Add Push notifications backend support

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

lib/graphql/resolvers/push_subscription.ex

@@ -0,0 +1,49 @@
+defmodule Mobilizon.GraphQL.Resolvers.PushSubscription do
+  @moduledoc """
+  Handles the push subscriptions-related GraphQL calls.
+  """
+
+  alias Mobilizon.Users
+  alias Mobilizon.Storage.Page
+  alias Mobilizon.Users.{PushSubscription, User}
+
+  @doc """
+  List all of an user's registered push subscriptions
+  """
+  def list_user_push_subscriptions(_parent, %{page: page, limit: limit}, %{
+        context: %{current_user: %User{id: user_id}}
+      }) do
+    %Page{} = page = Users.list_user_push_subscriptions(user_id, page, limit)
+    {:ok, page}
+  end
+
+  def list_user_push_subscriptions(_parent, _args, _resolution), do: {:error, :unauthenticated}
+
+  @doc """
+  Register a push subscription
+  """
+  def register_push_subscription(_parent, args, %{
+        context: %{current_user: %User{id: user_id}}
+      }) do
+    Users.create_push_subscription(Map.put(args, :user_id, user_id))
+  end
+
+  @spec unregister_push_subscription(map(), map(), map()) ::
+          {:ok, PushSubscription.t()} | {:error, :unauthorized} | {:error, :not_found}
+  def unregister_push_subscription(_parent, %{id: push_subscription_id}, %{
+        context: %{current_user: %User{id: user_id}}
+      }) do
+    with %PushSubscription{user: %User{id: push_subscription_user_id}} = push_subscription <-
+           Users.get_push_subscription(push_subscription_id),
+         {:user_owns_push_subscription, true} <-
+           {:user_owns_push_subscription, push_subscription_user_id == user_id} do
+      Users.delete_push_subscription(push_subscription)
+    else
+      {:user_owns_push_subscription, false} ->
+        {:error, :unauthorized}
+
+      nil ->
+        {:error, :not_found}
+    end
+  end
+end

lib/graphql/schema/users/push_subscription.ex

@@ -0,0 +1,34 @@
+defmodule Mobilizon.GraphQL.Schema.Users.PushSubscription do
+  @moduledoc """
+  Schema representation for PushSubscription
+  """
+  use Absinthe.Schema.Notation
+  alias Mobilizon.GraphQL.Resolvers.PushSubscription
+
+  @desc """
+  An object representing the keys for a push subscription
+  """
+  input_object :push_subscription_keys do
+    field(:p256dh, non_null(:string))
+    field(:auth, non_null(:string))
+  end
+
+  object :push_queries do
+    field :list_push_subscriptions, :paginated_push_subscription_list do
+      resolve(&PushSubscription.list_user_push_subscriptions/3)
+    end
+  end
+
+  object :push_mutations do
+    field :register_push_mutation, :string do
+      arg(:endpoint, non_null(:string))
+      arg(:keys, non_null(:push_subscription_keys))
+      resolve(&PushSubscription.register_push_subscription/3)
+    end
+
+    field :unregister_push_mutation, :string do
+      arg(:id, non_null(:id))
+      resolve(&PushSubscription.unregister_push_subscription/3)
+    end
+  end
+end