#350 REST API Versioning

rails g migration change_products_released_on
rake db:migrate
cp -R app/controllers/api/v1 app/controllers/api/v2
curl -H 'Accept: application/vnd.example.v1' http://localhost:3000/api/products

require 'api_constraints'

Store::Application.routes.draw do
  namespace :api, defaults: {format: 'json'} do
    scope module: :v1, constraints: ApiConstraints.new(version: 1) do
      resources :products
    end
    scope module: :v2, constraints: ApiConstraints.new(version: 2, default: true) do
      resources :products
    end
  end
  
  resources :products
  root to: 'products#index'
end

class ApiConstraints
  def initialize(options)
    @version = options[:version]
    @default = options[:default]
  end

  def matches?(req)
    @default || req.headers['Accept'].include?("application/vnd.example.v#{@version}")
  end
end

module Api
  module V1
    class ProductsController < ApplicationController
      class Product < ::Product
        # Note: this does not take into consideration the create/update actions for changing released_on
        def as_json(options = {})
          super.merge(released_on: released_at.to_date)
        end
      end
      
      respond_to :json

      def index
        respond_with Product.all
      end

      def show
        respond_with Product.find(params[:id])
      end

      def create
        respond_with Product.create(params[:product])
      end

      def update
        respond_with Product.update(params[:id], params[:product])
      end

      def destroy
        respond_with Product.destroy(params[:id])
      end
    end
  end
end