diff.patch

diff --git lib/hive/acquisitions/document_template.ex lib/hive/acquisitions/document_template.ex
index 411b0d8a..2ce227ee 100644
--- lib/hive/acquisitions/document_template.ex
+++ lib/hive/acquisitions/document_template.ex
@@ -21,7 +21,21 @@ defmodule Hive.Acquisitions.DocumentTemplate do
 
     has_many(
       :processes_templates,
-      through: [:processes_templates_documents_templates, :process_template]
+      through: [:processes_templates_documents_templates, :process_template],
+      where: [archived_at: nil]
+    )
+
+    has_many(
+      :processes_templates_latest_versions,
+      through: [:processes_templates_documents_templates, :process_template, :last_version]
+    )
+
+    # é o mesmo id da primeira versão criada
+    field(:template_id, Ecto.UUID)
+
+    has_one(:last_version, __MODULE__,
+      foreign_key: :id,
+      references: :template_id
     )
 
     # FIXME: @deprecated fields
diff --git lib/hive/acquisitions/process_template.ex lib/hive/acquisitions/process_template.ex
index 5bd6c0ce..2f70d390 100644
--- lib/hive/acquisitions/process_template.ex
+++ lib/hive/acquisitions/process_template.ex
@@ -35,14 +35,46 @@ defmodule Hive.Acquisitions.ProcessTemplate do
     has_many(:companies, through: [:companies_groups, :company])
     has_many(:processes_templates_documents_templates, ProcessTemplateDocumentTemplate)
 
+    # é o mesmo id da primeira versão criada
+    field(:template_id, :binary_id)
+
+    has_one(:last_version, __MODULE__,
+      foreign_key: :id,
+      references: :template_id
+    )
+
     has_many(
       :documents_templates,
       through: [:processes_templates_documents_templates, :document_template]
     )
 
+    has_many(
+      :documents_templates_latest_versions,
+      through: [:processes_templates_documents_templates, :document_template, :last_version]
+    )
+
+    # to support order_by, need the fork: https://github.com/elixir-ecto/ecto/pull/2859
+    # has_many(:processes_templates_documents_templates, ProcessTemplateDocumentTemplate,
+    #   order_by: [asc: :order]
+    # )
+
     timestamps()
   end
 
+  @doc """
+  """
+  def preload_last_documents_templates(query) do
+    query |> Repo.preload(documents_templates: preload_last_documents_templates_query())
+  end
+
+  def preload_last_documents_templates_query do
+    from(
+      dt in DocumentTemplate,
+      distinct: dt.template_id,
+      order_by: [desc: dt.created_at]
+    )
+  end
+
   @doc """
   Builds a changeset based on the `struct` and `params`.
   """
diff --git lib/hive/acquisitions/process_template_document_template.ex lib/hive/acquisitions/process_template_document_template.ex
index bc4af256..da538b7e 100644
--- lib/hive/acquisitions/process_template_document_template.ex
+++ lib/hive/acquisitions/process_template_document_template.ex
@@ -6,8 +6,8 @@ defmodule Hive.Acquisitions.ProcessTemplateDocumentTemplate do
   schema "processes_templates_documents_templates" do
     field(:order, :integer)
 
-    belongs_to(:document_template, DocumentTemplate, foreign_key: :document_template_id)
-    belongs_to(:process_template, ProcessTemplate, foreign_key: :process_template_id)
+    belongs_to(:document_template, DocumentTemplate)
+    belongs_to(:process_template, ProcessTemplate)
 
     timestamps()
   end