Move reblogged_by and favourited_by actions out of api/v1/statuses and into unique controllers (#3646)

* Add specs for api statuses routes

* Update favourited_by and reblogged_by api routes

* Move methods into new controllers

* Use load_accounts methods to simplify index actions

* Clean up load_accounts methods

* Clean up link header generation

* Check for link headers in specs

* Remove unused actions from api/v1/statuses controller

* Remove specs for moved actions

1 files changed, 82 insertions, 0 deletions

diff --git a/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb b/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb
new file mode 100644
index 000000000..e58184939
--- /dev/null
+++ b/app/controllers/api/v1/statuses/favourited_by_accounts_controller.rb
@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+class Api::V1::Statuses::FavouritedByAccountsController < Api::BaseController
+  include Authorization
+
+  before_action :authorize_if_got_token
+  before_action :set_status
+  after_action :insert_pagination_headers
+
+  respond_to :json
+
+  def index
+    @accounts = load_accounts
+    render 'api/v1/statuses/accounts'
+  end
+
+  private
+
+  def load_accounts
+    default_accounts.merge(paginated_favourites).to_a
+  end
+
+  def default_accounts
+    Account
+      .includes(:favourites)
+      .references(:favourites)
+      .where(favourites: { status_id: @status.id })
+  end
+
+  def paginated_favourites
+    Favourite.paginate_by_max_id(
+      limit_param(DEFAULT_ACCOUNTS_LIMIT),
+      params[:max_id],
+      params[:since_id]
+    )
+  end
+
+  def insert_pagination_headers
+    set_pagination_headers(next_path, prev_path)
+  end
+
+  def next_path
+    if records_continue?
+      api_v1_status_favourited_by_index_url pagination_params(max_id: pagination_max_id)
+    end
+  end
+
+  def prev_path
+    unless @accounts.empty?
+      api_v1_status_favourited_by_index_url pagination_params(since_id: pagination_since_id)
+    end
+  end
+
+  def pagination_max_id
+    @accounts.last.favourites.last.id
+  end
+
+  def pagination_since_id
+    @accounts.first.favourites.first.id
+  end
+
+  def records_continue?
+    @accounts.size == limit_param(DEFAULT_ACCOUNTS_LIMIT)
+  end
+
+  def set_status
+    @status = Status.find(params[:status_id])
+    authorize @status, :show?
+  rescue Mastodon::NotPermittedError
+    # Reraise in order to get a 404 instead of a 403 error code
+    raise ActiveRecord::RecordNotFound
+  end
+
+  def authorize_if_got_token
+    request_token = Doorkeeper::OAuth::Token.from_request(request, *Doorkeeper.configuration.access_token_methods)
+    doorkeeper_authorize! :read if request_token
+  end
+
+  def pagination_params(core_params)
+    params.permit(:limit).merge(core_params)
+  end
+end