feat: add groups administration #372

lib/membership/membership.ex

@@ -244,4 +244,48 @@ defmodule Mv.Membership do
     |> Ash.Changeset.for_update(:update_single_member_field_visibility, %{})
     |> Ash.update(domain: __MODULE__)
   end
+
+  @doc """
+  Gets a group by its slug.
+
+  Uses `Ash.Query.filter` to efficiently find a group by its slug.
+  The unique index on `slug` ensures efficient lookup performance.
+  The slug lookup is case-sensitive (exact match required).
+
+  ## Parameters
+
+    - `slug` - The slug to search for (case-sensitive)
+    - `opts` - Options including `:actor` for authorization
+
+  ## Returns
+
+    - `{:ok, group}` - Found group (with members and member_count loaded)
+    - `{:ok, nil}` - Group not found
+    - `{:error, error}` - Error reading group
+
+  ## Examples
+
+      iex> {:ok, group} = Mv.Membership.get_group_by_slug("board-members", actor: actor)
+      iex> group.name
+      "Board Members"
+
+      iex> {:ok, nil} = Mv.Membership.get_group_by_slug("non-existent", actor: actor)
+      {:ok, nil}
+
+  """
+  def get_group_by_slug(slug, opts \\ []) do
+    actor = Keyword.get(opts, :actor)
+    load_opts = Keyword.get(opts, :load, [:members, :member_count])
+
+    require Ash.Query
+
+    query =
+      Mv.Membership.Group
+      |> Ash.Query.filter(slug == ^slug)
+      |> Ash.Query.load(load_opts)
+
+    opts_with_actor = if actor, do: [actor: actor], else: []
+
+    Ash.read_one(query, opts_with_actor)
+  end
 end