Add DFC Provider engine

Gemfile

@@ -11,6 +11,7 @@ gem 'rails_safe_tasks', '~> 1.0'
 gem "activerecord-import"
 
 gem "catalog", path: "./engines/catalog"
+gem 'dfc_provider', path: './engines/dfc_provider'
 gem "order_management", path: "./engines/order_management"
 gem 'web', path: './engines/web'
 

Gemfile.lock

@@ -56,6 +56,11 @@ GIT
       rails-i18n
       spree_core (>= 1.1)
 
+PATH
+  remote: engines/dfc_provider
+  specs:
+    dfc_provider (0.0.1)
+
 PATH
   remote: engines/catalog
   specs:
@@ -710,6 +715,7 @@ DEPENDENCIES
   delayed_job_web
   devise (~> 2.2.5)
   devise-encryptable (= 0.2.0)
+  dfc_provider!
   diffy
   eventmachine (>= 1.2.3)
   factory_bot_rails

config/routes.rb

@@ -91,4 +91,5 @@ Openfoodnetwork::Application.routes.draw do
 
   # Mount Spree's routes
   mount Spree::Core::Engine, :at => '/'
+  mount DfcProvider::Engine, at: '/'
 end

engines/dfc_provider/app/controllers/api/dfc_provider/products_controller.rb

@@ -0,0 +1,26 @@
+module Api::DfcProvider
+  class ProductsController < ActionController::Base
+    before_filter :set_enterprise
+
+    def index
+      products = @enterprise.inventory_variants
+                            .includes(:product, :inventory_items)
+
+      products_json = DfcProvider::ProductSerializer
+                      .new(@enterprise, products, base_url)
+                      .serialized_json
+
+      render json: products_json
+    end
+
+    private
+
+    def set_enterprise
+      @enterprise = ::Enterprise.find(params[:enterprise_id])
+    end
+
+    def base_url
+      "#{root_url}api/dfc_provider"
+    end
+  end
+end

engines/dfc_provider/app/serializers/dfc_provider/product_serializer.rb

@@ -0,0 +1,28 @@
+module DfcProvider
+  class ProductSerializer
+    def initialize(enterprise, products, base_url)
+      @enterprise = enterprise
+      @products = products
+      @base_url = base_url
+    end
+
+    def serialized_json
+      {
+        "@context" =>
+          {
+            "DFC" => "http://datafoodconsortium.org/ontologies/DFC_FullModel.owl#",
+            "@base" => @base_url
+          },
+         "@id" => "/enterprises/#{@enterprise.id}/products",
+         "DFC:supplies" => @products.map do |variant|
+            {
+              "DFC:description" => variant.name,
+              "DFC:quantity" => variant.total_on_hand,
+              "@id" => variant.id,
+              "DFC:hasUnit" => {"@id" => "/unit/#{variant.unit_description.presence || 'piece' }"}
+            }
+          end
+        }.to_json
+    end
+  end
+end

engines/dfc_provider/config/routes.rb

@@ -0,0 +1,9 @@
+DfcProvider::Engine.routes.draw do
+  namespace :api do
+    namespace :dfc_provider do
+      resources :enterprises, only: :none do
+        resources :products, only: %i[index]
+      end
+    end
+  end
+end

engines/dfc_provider/dfc_provider.gemspec

@@ -0,0 +1,16 @@
+$:.push File.expand_path("../lib", __FILE__)
+
+# Maintain your gem's version:
+require "dfc_provider/version"
+
+# Describe your gem and declare its dependencies:
+Gem::Specification.new do |s|
+  s.name        = 'dfc_provider'
+  s.version     = DfcProvider::VERSION
+  s.authors     = ['Admin OFF']
+  s.email       = ['admin@openfoodfrance.org']
+  s.summary     = 'Provdes an API stack implementing DFC semantic specifications'
+
+  s.files = Dir["{app,config,db,lib}/**/*"] + ['MIT-LICENSE', 'Rakefile', 'README.rdoc']
+  s.test_files = Dir['test/**/*']
+end

engines/dfc_provider/lib/dfc_provider.rb

@@ -0,0 +1,4 @@
+require "dfc_provider/engine"
+
+module DfcProvider
+end

engines/dfc_provider/lib/dfc_provider/engine.rb

@@ -0,0 +1,5 @@
+module DfcProvider
+  class Engine < ::Rails::Engine
+    isolate_namespace DfcProvider
+  end
+end

engines/dfc_provider/lib/dfc_provider/version.rb

@@ -0,0 +1,3 @@
+module DfcProvider
+  VERSION = "0.0.1"
+end