Refactor adding tags to an event

Also refactor extracting tags from content, now uses Pleroma's Formatter

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

lib/mobilizon/events/event.ex

@@ -86,7 +86,6 @@ defmodule Mobilizon.Events.Event do
       :uuid,
       :picture_id
     ])
-    |> cast_assoc(:tags)
     |> cast_assoc(:physical_address)
     |> validate_required([
       :title,

lib/mobilizon/events/events.ex

@@ -367,7 +367,7 @@ defmodule Mobilizon.Events do
 
   """
   def create_event(attrs \\ %{}) do
-    with {:ok, %Event{} = event} <- %Event{} |> Event.changeset(attrs) |> Repo.insert(),
+    with %Event{} = event <- do_create_event(attrs),
          {:ok, %Participant{} = _participant} <-
            %Participant{}
            |> Participant.changeset(%{
@@ -376,7 +376,24 @@ defmodule Mobilizon.Events do
              event_id: event.id
            })
            |> Repo.insert() do
-      {:ok, Repo.preload(event, [:organizer_actor])}
+      {:ok, event}
+    end
+  end
+
+  defp do_create_event(attrs) do
+    with {:ok, %Event{} = event} <- %Event{} |> Event.changeset(attrs) |> Repo.insert(),
+         %Event{} = event <- event |> Repo.preload([:tags, :organizer_actor]),
+         {:has_tags, true, _} <- {:has_tags, Map.has_key?(attrs, "tags"), event} do
+      event
+      |> Ecto.Changeset.change()
+      |> Ecto.Changeset.put_assoc(:tags, attrs["tags"])
+      |> Repo.update()
+    else
+      {:has_tags, false, event} ->
+        event
+
+      error ->
+        error
     end
   end
 
@@ -491,6 +508,22 @@ defmodule Mobilizon.Events do
   """
   def get_tag!(id), do: Repo.get!(Tag, id)
 
+  def get_tag(id), do: Repo.get(Tag, id)
+
+  @doc """
+  Get an existing tag or create one
+  """
+  @spec get_or_create_tag(String.t()) :: {:ok, Tag.t()} | {:error, any()}
+  def get_or_create_tag(title) do
+    case Repo.get_by(Tag, title: title) do
+      %Tag{} = tag ->
+        {:ok, tag}
+
+      nil ->
+        create_tag(%{"title" => title})
+    end
+  end
+
   @doc """
   Creates a tag.