Introduce group posts

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/metadata/utils.ex

@@ -3,10 +3,34 @@ defmodule Mobilizon.Service.Metadata.Utils do
   Tools to convert tags to string.
   """
 
+  alias Mobilizon.Service.Formatter.HTML, as: HTMLFormatter
   alias Phoenix.HTML
+  import Mobilizon.Web.Gettext
 
+  @slice_limit 200
+
+  @spec stringify_tags(Enum.t()) :: String.t()
   def stringify_tags(tags), do: Enum.reduce(tags, "", &stringify_tag/2)
 
   defp stringify_tag(tag, acc) when is_tuple(tag), do: acc <> HTML.safe_to_string(tag)
   defp stringify_tag(tag, acc) when is_binary(tag), do: acc <> tag
+
+  @spec strip_tags(String.t()) :: String.t()
+  def strip_tags(text), do: HTMLFormatter.strip_tags(text)
+
+  @spec process_description(String.t(), String.t(), integer()) :: String.t()
+  def process_description(description, locale \\ "en", limit \\ @slice_limit)
+  def process_description(nil, locale, limit), do: process_description("", locale, limit)
+
+  def process_description("", locale, _limit) do
+    Gettext.put_locale(locale)
+    gettext("The event organizer didn't add any description.")
+  end
+
+  def process_description(description, _locale, limit) do
+    description
+    |> HTMLFormatter.strip_tags()
+    |> String.slice(0..limit)
+    |> (&"#{&1}…").()
+  end
 end