RoR - check presence in has_many polimorphic reference in the view

I am making an app with User, Submissions and Comments. I need both the submissions and comments to have a Like button, so after some researching I finally created a Like model, using the reference to user and a polimorphic reference to Submission and Comment. As I am new in RoR, I share the code I have so you can correct me if there is something wrong:

guser.rb:

class Guser < ActiveRecord::Base
  has_many :likes, dependent: :destroy
end

like.rb:

class Like < ActiveRecord::Base
  belongs_to :guser
  belongs_to :likeable, polymorphic: true
end

submission.rb:

class Submission < ActiveRecord::Base
  belongs_to :guser
  has_many :comments
  ... 
  has_many :likes, as: :likeable
  has_many :likers, through: :likes, source: :user
end

comment.rb:

class Comment < ActiveRecord::Base
  ...  
  has_many :likes, as: :likeable
  has_many :likers, through: :likes, source: :user
end

migration create_likes:

class CreateLikes < ActiveRecord::Migration
  def change
    create_table :likes do |t|
      t.integer :likeable_id
      t.string  :likeable_type
      t.references :guser, index: true, foreign_key: true
      t.timestamps null: false
    end
  end
end

Now my question is: I need to only show the like button if the submission/comment has not been already liked by the user. So now I need to do something like this:

<%if current_guser and not current_guser.likes.map(&:submission_id).include? submission.id %>
      <%= link_to(image_tag("http://ift.tt/1SB1yKg", :width => 8, :height => 8), { :controller => "likes", :submission_id => submission.id,:action => "create"}, method: :post) %>

But now I need to check if the likeable_type is submission and the likeable_id matches with the submission id. And, in the comments view I must do the same but with the comments. How can I do this check? Is there any includes function for a map with more than one attribute?

Thank you!