class ApiController < ApplicationController
  before_action :only_respect_accept_header

  private

  # By default, Rails will ignore the Accept header if it contains a wildcard
  # and assume the client wants HTML (or JS if using XMLHttpRequest). See
  # https://github.com/rails/rails/blob/a807a4f4f95798616a2a85856f77fdfc48da4832/actionpack/lib/action_dispatch/http/mime_negotiation.rb#L171-L173
  #
  # If you don't expect your clients to be browsers, we want to override this
  # and only set the request formats from the Accept header, falling back to
  # the wildcard if it is not present (and therefore respecting our
  # priorities).
  #
  # Note we have to filter down the MIME types to ones Rails understands
  # otherwise it will raise an error when attempting to set formats for the
  # lookup context.
  def only_respect_accept_header
    request.set_header(
      "action_dispatch.request.formats",
      requested_mime_types.select { |type| type.symbol || type.ref == "*/*" }
    )
  end

  def requested_mime_types
    Mime::Type.parse(request.get_header("HTTP_ACCEPT").to_s).presence || [Mime::ALL]
  end
end