class Airbrake::Rack::User

def self.extract(rack_env)
  # Warden support (including Devise).
  if (warden = rack_env['warden'])
    user = warden.user(run_callbacks: false)
    # Early return to prevent unwanted possible authentication via
    # calling the `current_user` method later.
    # See: https://github.com/airbrake/airbrake/issues/641
    return user ? new(user) : nil
  end
  # Fallback mode (OmniAuth support included). Works only for Rails.
  user = try_current_user(rack_env)
  new(user) if user
end

def self.try_current_user(rack_env)
  controller = rack_env['action_controller.instance']
  return unless controller.respond_to?(:current_user, true)
  return unless [-1, 0].include?(controller.method(:current_user).arity)
  begin
    controller.__send__(:current_user)
  rescue Exception => _e # rubocop:disable Lint/RescueException
    nil
  end
end

def as_json
  user = {}
  user[:id] = try_to_get(:id)
  user[:name] = full_name
  user[:username] = try_to_get(:username)
  user[:email] = try_to_get(:email)
  user = user.delete_if { |_key, val| val.nil? }
  user.empty? ? user : { user: user }
end

def full_name
  # Try to get first and last names. If that fails, try to get just 'name'.
  name = [try_to_get(:first_name), try_to_get(:last_name)].compact.join(' ')
  name.empty? ? try_to_get(:name) : name
end

def initialize(user)
  @user = user
end

def try_to_get(key)
  return unless @user.respond_to?(key)
  # try methods with no arguments or with variable number of arguments,
  # where none of them are required
  return unless @user.method(key).arity.between?(-1, 0)
  String(@user.__send__(key))
end