# == Schema Information
#
# Table name: products
#
#  id         :integer          not null, primary key
#  name       :string
#  price      :decimal(12, 2)
#  created_at :datetime         not null
#  updated_at :datetime         not null
#

class Product < ApplicationRecord
    has_many :categories

    after_create :save_categories

    #attr_reader :categories

    validates :name, presence: true
    validates :price, presence: true

  #Custom setter
    def categories=(value)
        @categories = value
    end

    private

    def save_categories
    @categories.each do |category_id|
            HasCategory.create(category_id: category_id, product_id: self.id) #self es una instancia de product
        end
    end

end

# == Schema Information
#
# Table name: has_categories
#
#  id          :integer          not null, primary key
#  product_id  :integer
#  category_id :integer
#  created_at  :datetime         not null
#  updated_at  :datetime         not null
#

class HasCategory < ApplicationRecord
  belongs_to :product
  belongs_to :category
end

# == Schema Information
#
# Table name: categories
#
#  id         :integer          not null, primary key
#  name       :string
#  created_at :datetime         not null
#  updated_at :datetime         not null
#

class Category < ApplicationRecord
    validates :name, presence: true
    has_many :products
end

<div class="container">
  <div class="row">
    <div class="col-sm-4 col-sm-offset-4">
      <h1><%= form_title %></h1>

      <% if @product.errors.any? %>
        <div class="alert alert-danger">
          <ul>
          <% @product.errors.full_messages.each do |msg| %>
           <li><%= msg %></li>
          <% end %>
          </ul>
        </div>
      <% end %>

      <%= form_for @product do |f| %>
        <div class="form-group">
          <%= f.text_field :name, class: "form-control input-lg", placeholder: "Nombre del producto"%>
        </div>
        <div class="form-group">
              <%= f.number_field :price, class: "form-control input-lg", placeholder: "Precio del producto" %>
        </div>
        <div class="field">
          <% if !@categories.nil? %>
            <% @categories.each do |category| %>
               <div class="field">
                 <%= check_box_tag "categories[]", category.id %> <%= category.name %>
               </div>
            <% end %>
          <% end %>
         </div>
        <div>
          <%= f.submit form_title, class: "btn btn-primary btn-lg btn-block" %>
        </div>
      <% end %>
    </div>
  </div>
</div>