/api/v1/accounts/familiar_followers

Signed-off-by: marcin mikołajczak <git@mkljczk.pl>

changelog.d/familiar-followers.add

@@ -0,0 +1 @@
+Implement `/api/v1/accounts/familiar_followers`

lib/pleroma/user.ex

@@ -1404,6 +1404,40 @@ def get_friends_ids(%User{} = user, page \\ nil) do
     |> Repo.all()
   end
 
+  @spec get_familiar_followers_query(User.t(), User.t(), pos_integer() | nil) :: Ecto.Query.t()
+  def get_familiar_followers_query(%User{} = user, %User{} = current_user, nil) do
+    friends =
+      get_friends_query(current_user)
+      |> where([u], not u.hide_follows)
+      |> select([u], u.id)
+
+    User.Query.build(%{is_active: true})
+    |> where([u], u.id not in ^[user.id, current_user.id])
+    |> join(:inner, [u], r in FollowingRelationship,
+      as: :followers_relationships,
+      on: r.following_id == ^user.id and r.follower_id == u.id
+    )
+    |> where([followers_relationships: r], r.state == ^:follow_accept)
+    |> where([followers_relationships: r], r.follower_id in subquery(friends))
+  end
+
+  def get_familiar_followers_query(%User{} = user, %User{} = current_user, page) do
+    user
+    |> get_familiar_followers_query(current_user, nil)
+    |> User.Query.paginate(page, 20)
+  end
+
+  @spec get_familiar_followers_query(User.t(), User.t()) :: Ecto.Query.t()
+  def get_familiar_followers_query(%User{} = user, %User{} = current_user),
+    do: get_familiar_followers_query(user, current_user, nil)
+
+  @spec get_familiar_followers(User.t(), User.t(), pos_integer() | nil) :: {:ok, list(User.t())}
+  def get_familiar_followers(%User{} = user, %User{} = current_user, page \\ nil) do
+    user
+    |> get_familiar_followers_query(current_user, page)
+    |> Repo.all()
+  end
+
   def increase_note_count(%User{} = user) do
     User
     |> where(id: ^user.id)

lib/pleroma/web/api_spec/operations/account_operation.ex

@@ -11,6 +11,7 @@ defmodule Pleroma.Web.ApiSpec.AccountOperation do
   alias Pleroma.Web.ApiSpec.Schemas.ActorType
   alias Pleroma.Web.ApiSpec.Schemas.ApiError
   alias Pleroma.Web.ApiSpec.Schemas.BooleanLike
+  alias Pleroma.Web.ApiSpec.Schemas.FlakeID
   alias Pleroma.Web.ApiSpec.Schemas.List
   alias Pleroma.Web.ApiSpec.Schemas.Status
   alias Pleroma.Web.ApiSpec.Schemas.VisibilityScope
@@ -513,6 +514,47 @@ def identity_proofs_operation do
     }
   end
 
+  def familiar_followers_operation do
+    %Operation{
+      tags: ["Retrieve account information"],
+      summary: "Followers you know",
+      operationId: "AccountController.relationships",
+      description: "Returns followers of given account you know.",
+      security: [%{"oAuth" => ["read:follows"]}],
+      parameters: [
+        Operation.parameter(
+          :id,
+          :query,
+          %Schema{
+            oneOf: [%Schema{type: :array, items: %Schema{type: :string}}, %Schema{type: :string}]
+          },
+          "Account IDs",
+          example: "123"
+        )
+      ],
+      responses: %{
+        200 =>
+          Operation.response("Accounts", "application/json", %Schema{
+            title: "ArrayOfAccounts",
+            type: :array,
+            items: %Schema{
+              title: "Account",
+              type: :object,
+              properties: %{
+                id: FlakeID,
+                accounts: %Schema{
+                  title: "ArrayOfAccounts",
+                  type: :array,
+                  items: Account,
+                  example: [Account.schema().example]
+                }
+              }
+            }
+          })
+      }
+    }
+  end
+
   defp create_request do
     %Schema{
       title: "AccountCreateRequest",

lib/pleroma/web/mastodon_api/controllers/account_controller.ex

@@ -72,7 +72,10 @@ defmodule Pleroma.Web.MastodonAPI.AccountController do
     %{scopes: ["follow", "write:blocks"]} when action in [:block, :unblock]
   )
 
-  plug(OAuthScopesPlug, %{scopes: ["read:follows"]} when action == :relationships)
+  plug(
+    OAuthScopesPlug,
+    %{scopes: ["read:follows"]} when action in [:relationships, :familiar_followers]
+  )
 
   plug(
     OAuthScopesPlug,
@@ -629,6 +632,35 @@ def endorsements(%{assigns: %{user: user}} = conn, params) do
     )
   end
 
+  @doc "GET /api/v1/accounts/familiar_followers"
+  def familiar_followers(
+        %{assigns: %{user: user}, private: %{open_api_spex: %{params: %{id: id}}}} = conn,
+        _id
+      ) do
+    users =
+      User.get_all_by_ids(List.wrap(id))
+      |> Enum.map(&%{id: &1.id, accounts: get_familiar_followers(&1, user)})
+
+    conn
+    |> render("familiar_followers.json",
+      for: user,
+      users: users,
+      as: :user
+    )
+  end
+
+  defp get_familiar_followers(%{id: id} = user, %{id: id}) do
+    User.get_familiar_followers(user, user)
+  end
+
+  defp get_familiar_followers(%{hide_followers: true}, _current_user) do
+    []
+  end
+
+  defp get_familiar_followers(user, current_user) do
+    User.get_familiar_followers(user, current_user)
+  end
+
   @doc "GET /api/v1/identity_proofs"
   def identity_proofs(conn, params), do: MastodonAPIController.empty_array(conn, params)
 end

lib/pleroma/web/mastodon_api/views/account_view.ex

@@ -193,6 +193,25 @@ def render("relationships.json", %{user: user, targets: targets} = opts) do
     render_many(targets, AccountView, "relationship.json", render_opts)
   end
 
+  def render("familiar_followers.json", %{users: users} = opts) do
+    opts =
+      opts
+      |> Map.merge(%{as: :user})
+      |> Map.delete(:users)
+
+    users
+    |> render_many(AccountView, "familiar_followers.json", opts)
+  end
+
+  def render("familiar_followers.json", %{user: %{id: id, accounts: accounts}} = opts) do
+    accounts =
+      accounts
+      |> render_many(AccountView, "show.json", opts)
+      |> Enum.filter(&Enum.any?/1)
+
+    %{id: id, accounts: accounts}
+  end
+
   defp do_render("show.json", %{user: user} = opts) do
     self = opts[:for] == user
 

lib/pleroma/web/router.ex

@@ -633,6 +633,7 @@ defmodule Pleroma.Web.Router do
     patch("/accounts/update_credentials", AccountController, :update_credentials)
 
     get("/accounts/relationships", AccountController, :relationships)
+    get("/accounts/familiar_followers", AccountController, :familiar_followers)
     get("/accounts/:id/lists", AccountController, :lists)
     get("/accounts/:id/identity_proofs", AccountController, :identity_proofs)
     get("/endorsements", AccountController, :endorsements)

test/pleroma/user_test.exs

@@ -2894,6 +2894,20 @@ test "should report error on non-existing alias" do
     end
   end
 
+  describe "get_familiar_followers/3" do
+    test "returns familiar followers for a pair of users" do
+      user1 = insert(:user)
+      %{id: id2} = user2 = insert(:user)
+      user3 = insert(:user)
+      _user4 = insert(:user)
+
+      User.follow(user1, user2)
+      User.follow(user2, user3)
+
+      assert [%{id: ^id2}] = User.get_familiar_followers(user3, user1)
+    end
+  end
+
   describe "account endorsements" do
     test "it pins people" do
       user = insert(:user)

test/pleroma/web/mastodon_api/controllers/account_controller_test.exs

@@ -2172,6 +2172,55 @@ test "max pinned accounts", %{user: user, conn: conn} do
     end
   end
 
+  describe "familiar followers" do
+    setup do: oauth_access(["read:follows"])
+
+    test "fetch user familiar followers", %{user: user, conn: conn} do
+      %{id: id1} = other_user1 = insert(:user)
+      %{id: id2} = other_user2 = insert(:user)
+      _ = insert(:user)
+
+      User.follow(user, other_user1)
+      User.follow(other_user1, other_user2)
+
+      assert [%{"accounts" => [%{"id" => ^id1}], "id" => ^id2}] =
+               conn
+               |> put_req_header("content-type", "application/json")
+               |> get("/api/v1/accounts/familiar_followers?id[]=#{id2}")
+               |> json_response_and_validate_schema(200)
+    end
+
+    test "returns empty array if followers are hidden", %{user: user, conn: conn} do
+      other_user1 = insert(:user, hide_follows: true)
+      %{id: id2} = other_user2 = insert(:user)
+      _ = insert(:user)
+
+      User.follow(user, other_user1)
+      User.follow(other_user1, other_user2)
+
+      assert [%{"accounts" => [], "id" => ^id2}] =
+               conn
+               |> put_req_header("content-type", "application/json")
+               |> get("/api/v1/accounts/familiar_followers?id[]=#{id2}")
+               |> json_response_and_validate_schema(200)
+    end
+
+    test "it respects hide_followers", %{user: user, conn: conn} do
+      other_user1 = insert(:user)
+      %{id: id2} = other_user2 = insert(:user, hide_followers: true)
+      _ = insert(:user)
+
+      User.follow(user, other_user1)
+      User.follow(other_user1, other_user2)
+
+      assert [%{"accounts" => [], "id" => ^id2}] =
+               conn
+               |> put_req_header("content-type", "application/json")
+               |> get("/api/v1/accounts/familiar_followers?id[]=#{id2}")
+               |> json_response_and_validate_schema(200)
+    end
+  end
+
   describe "remove from followers" do
     setup do: oauth_access(["follow"])