class GlobalID

def self.eager_load!
  super
  require 'global_id/signed_global_id'
end

def ==(other)
  other.is_a?(GlobalID) && @uri == other.uri
end

def app=(app)
  @app = URI::GID.validate_app(app)
end

def create(model, options = {})
  if app = options.fetch(:app) { GlobalID.app }
    params = options.except(:app, :verifier, :for)
    new URI::GID.create(app, model, params), options
  else
    raise ArgumentError, 'An app is required to create a GlobalID. ' \
      'Pass the :app option or set the default GlobalID.app.'
  end
end

def find(gid, options = {})
  parse(gid, options).try(:find, options)
end

def find(options = {})
  Locator.locate self, options
end

def hash
  self.class.hash | @uri.hash
end

def initialize(gid, options = {})
  @uri = gid.is_a?(URI::GID) ? gid : URI::GID.parse(gid)
end

def model_class
  model_name.constantize
end

def parse(gid, options = {})
  gid.is_a?(self) ? gid : new(gid, options)
rescue URI::Error
  parse_encoded_gid(gid, options)
end

def parse_encoded_gid(gid, options)
  new(Base64.urlsafe_decode64(repad_gid(gid)), options) rescue nil
end

def repad_gid(gid)
  padding_chars = gid.length.modulo(4).zero? ? 0 : (4 - gid.length.modulo(4))
  gid + ('=' * padding_chars)
end

def to_param
  # remove the = padding character for a prettier param -- it'll be added back in parse_encoded_gid
  Base64.urlsafe_encode64(to_s).sub(/=+$/, '')
end