Add :eph field to %TranslationUnit{} and remove :sibling_with

Using :eph from now on to store ephemeral data like :sibling_with. Additionally
added cleaning up :eph before saving to db. And renamed InternalTree.Basic
to InternalTree.RawInternalBasic to make clear that it contains function
for an intermediary tree structure.

lib/outlook/internal_tree/raw_internal_basic.ex

@@ -0,0 +1,74 @@
+defmodule Outlook.InternalTree.RawInternalBasic do
+ @moduledoc """
+ Function used for the raw_internal_tree which is a transitory state after importing
+ Html and before splitting textnodes into %TranslationUnit{}s.
+ """
+
+  alias Ecto.UUID
+  alias Outlook.InternalTree.InternalNode
+  alias Outlook.InternalTree.TranslationUnit
+  alias Outlook.InternalTree.Html
+
+  @splitmarker "@@translationunit@@"
+
+  def set_split_markers([ %InternalNode{type: :text} = textnode | rest ]) do
+    [ %InternalNode{textnode |
+        content: String.replace(textnode.content, ~r|([.?!]["'”]?\s*)|u, "\\1#{@splitmarker}")
+        } | set_split_markers(rest) ]
+  end
+
+  def set_split_markers([ %InternalNode{type: :element} = node | rest ]) do
+    [ %InternalNode{node | content: set_split_markers(node.content)}
+      | set_split_markers(rest) ]
+  end
+
+  def set_split_markers([ node | rest ]) do
+    [ node | set_split_markers(rest) ]
+  end
+
+  def set_split_markers([]), do: []
+
+  def partition_textnodes([ %InternalNode{type: :element} = node | rest ]) do
+    [ %InternalNode{node | content: case get_sibling_collocation(node.content) do
+        :block -> partition_textnodes(node.content)
+        :inline -> inline_to_translation_units(node.content)
+        _ -> [ node ]
+      end
+    } | partition_textnodes(rest) ]
+  end
+
+  def partition_textnodes([ node | rest ]) do
+    [ node | partition_textnodes(rest) ]
+  end
+
+  def partition_textnodes([]), do: []
+
+
+  defp inline_to_translation_units(contents) do
+    contents
+      # |> Html.strip_attributes  # to be implemented
+      |> Html.to_html()
+      |> String.split(@splitmarker, trim: true)
+      |> Enum.map(fn sentence ->
+        %TranslationUnit{
+          content: sentence,
+          status: :untranslated,
+          uuid: UUID.generate()
+        }
+        end
+      )
+  end
+
+  defp contains_elements?(content) do
+
+  end
+
+  @doc "Returns just either :block or :inline. Assumes that it doesn't contain both."
+  def get_sibling_collocation(content) do
+    content
+    |> Enum.map(fn node -> node.eph.sibling_with end)
+    |> Enum.uniq()
+    |> List.delete(:both)
+    |> List.first
+  end
+end