Implement search engine & service in backend

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

lib/service/search.ex

@@ -0,0 +1,59 @@
+defmodule Mobilizon.Service.Search do
+  @moduledoc """
+  Module to handle search service
+  """
+
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Storage.Repo
+  alias Ecto.Adapters.SQL
+
+  def insert_search_event(%Event{} = event) do
+    SQL.query(
+      Repo,
+      """
+        INSERT INTO event_search(id, title, document) VALUES ($1, $2, (
+          SELECT
+            setweight(to_tsvector(unaccent($2)), 'A') ||
+            setweight(to_tsvector(unaccent(coalesce($4, ' '))), 'B') ||
+            setweight(to_tsvector(unaccent($3)), 'C')
+          )
+        );
+      """,
+      [
+        event.id,
+        event.title,
+        HtmlSanitizeEx.strip_tags(event.description),
+        get_tags_string(event)
+      ]
+    )
+  end
+
+  def update_search_event(%Event{} = event) do
+    SQL.query(
+      Repo,
+      """
+        UPDATE event_search
+          SET document =
+            (SELECT
+              setweight(to_tsvector(unaccent($2)), 'A') ||
+              setweight(to_tsvector(unaccent(coalesce($4, ' '))), 'B') ||
+              setweight(to_tsvector(unaccent($3)), 'C')
+            ),
+          title = $2
+          WHERE id = $1;
+      """,
+      [
+        event.id,
+        event.title,
+        HtmlSanitizeEx.strip_tags(event.description),
+        get_tags_string(event)
+      ]
+    )
+  end
+
+  defp get_tags_string(%Event{tags: tags}) do
+    tags
+    |> Enum.map(& &1.title)
+    |> Enum.join(" ")
+  end
+end