akkoma/lib/pleroma/collections/fetcher.ex
2022-07-03 19:36:30 +01:00

77 lines
2.3 KiB
Elixir

# Akkoma: The cooler fediverse server
# Copyright © 2022- Akkoma Authors <https://akkoma.dev/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Akkoma.Collections.Fetcher do
@moduledoc """
Activitypub Collections fetching functions
see: https://www.w3.org/TR/activitystreams-core/#paging
"""
alias Pleroma.Object.Fetcher
alias Pleroma.Config
def fetch_collection_by_ap_id(ap_id) when is_binary(ap_id) do
fetch_collection(ap_id)
end
def fetch_collection(ap_id) when is_binary(ap_id) do
with {:ok, page} <- Fetcher.fetch_and_contain_remote_object_from_id(ap_id) do
{:ok, objects_from_collection(page)}
else
e ->
Logger.error("Could not fetch collection #{ap_id} - #{inspect(e)}")
e
end
end
def fetch_collection(%{"type" => type} = page)
when type in ["Collection", "OrderedCollection"] do
{:ok, objects_from_collection(page)}
end
defp items_in_page(%{"type" => type, "orderedItems" => items})
when is_list(items) and type in ["OrderedCollection", "OrderedCollectionPage"],
do: items
defp items_in_page(%{"type" => type, "items" => items})
when is_list(items) and type in ["Collection", "CollectionPage"],
do: items
defp objects_from_collection(%{"type" => "OrderedCollection", "orderedItems" => items})
when is_list(items),
do: items
defp objects_from_collection(%{"type" => "Collection", "items" => items}) when is_list(items),
do: items
defp objects_from_collection(%{"type" => type, "first" => first})
when is_binary(first) and type in ["Collection", "OrderedCollection"] do
fetch_page_items(first)
end
defp objects_from_collection(%{"type" => type, "first" => %{"id" => id}})
when is_binary(id) and type in ["Collection", "OrderedCollection"] do
fetch_page_items(id)
end
defp fetch_page_items(id, items \\ []) do
if Enum.count(items) >= Config.get([:activitypub, :max_collection_objects]) do
items
else
{:ok, page} = Fetcher.fetch_and_contain_remote_object_from_id(id)
objects = items_in_page(page)
if Enum.count(objects) > 0 do
maybe_next_page(page, items ++ objects)
else
items
end
end
end
defp maybe_next_page(%{"next" => id}, items) when is_binary(id) do
fetch_page_items(id, items)
end
defp maybe_next_page(_, items), do: items
end