[WIP] Add base command object

app/controllers/v1/articles_controller.rb

@@ -2,12 +2,36 @@ module V1
   class ArticlesController < ApplicationController
     decorates_assigned :articles
 
+    before_action :fake_user
+
     def index
       authorize Article
+
+      @presenter = Articles::Index.call(user: current_user, **id_params)
+    end
+
+    def create
+      authorize Article
+
+      @form = Articles::Create.call(article_params)
+
+      return head :unprocessable_entity unless @form.success?
+
+      render 'articles/show'
+    end
+
+    private
+
+    def fake_user
+      @current_user = 'kek'
+    end
+
+    def article_params
+      params.require(:article).permit(:title, :body)
+    end
 
-      @articles = Article
-        .page(params[:page])
-        .per(params[:per_page])
+    def id_params
+      params.permit(:left_id, :right_id).deep_symbolize_keys
     end
   end
 end

app/facades/articles/index_facade.rb

@@ -0,0 +1,33 @@
+module Articles
+  class IndexFacade
+    attr_reader :user
+
+    def initialize(user:, **params)
+      @user     = user
+      @left_id  = params[:left_id]
+      @right_id = params[:right_id]
+      @page     = params[:page]
+      @per_page = params[:per_page]
+    end
+
+    def articles
+      @articles ||= FindAndOrder
+        .call(ids
+        .result
+        .page(page)
+        .per(per_page)
+        .load
+    end
+
+    private
+
+    attr_reader :left_id, :right_id, :page, :per_page
+
+    def ids
+      {
+        left_id: left_id,
+        right_id: right_id
+      }
+    end
+  end
+end

app/forms/articles/create.rb

@@ -0,0 +1,15 @@
+module Articles
+  class Create < Commando::Base
+    def initialize(**params)
+      @params = params
+    end
+
+    def call
+      Article.create(params)
+    end
+
+    private
+
+    attr_reader :params
+  end
+end

app/models/article.rb

@@ -1,2 +1,21 @@
 class Article < ApplicationRecord
+  # TODO: Replace with Form Object
+  MIN_BODY      = 10
+  MAX_BODY      = 200
+  MIN_TITLE     = 3
+  MAX_TITLE     = 100
+  INVALID_REGEX = /.?kek.?/
+
+  validates :title, length: { in: MIN_TITLE..MAX_TITLE }
+  validates :body,  length: { in: MIN_BODY..MAX_BODY }
+
+  validate :check_body!
+
+  private
+
+  def check_body!
+    return unless body.to_s.match?(INVALID_REGEX)
+
+    errors.add(:body, 'Invalid body')
+  end
 end

app/operations/articles/index.rb

@@ -0,0 +1,49 @@
+module Articles
+  class Index < Commando::Base
+    DEFAULT_LEFT_ID  = 0
+    DEFAULT_RIGHT_ID = 0
+    DEFAULT_PAGE     = 1
+    DEFAULT_PER_PAGE = 25
+
+    run_before :delay_task
+    run_after  :send_email, :add_errors
+
+    def initialize(user:, **params)
+      @user     = user
+      @left_id  = params.fetch(:left_id,  DEFAULT_LEFT_ID)
+      @right_id = params.fetch(:right_id, DEFAULT_RIGHT_ID)
+      @page     = params.fetch(:page,     DEFAULT_PAGE)
+      @per_page = params.fetch(:per_page, DEFAULT_PER_PAGE)
+    end
+
+    private
+
+    attr_reader :user, :left_id, :right_id, :page, :per_page
+
+    def call
+      Article.new(body: 'kekekekekek').tap(&:save)
+    end
+
+    def delay_task
+      puts '========= Task has been queued! =========='
+    end
+
+    def send_email
+      puts '========= Email has been sent! =========='
+    end
+
+    def add_errors
+      errors << { lel: 'Ey dyadya stope!', base: 'Oce ti dyadya daesh!' }
+    end
+
+    def facade
+      @facade ||= ::Articles::IndexFacade.new(
+        user:     user,
+        left_id:  left_id,
+        right_id: right_id,
+        page:     page,
+        per_page: per_page
+      )
+    end
+  end
+end

app/queries/application_query.rb

@@ -0,0 +1,19 @@
+class ApplicationQuery < Commando::Base
+  delegate :resource_class, :resource_name, to: :class
+
+  def self.resource_name
+    parent_name.singularize
+  end
+
+  def self.resource_class
+    resource_name.constantize
+  rescue NameError
+    raise "Scope model haven't been defined"
+  end
+
+  def scope
+    @result ||= resource_class.all
+  end
+
+  alias_method :result, :scope
+end

app/queries/articles/find.rb

@@ -0,0 +1,16 @@
+module Articles
+  class Find < ApplicationQuery
+    def initialize(left_id:, right_id:)
+      @left_id  = left_id
+      @right_id = right_id
+    end
+
+    def call
+      scope.where('id >= ? AND id <= ?', left_id, right_id)
+    end
+
+    private
+
+    attr_reader :left_id, :right_id
+  end
+end

app/queries/articles/find_and_order.rb

@@ -0,0 +1,20 @@
+module Articles
+  class FindAndOrder < ApplicationQuery
+    def initialize(left_id:, right_id:)
+      @left_id  = left_id
+      @right_id = right_id
+    end
+
+    def call
+      ReverseOrder.call(scope: found_entries)
+    end
+
+    def found_entries
+      Find.call(left_id: left_id, right_id: right_id)
+    end
+
+    private
+
+    attr_reader :left_id, :right_id
+  end
+end

app/queries/articles/reverse_order.rb

@@ -0,0 +1,11 @@
+module Articles
+  class ReverseOrder < ApplicationQuery
+    def initialize(**params)
+      @scope = params.fetch(:scope, scope)
+    end
+
+    def call
+      scope.order(id: :desc)
+    end
+  end
+end

app/views/v1/articles/index.json.jbuilder

@@ -0,0 +1,5 @@
+json.articles do
+  json.array! @presenter.articles, partial: 'articles/article', as: :article
+end
+
+json.user @presenter.user

app/views/v1/articles/show.json.jbuilder

@@ -0,0 +1 @@
+json.partial! 'articles/article', article: @form.result

config/application.rb

@@ -15,7 +15,15 @@
 
 module RailsApiSkeleton
   class Application < Rails::Application
+    ADDITIONAL_ABSTRACTION_LAYERS = %w[operations].freeze
+    LIB_PATH                      = Rails.root.join('lib').freeze
+
     config.load_defaults 5.1
     config.api_only = true
+
+    config.autoload_paths += [
+      *ADDITIONAL_ABSTRACTION_LAYERS,
+      LIB_PATH
+    ]
   end
 end

config/locales/en.yml

@@ -1,2 +1,8 @@
 en:
   hello: "Hello world"
+
+  errors:
+    commands:
+      articles:
+        index:
+          lel: ''

config/routes/v1/articles.rb

@@ -2,7 +2,7 @@ module Routes
   module V1
     module Articles
       def call
-        resources :articles, only: %i[index]
+        resources :articles, only: %i[index create]
       end
     end
   end

lib/commando/base.rb

@@ -0,0 +1,24 @@
+module Commando
+  class Base
+    extend Hooks
+    extend Callable
+
+    include Status
+    include Errorable
+    include Trace
+
+    attr_reader :result
+
+    def call
+      raise NotImplementedError, Constants::NOT_IMPLEMENTED_MESSAGE
+    end
+
+    private
+
+    def called!
+      super
+
+      build_errors
+    end
+  end
+end

lib/commando/callable.rb

@@ -0,0 +1,22 @@
+module Commando
+  module Callable
+    def call(*args)
+      instance(*args).tap do |object|
+        object.instance_variable_set(:@result, object.call)
+        object.send(:called!)
+
+        return yield(*block_args(object)) if block_given?
+      end
+    end
+
+    private
+
+    def instance(*args)
+      new(*args)
+    end
+
+    def block_args(object)
+      Constants::BLOCK_ARGS.map { |method_name| object.send(method_name) }
+    end
+  end
+end

lib/commando/constants.rb

@@ -0,0 +1,8 @@
+module Commando
+  module Constants
+    BLOCK_ARGS                = %i[result success? errors].freeze
+    TRACEABLE_ATTRIBUTES      = %i[success? called? errors].freeze
+    NOT_IMPLEMENTED_MESSAGE   = '`#call` method has to be implemented'.freeze
+    DEFAULT_ERROR_FORMAT_PATH = 'errors.commands.format'.freeze
+  end
+end

lib/commando/error/collection.rb

@@ -0,0 +1,29 @@
+module Commando
+  module Error
+    class Collection < Hash
+      include Error::I18n
+
+      attr_reader :base
+
+      def initialize(base:)
+        @base = base
+      end
+
+      def add(key, value, **_opts)
+        self[key] = fetch(key, []).push(value).uniq
+      end
+
+      def merge(errors_hash)
+        errors_hash.each do |key, values|
+          Array(values).each { |value| add(key, value) }
+        end
+      end
+
+      def each
+        each_key { |field| self[field].each { |message| yield(field, message) } }
+      end
+
+      alias_method :<<, :merge
+    end
+  end
+end

lib/commando/error/i18n.rb

@@ -0,0 +1,31 @@
+module Commando
+  module Error
+    module I18n
+      def full_messages
+        map { |attribute, message| full_message(attribute, message) }
+      end
+
+      def full_message(attribute, message)
+        return message if attribute == :base
+
+        i18n_decorator(attribute, message).full_message
+      end
+
+      def full_messages_for(attribute)
+        fetch(attribute, []).map { |message| full_message(attribute, message) }
+      end
+
+      private
+
+      delegate :i18n_path, to: :base
+
+      def i18n_decorator(attribute, message)
+        I18nDecorator.new(
+          attribute: attribute,
+          message:   message,
+          i18n_path: i18n_path
+        )
+      end
+    end
+  end
+end