Add resource framework: Base, CRUD mixins, and shared drafts/attachments/payments concerns

lib/fiken/resources/concerns/drafts.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Fiken
+  module Resources
+    module Concerns
+      # /<parent>/drafts — the draft lifecycle shared by invoices, credit notes,
+      # offers, order confirmations, sales and purchases.
+      class Drafts < Resource::Base
+        include Resource::Listable
+        include Resource::Findable
+        include Resource::Creatable
+        include Resource::Updatable # drafts update via PUT
+        include Resource::Deletable
+
+        def initialize(client, company_slug, parent_path, create_action)
+          super(client, company_slug)
+          @parent_path = parent_path
+          @create_action = create_action
+        end
+
+        def base_path
+          "#{@parent_path}/drafts"
+        end
+
+        def attachments(draft_id)
+          Attachments.new(client, company_slug, "#{base_path}/#{draft_id}")
+        end
+
+        # Finalize a draft into its document (e.g. createInvoice, createSale).
+        def create_document(draft_id, attributes = nil)
+          post_create("#{base_path}/#{draft_id}/#{@create_action}", attributes)
+        end
+      end
+    end
+  end
+end