First

2 files changed, 758 insertions, 0 deletions

diff --git a/lib/pleroma/web/common_api/activity_draft.ex b/lib/pleroma/web/common_api/activity_draft.ex
new file mode 100644
index 0000000..9af635d
--- /dev/null
+++ b/lib/pleroma/web/common_api/activity_draft.ex
@@ -0,0 +1,273 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.CommonAPI.ActivityDraft do
+  alias Pleroma.Activity
+  alias Pleroma.Conversation.Participation
+  alias Pleroma.Object
+  alias Pleroma.Web.ActivityPub.Builder
+  alias Pleroma.Web.CommonAPI
+  alias Pleroma.Web.CommonAPI.Utils
+
+  import Pleroma.Web.Gettext
+
+  defstruct valid?: true,
+            errors: [],
+            user: nil,
+            params: %{},
+            status: nil,
+            summary: nil,
+            full_payload: nil,
+            attachments: [],
+            in_reply_to: nil,
+            in_reply_to_conversation: nil,
+            visibility: nil,
+            expires_at: nil,
+            extra: nil,
+            emoji: %{},
+            content_html: nil,
+            mentions: [],
+            tags: [],
+            to: [],
+            cc: [],
+            context: nil,
+            sensitive: false,
+            object: nil,
+            preview?: false,
+            changes: %{}
+
+  def new(user, params) do
+    %__MODULE__{user: user}
+    |> put_params(params)
+  end
+
+  def create(user, params) do
+    user
+    |> new(params)
+    |> status()
+    |> summary()
+    |> with_valid(&attachments/1)
+    |> full_payload()
+    |> expires_at()
+    |> poll()
+    |> with_valid(&in_reply_to/1)
+    |> with_valid(&in_reply_to_conversation/1)
+    |> with_valid(&visibility/1)
+    |> content()
+    |> with_valid(&to_and_cc/1)
+    |> with_valid(&context/1)
+    |> sensitive()
+    |> with_valid(&object/1)
+    |> preview?()
+    |> with_valid(&changes/1)
+    |> validate()
+  end
+
+  def listen(user, params) do
+    user
+    |> new(params)
+    |> visibility()
+    |> to_and_cc()
+    |> context()
+    |> listen_object()
+    |> with_valid(&changes/1)
+    |> validate()
+  end
+
+  defp listen_object(draft) do
+    object =
+      draft.params
+      |> Map.take([:album, :artist, :title, :length])
+      |> Map.new(fn {key, value} -> {to_string(key), value} end)
+      |> Map.put("type", "Audio")
+      |> Map.put("to", draft.to)
+      |> Map.put("cc", draft.cc)
+      |> Map.put("actor", draft.user.ap_id)
+
+    %__MODULE__{draft | object: object}
+  end
+
+  defp put_params(draft, params) do
+    params = Map.put_new(params, :in_reply_to_status_id, params[:in_reply_to_id])
+    %__MODULE__{draft | params: params}
+  end
+
+  defp status(%{params: %{status: status}} = draft) do
+    %__MODULE__{draft | status: String.trim(status)}
+  end
+
+  defp summary(%{params: params} = draft) do
+    %__MODULE__{draft | summary: Map.get(params, :spoiler_text, "")}
+  end
+
+  defp full_payload(%{status: status, summary: summary} = draft) do
+    full_payload = String.trim(status <> summary)
+
+    case Utils.validate_character_limit(full_payload, draft.attachments) do
+      :ok -> %__MODULE__{draft | full_payload: full_payload}
+      {:error, message} -> add_error(draft, message)
+    end
+  end
+
+  defp attachments(%{params: params} = draft) do
+    attachments = Utils.attachments_from_ids(params)
+    draft = %__MODULE__{draft | attachments: attachments}
+
+    case Utils.validate_attachments_count(attachments) do
+      :ok -> draft
+      {:error, message} -> add_error(draft, message)
+    end
+  end
+
+  defp in_reply_to(%{params: %{in_reply_to_status_id: ""}} = draft), do: draft
+
+  defp in_reply_to(%{params: %{in_reply_to_status_id: id}} = draft) when is_binary(id) do
+    %__MODULE__{draft | in_reply_to: Activity.get_by_id(id)}
+  end
+
+  defp in_reply_to(%{params: %{in_reply_to_status_id: %Activity{} = in_reply_to}} = draft) do
+    %__MODULE__{draft | in_reply_to: in_reply_to}
+  end
+
+  defp in_reply_to(draft), do: draft
+
+  defp in_reply_to_conversation(draft) do
+    in_reply_to_conversation = Participation.get(draft.params[:in_reply_to_conversation_id])
+    %__MODULE__{draft | in_reply_to_conversation: in_reply_to_conversation}
+  end
+
+  defp visibility(%{params: params} = draft) do
+    case CommonAPI.get_visibility(params, draft.in_reply_to, draft.in_reply_to_conversation) do
+      {visibility, "direct"} when visibility != "direct" ->
+        add_error(draft, dgettext("errors", "The message visibility must be direct"))
+
+      {visibility, _} ->
+        %__MODULE__{draft | visibility: visibility}
+    end
+  end
+
+  defp expires_at(draft) do
+    case CommonAPI.check_expiry_date(draft.params[:expires_in]) do
+      {:ok, expires_at} -> %__MODULE__{draft | expires_at: expires_at}
+      {:error, message} -> add_error(draft, message)
+    end
+  end
+
+  defp poll(draft) do
+    case Utils.make_poll_data(draft.params) do
+      {:ok, {poll, poll_emoji}} ->
+        %__MODULE__{draft | extra: poll, emoji: Map.merge(draft.emoji, poll_emoji)}
+
+      {:error, message} ->
+        add_error(draft, message)
+    end
+  end
+
+  defp content(draft) do
+    {content_html, mentioned_users, tags} = Utils.make_content_html(draft)
+
+    mentions =
+      mentioned_users
+      |> Enum.map(fn {_, mentioned_user} -> mentioned_user.ap_id end)
+      |> Utils.get_addressed_users(draft.params[:to])
+
+    %__MODULE__{draft | content_html: content_html, mentions: mentions, tags: tags}
+  end
+
+  defp to_and_cc(draft) do
+    {to, cc} = Utils.get_to_and_cc(draft)
+    %__MODULE__{draft | to: to, cc: cc}
+  end
+
+  defp context(draft) do
+    context = Utils.make_context(draft.in_reply_to, draft.in_reply_to_conversation)
+    %__MODULE__{draft | context: context}
+  end
+
+  defp sensitive(draft) do
+    sensitive = draft.params[:sensitive]
+    %__MODULE__{draft | sensitive: sensitive}
+  end
+
+  defp object(draft) do
+    emoji = Map.merge(Pleroma.Emoji.Formatter.get_emoji_map(draft.full_payload), draft.emoji)
+
+    # Sometimes people create posts with subject containing emoji,
+    # since subjects are usually copied this will result in a broken
+    # subject when someone replies from an instance that does not have
+    # the emoji or has it under different shortcode. This is an attempt
+    # to mitigate this by copying emoji from inReplyTo if they are present
+    # in the subject.
+    summary_emoji =
+      with %Activity{} <- draft.in_reply_to,
+           %Object{data: %{"tag" => [_ | _] = tag}} <- Object.normalize(draft.in_reply_to) do
+        Enum.reduce(tag, %{}, fn
+          %{"type" => "Emoji", "name" => name, "icon" => %{"url" => url}}, acc ->
+            if String.contains?(draft.summary, name) do
+              Map.put(acc, name, url)
+            else
+              acc
+            end
+
+          _, acc ->
+            acc
+        end)
+      else
+        _ -> %{}
+      end
+
+    emoji = Map.merge(emoji, summary_emoji)
+
+    {:ok, note_data, _meta} = Builder.note(draft)
+
+    object =
+      note_data
+      |> Map.put("emoji", emoji)
+      |> Map.put("source", %{
+        "content" => draft.status,
+        "mediaType" => Utils.get_content_type(draft.params[:content_type])
+      })
+      |> Map.put("generator", draft.params[:generator])
+
+    %__MODULE__{draft | object: object}
+  end
+
+  defp preview?(draft) do
+    preview? = Pleroma.Web.Utils.Params.truthy_param?(draft.params[:preview])
+    %__MODULE__{draft | preview?: preview?}
+  end
+
+  defp changes(draft) do
+    direct? = draft.visibility == "direct"
+    additional = %{"cc" => draft.cc, "directMessage" => direct?}
+
+    additional =
+      case draft.expires_at do
+        %DateTime{} = expires_at -> Map.put(additional, "expires_at", expires_at)
+        _ -> additional
+      end
+
+    changes =
+      %{
+        to: draft.to,
+        actor: draft.user,
+        context: draft.context,
+        object: draft.object,
+        additional: additional
+      }
+      |> Utils.maybe_add_list_data(draft.user, draft.visibility)
+
+    %__MODULE__{draft | changes: changes}
+  end
+
+  defp with_valid(%{valid?: true} = draft, func), do: func.(draft)
+  defp with_valid(draft, _func), do: draft
+
+  defp add_error(draft, message) do
+    %__MODULE__{draft | valid?: false, errors: [message | draft.errors]}
+  end
+
+  defp validate(%{valid?: true} = draft), do: {:ok, draft}
+  defp validate(%{errors: [message | _]}), do: {:error, message}
+end
diff --git a/lib/pleroma/web/common_api/utils.ex b/lib/pleroma/web/common_api/utils.ex
new file mode 100644
index 0000000..ff08143
--- /dev/null
+++ b/lib/pleroma/web/common_api/utils.ex
@@ -0,0 +1,485 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.CommonAPI.Utils do
+  import Pleroma.Web.Gettext
+
+  alias Calendar.Strftime
+  alias Pleroma.Activity
+  alias Pleroma.Config
+  alias Pleroma.Conversation.Participation
+  alias Pleroma.Formatter
+  alias Pleroma.Object
+  alias Pleroma.Repo
+  alias Pleroma.User
+  alias Pleroma.Web.ActivityPub.Utils
+  alias Pleroma.Web.ActivityPub.Visibility
+  alias Pleroma.Web.CommonAPI.ActivityDraft
+  alias Pleroma.Web.MediaProxy
+  alias Pleroma.Web.Plugs.AuthenticationPlug
+  alias Pleroma.Web.Utils.Params
+
+  require Logger
+  require Pleroma.Constants
+
+  def attachments_from_ids(%{media_ids: ids, descriptions: desc}) do
+    attachments_from_ids_descs(ids, desc)
+  end
+
+  def attachments_from_ids(%{media_ids: ids}) do
+    attachments_from_ids_no_descs(ids)
+  end
+
+  def attachments_from_ids(_), do: []
+
+  def attachments_from_ids_no_descs([]), do: []
+
+  def attachments_from_ids_no_descs(ids) do
+    Enum.map(ids, fn media_id ->
+      case get_attachment(media_id) do
+        %Object{data: data} -> data
+        _ -> nil
+      end
+    end)
+    |> Enum.reject(&is_nil/1)
+  end
+
+  def attachments_from_ids_descs([], _), do: []
+
+  def attachments_from_ids_descs(ids, descs_str) do
+    {_, descs} = Jason.decode(descs_str)
+
+    Enum.map(ids, fn media_id ->
+      with %Object{data: data} <- get_attachment(media_id) do
+        Map.put(data, "name", descs[media_id])
+      end
+    end)
+    |> Enum.reject(&is_nil/1)
+  end
+
+  defp get_attachment(media_id) do
+    Repo.get(Object, media_id)
+  end
+
+  @spec get_to_and_cc(ActivityDraft.t()) :: {list(String.t()), list(String.t())}
+
+  def get_to_and_cc(%{in_reply_to_conversation: %Participation{} = participation}) do
+    participation = Repo.preload(participation, :recipients)
+    {Enum.map(participation.recipients, & &1.ap_id), []}
+  end
+
+  def get_to_and_cc(%{visibility: visibility} = draft) when visibility in ["public", "local"] do
+    to =
+      case visibility do
+        "public" -> [Pleroma.Constants.as_public() | draft.mentions]
+        "local" -> [Utils.as_local_public() | draft.mentions]
+      end
+
+    cc = [draft.user.follower_address]
+
+    if draft.in_reply_to do
+      {Enum.uniq([draft.in_reply_to.data["actor"] | to]), cc}
+    else
+      {to, cc}
+    end
+  end
+
+  def get_to_and_cc(%{visibility: "unlisted"} = draft) do
+    to = [draft.user.follower_address | draft.mentions]
+    cc = [Pleroma.Constants.as_public()]
+
+    if draft.in_reply_to do
+      {Enum.uniq([draft.in_reply_to.data["actor"] | to]), cc}
+    else
+      {to, cc}
+    end
+  end
+
+  def get_to_and_cc(%{visibility: "private"} = draft) do
+    {to, cc} = get_to_and_cc(struct(draft, visibility: "direct"))
+    {[draft.user.follower_address | to], cc}
+  end
+
+  def get_to_and_cc(%{visibility: "direct"} = draft) do
+    # If the OP is a DM already, add the implicit actor.
+    if draft.in_reply_to && Visibility.is_direct?(draft.in_reply_to) do
+      {Enum.uniq([draft.in_reply_to.data["actor"] | draft.mentions]), []}
+    else
+      {draft.mentions, []}
+    end
+  end
+
+  def get_to_and_cc(%{visibility: {:list, _}, mentions: mentions}), do: {mentions, []}
+
+  def get_addressed_users(_, to) when is_list(to) do
+    User.get_ap_ids_by_nicknames(to)
+  end
+
+  def get_addressed_users(mentioned_users, _), do: mentioned_users
+
+  def maybe_add_list_data(activity_params, user, {:list, list_id}) do
+    case Pleroma.List.get(list_id, user) do
+      %Pleroma.List{} = list ->
+        activity_params
+        |> put_in([:additional, "bcc"], [list.ap_id])
+        |> put_in([:additional, "listMessage"], list.ap_id)
+        |> put_in([:object, "listMessage"], list.ap_id)
+
+      _ ->
+        activity_params
+    end
+  end
+
+  def maybe_add_list_data(activity_params, _, _), do: activity_params
+
+  def make_poll_data(%{"poll" => %{"expires_in" => expires_in}} = data)
+      when is_binary(expires_in) do
+    # In some cases mastofe sends out strings instead of integers
+    data
+    |> put_in(["poll", "expires_in"], String.to_integer(expires_in))
+    |> make_poll_data()
+  end
+
+  def make_poll_data(%{poll: %{options: options, expires_in: expires_in}} = data)
+      when is_list(options) do
+    limits = Config.get([:instance, :poll_limits])
+
+    with :ok <- validate_poll_expiration(expires_in, limits),
+         :ok <- validate_poll_options_amount(options, limits),
+         :ok <- validate_poll_options_length(options, limits) do
+      {option_notes, emoji} =
+        Enum.map_reduce(options, %{}, fn option, emoji ->
+          note = %{
+            "name" => option,
+            "type" => "Note",
+            "replies" => %{"type" => "Collection", "totalItems" => 0}
+          }
+
+          {note, Map.merge(emoji, Pleroma.Emoji.Formatter.get_emoji_map(option))}
+        end)
+
+      end_time =
+        DateTime.utc_now()
+        |> DateTime.add(expires_in)
+        |> DateTime.to_iso8601()
+
+      key = if Params.truthy_param?(data.poll[:multiple]), do: "anyOf", else: "oneOf"
+      poll = %{"type" => "Question", key => option_notes, "closed" => end_time}
+
+      {:ok, {poll, emoji}}
+    end
+  end
+
+  def make_poll_data(%{"poll" => poll}) when is_map(poll) do
+    {:error, "Invalid poll"}
+  end
+
+  def make_poll_data(_data) do
+    {:ok, {%{}, %{}}}
+  end
+
+  defp validate_poll_options_amount(options, %{max_options: max_options}) do
+    if Enum.count(options) > max_options do
+      {:error, "Poll can't contain more than #{max_options} options"}
+    else
+      :ok
+    end
+  end
+
+  defp validate_poll_options_length(options, %{max_option_chars: max_option_chars}) do
+    if Enum.any?(options, &(String.length(&1) > max_option_chars)) do
+      {:error, "Poll options cannot be longer than #{max_option_chars} characters each"}
+    else
+      :ok
+    end
+  end
+
+  defp validate_poll_expiration(expires_in, %{min_expiration: min, max_expiration: max}) do
+    cond do
+      expires_in > max -> {:error, "Expiration date is too far in the future"}
+      expires_in < min -> {:error, "Expiration date is too soon"}
+      true -> :ok
+    end
+  end
+
+  def make_content_html(%ActivityDraft{} = draft) do
+    attachment_links =
+      draft.params
+      |> Map.get("attachment_links", Config.get([:instance, :attachment_links]))
+      |> Params.truthy_param?()
+
+    content_type = get_content_type(draft.params[:content_type])
+
+    options =
+      if draft.visibility == "direct" && Config.get([:instance, :safe_dm_mentions]) do
+        [safe_mention: true]
+      else
+        []
+      end
+
+    draft.status
+    |> format_input(content_type, options)
+    |> maybe_add_attachments(draft.attachments, attachment_links)
+  end
+
+  def get_content_type(content_type) do
+    if Enum.member?(Config.get([:instance, :allowed_post_formats]), content_type) do
+      content_type
+    else
+      "text/plain"
+    end
+  end
+
+  def make_context(_, %Participation{} = participation) do
+    Repo.preload(participation, :conversation).conversation.ap_id
+  end
+
+  def make_context(%Activity{data: %{"context" => context}}, _), do: context
+  def make_context(_, _), do: Utils.generate_context_id()
+
+  def maybe_add_attachments(parsed, _attachments, false = _no_links), do: parsed
+
+  def maybe_add_attachments({text, mentions, tags}, attachments, _no_links) do
+    text = add_attachments(text, attachments)
+    {text, mentions, tags}
+  end
+
+  def add_attachments(text, attachments) do
+    attachment_text = Enum.map(attachments, &build_attachment_link/1)
+    Enum.join([text | attachment_text], "<br>")
+  end
+
+  defp build_attachment_link(%{"url" => [%{"href" => href} | _]} = attachment) do
+    name = attachment["name"] || URI.decode(Path.basename(href))
+    href = MediaProxy.url(href)
+    "<a href=\"#{href}\" class='attachment'>#{shortname(name)}</a>"
+  end
+
+  defp build_attachment_link(_), do: ""
+
+  def format_input(text, format, options \\ [])
+
+  @doc """
+  Formatting text to plain text, BBCode, HTML, or Markdown
+  """
+  def format_input(text, "text/plain", options) do
+    text
+    |> Formatter.html_escape("text/plain")
+    |> Formatter.linkify(options)
+    |> (fn {text, mentions, tags} ->
+          {String.replace(text, ~r/\r?\n/, "<br>"), mentions, tags}
+        end).()
+  end
+
+  def format_input(text, "text/bbcode", options) do
+    text
+    |> String.replace(~r/\r/, "")
+    |> Formatter.html_escape("text/plain")
+    |> BBCode.to_html()
+    |> (fn {:ok, html} -> html end).()
+    |> Formatter.linkify(options)
+  end
+
+  def format_input(text, "text/html", options) do
+    text
+    |> Formatter.html_escape("text/html")
+    |> Formatter.linkify(options)
+  end
+
+  def format_input(text, "text/markdown", options) do
+    text
+    |> Formatter.mentions_escape(options)
+    |> Formatter.markdown_to_html()
+    |> Formatter.linkify(options)
+    |> Formatter.html_escape("text/html")
+  end
+
+  def format_naive_asctime(date) do
+    date |> DateTime.from_naive!("Etc/UTC") |> format_asctime
+  end
+
+  def format_asctime(date) do
+    Strftime.strftime!(date, "%a %b %d %H:%M:%S %z %Y")
+  end
+
+  def date_to_asctime(date) when is_binary(date) do
+    with {:ok, date, _offset} <- DateTime.from_iso8601(date) do
+      format_asctime(date)
+    else
+      _e ->
+        Logger.warn("Date #{date} in wrong format, must be ISO 8601")
+        ""
+    end
+  end
+
+  def date_to_asctime(date) do
+    Logger.warn("Date #{date} in wrong format, must be ISO 8601")
+    ""
+  end
+
+  def to_masto_date(%NaiveDateTime{} = date) do
+    date
+    |> NaiveDateTime.to_iso8601()
+    |> String.replace(~r/(\.\d+)?$/, ".000Z", global: false)
+  end
+
+  def to_masto_date(date) when is_binary(date) do
+    with {:ok, date} <- NaiveDateTime.from_iso8601(date) do
+      to_masto_date(date)
+    else
+      _ -> ""
+    end
+  end
+
+  def to_masto_date(_), do: ""
+
+  defp shortname(name) do
+    with max_length when max_length > 0 <-
+           Config.get([Pleroma.Upload, :filename_display_max_length], 30),
+         true <- String.length(name) > max_length do
+      String.slice(name, 0..max_length) <> "…"
+    else
+      _ -> name
+    end
+  end
+
+  @spec confirm_current_password(User.t(), String.t()) :: {:ok, User.t()} | {:error, String.t()}
+  def confirm_current_password(user, password) do
+    with %User{local: true} = db_user <- User.get_cached_by_id(user.id),
+         true <- AuthenticationPlug.checkpw(password, db_user.password_hash) do
+      {:ok, db_user}
+    else
+      _ -> {:error, dgettext("errors", "Invalid password.")}
+    end
+  end
+
+  def maybe_notify_to_recipients(
+        recipients,
+        %Activity{data: %{"to" => to, "type" => _type}} = _activity
+      ) do
+    recipients ++ to
+  end
+
+  def maybe_notify_to_recipients(recipients, _), do: recipients
+
+  def maybe_notify_mentioned_recipients(
+        recipients,
+        %Activity{data: %{"to" => _to, "type" => type} = data} = activity
+      )
+      when type == "Create" do
+    object = Object.normalize(activity, fetch: false)
+
+    object_data =
+      cond do
+        not is_nil(object) ->
+          object.data
+
+        is_map(data["object"]) ->
+          data["object"]
+
+        true ->
+          %{}
+      end
+
+    tagged_mentions = maybe_extract_mentions(object_data)
+
+    recipients ++ tagged_mentions
+  end
+
+  def maybe_notify_mentioned_recipients(recipients, _), do: recipients
+
+  def maybe_notify_subscribers(
+        recipients,
+        %Activity{data: %{"actor" => actor, "type" => "Create"}} = activity
+      ) do
+    # Do not notify subscribers if author is making a reply
+    with %Object{data: object} <- Object.normalize(activity, fetch: false),
+         nil <- object["inReplyTo"],
+         %User{} = user <- User.get_cached_by_ap_id(actor) do
+      subscriber_ids =
+        user
+        |> User.subscriber_users()
+        |> Enum.filter(&Visibility.visible_for_user?(activity, &1))
+        |> Enum.map(& &1.ap_id)
+
+      recipients ++ subscriber_ids
+    else
+      _e -> recipients
+    end
+  end
+
+  def maybe_notify_subscribers(recipients, _), do: recipients
+
+  def maybe_notify_followers(recipients, %Activity{data: %{"type" => "Move"}} = activity) do
+    with %User{} = user <- User.get_cached_by_ap_id(activity.actor) do
+      user
+      |> User.get_followers()
+      |> Enum.map(& &1.ap_id)
+      |> Enum.concat(recipients)
+    else
+      _e -> recipients
+    end
+  end
+
+  def maybe_notify_followers(recipients, _), do: recipients
+
+  def maybe_extract_mentions(%{"tag" => tag}) do
+    tag
+    |> Enum.filter(fn x -> is_map(x) && x["type"] == "Mention" end)
+    |> Enum.map(fn x -> x["href"] end)
+    |> Enum.uniq()
+  end
+
+  def maybe_extract_mentions(_), do: []
+
+  def make_report_content_html(nil), do: {:ok, {nil, [], []}}
+
+  def make_report_content_html(comment) do
+    max_size = Config.get([:instance, :max_report_comment_size], 1000)
+
+    if String.length(comment) <= max_size do
+      {:ok, format_input(comment, "text/plain")}
+    else
+      {:error,
+       dgettext("errors", "Comment must be up to %{max_size} characters", max_size: max_size)}
+    end
+  end
+
+  def get_report_statuses(%User{ap_id: actor}, %{status_ids: status_ids})
+      when is_list(status_ids) do
+    {:ok, Activity.all_by_actor_and_id(actor, status_ids)}
+  end
+
+  def get_report_statuses(_, _), do: {:ok, nil}
+
+  def validate_character_limit("" = _full_payload, [] = _attachments) do
+    {:error, dgettext("errors", "Cannot post an empty status without attachments")}
+  end
+
+  def validate_character_limit(full_payload, _attachments) do
+    limit = Config.get([:instance, :limit])
+    length = String.length(full_payload)
+
+    if length <= limit do
+      :ok
+    else
+      {:error, dgettext("errors", "The status is over the character limit")}
+    end
+  end
+
+  def validate_attachments_count([] = _attachments) do
+    :ok
+  end
+
+  def validate_attachments_count(attachments) do
+    limit = Config.get([:instance, :max_media_attachments])
+    count = length(attachments)
+
+    if count <= limit do
+      :ok
+    else
+      {:error, dgettext("errors", "Too many attachments")}
+    end
+  end
+end