From d0b45de175eccf7a5a39296e681df6f5381de635 Mon Sep 17 00:00:00 2001
From: Thomas Citharel <tcit@tcit.fr>
Date: Mon, 25 Oct 2021 13:18:46 +0200
Subject: [PATCH] Expose person follows

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
---
 lib/graphql/resolvers/person.ex     | 47 +++++++++++++++++++++++++++--
 lib/graphql/schema/actors/person.ex | 15 +++++++++
 lib/mobilizon/actors/actors.ex      |  8 +++++
 3 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/lib/graphql/resolvers/person.ex b/lib/graphql/resolvers/person.ex
index 709927d40..1076d72b4 100644
--- a/lib/graphql/resolvers/person.ex
+++ b/lib/graphql/resolvers/person.ex
@@ -6,7 +6,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   import Mobilizon.Users.Guards
 
   alias Mobilizon.{Actors, Events, Users}
-  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Actors.{Actor, Follower, Member}
   alias Mobilizon.Events.Participant
   alias Mobilizon.Storage.{Page, Repo}
   alias Mobilizon.Users.User
@@ -355,7 +355,7 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
   end
 
   @doc """
-  Returns the list of events this person is going to
+  Returns this person's group memberships
   """
   @spec person_memberships(Actor.t(), map(), map()) :: {:ok, Page.t()} | {:error, String.t()}
   def person_memberships(%Actor{id: actor_id} = person, %{group: group}, %{
@@ -398,6 +398,49 @@ defmodule Mobilizon.GraphQL.Resolvers.Person do
     end
   end
 
+  @doc """
+  Returns this person's group follows
+  """
+  @spec person_follows(Actor.t(), map(), map()) :: {:ok, Page.t()} | {:error, String.t()}
+  def person_follows(%Actor{id: actor_id} = person, %{group: group}, %{
+        context: %{current_user: %User{} = user}
+      }) do
+    if user_can_access_person_details?(person, user) do
+      with {:group, %Actor{} = group} <- {:group, Actors.get_actor_by_name(group, :Group)},
+           %Follower{} = follow <-
+             Actors.get_follower_by_followed_and_following(group, person) do
+        {:ok,
+         %Page{
+           total: 1,
+           elements: [follow]
+         }}
+      else
+        nil ->
+          {:ok, %Page{total: 0, elements: []}}
+
+        {:group, nil} ->
+          {:error, :group_not_found}
+      end
+    else
+      {:error, dgettext("errors", "Profile is not owned by authenticated user")}
+    end
+  end
+
+  def person_follows(
+        %Actor{} = person,
+        %{page: page, limit: limit},
+        %{
+          context: %{current_user: %User{} = user}
+        }
+      ) do
+    if user_can_access_person_details?(person, user) do
+      follows = Actors.list_paginated_follows_for_actor(person, page, limit)
+      {:ok, follows}
+    else
+      {:error, dgettext("errors", "Profile is not owned by authenticated user")}
+    end
+  end
+
   @spec user_for_person(Actor.t(), map(), Absinthe.Resolution.t()) ::
           {:ok, User.t() | nil} | {:error, String.t() | nil}
   def user_for_person(%Actor{type: :Person, user_id: user_id}, _args, %{
diff --git a/lib/graphql/schema/actors/person.ex b/lib/graphql/schema/actors/person.ex
index 42743316f..65fd6c54a 100644
--- a/lib/graphql/schema/actors/person.ex
+++ b/lib/graphql/schema/actors/person.ex
@@ -102,6 +102,21 @@ defmodule Mobilizon.GraphQL.Schema.Actors.PersonType do
       arg(:limit, :integer, default_value: 10, description: "The limit of memberships per page")
       resolve(&Person.person_memberships/3)
     end
+
+    @desc "The list of groups this person follows"
+    field(:follows, :paginated_follower_list,
+      description: "The list of groups this person follows"
+    ) do
+      arg(:group, :string, description: "Filter by group federated username")
+
+      arg(:page, :integer,
+        default_value: 1,
+        description: "The page in the follows list"
+      )
+
+      arg(:limit, :integer, default_value: 10, description: "The limit of follows per page")
+      resolve(&Person.person_follows/3)
+    end
   end
 
   @desc """
diff --git a/lib/mobilizon/actors/actors.ex b/lib/mobilizon/actors/actors.ex
index 68fe1fdcb..da6b0e848 100644
--- a/lib/mobilizon/actors/actors.ex
+++ b/lib/mobilizon/actors/actors.ex
@@ -1030,6 +1030,14 @@ defmodule Mobilizon.Actors do
     |> Repo.delete()
   end
 
+  @spec list_paginated_follows_for_actor(Actor.t(), integer | nil, integer | nil) ::
+          Page.t(Follower.t())
+  def list_paginated_follows_for_actor(%Actor{id: actor_id}, page \\ nil, limit \\ nil) do
+    actor_id
+    |> followings_for_actor_query
+    |> Page.build_page(page, limit)
+  end
+
   @doc """
   Returns the list of external followers for an actor.
   """