) if !service_attributes.include? key.to_sym
-      self.send(service_attributes[key.to_sym])
+      service_attributes = send("#{service}_attributes")
+      return send(key) unless service_attributes.include? key.to_sym
+      send(service_attributes[key.to_sym])
     end
 
     # def sync_attribute(key)
@@ -147,13 +150,15 @@ module ActsAsChargeable
     # end
 
     def conekta_attributes
-      self.sync_attributes[:conekta] || {}
+      sync_attributes[:conekta] || {}
     end
 
     def paypal_attributes
-      self.sync_attributes[:paypal] || {}
+      sync_attributes[:paypal] || {}
     end
   end
 end
 
-ActiveRecord::Base.send(:include, ActsAsChargeable) if defined? ActiveRecord::Base
\ No newline at end of file
+if defined? ActiveRecord::Base
+  ActiveRecord::Base.send(:include, ActsAsChargeable)
+end

+# Var Version
 module Var
-  VERSION = "0.2.5"
+  VERSION = '0.2.8'
 end

@@ -4,30 +4,30 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'var/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "var"
+  spec.name          = 'var'
   spec.version       = Var::VERSION
-  spec.authors       = ["abrahamrq"]
-  spec.email         = ["abraham.rq03@gmail.com"]
+  spec.authors       = ['abrahamrq']
+  spec.email         = ['abraham.rq03@gmail.com']
 
-  spec.summary       = %q{summary of var}
-  spec.description   = %q{description of var}
-  spec.homepage      = "https://github.com/abrahamrq"
+  spec.summary       = 'summary of var'
+  spec.description   = 'description of var'
+  spec.homepage      = 'https://github.com/abrahamrq'
 
   # Prevent pushing this gem to RubyGems.org by setting 'allowed_push_host', or
   # delete this section to allow pushing this gem to any host.
   if spec.respond_to?(:metadata)
     spec.metadata['allowed_push_host'] = "TODO: Set to 'http://mygemserver.com'"
   else
-    raise "RubyGems 2.0 or newer is required to protect against public gem pushes."
+    fail 'RubyGems 2.0+ is required to protect against public gem pushes.'
   end
 
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
-  spec.bindir        = "exe"
+  spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
-  spec.require_paths = ["lib"]
+  spec.require_paths = ['lib']
 
-  spec.add_dependency 'conekta', "~> 0.5"
+  spec.add_dependency 'conekta', '~> 0.5'
   spec.add_dependency 'paypal-sdk-rest'
-  spec.add_development_dependency "bundler", "~> 1.10.a"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency 'bundler', '~> 1.10.a'
+  spec.add_development_dependency 'rake', '~> 10.0'
 end