class Google::Auth::ClientId

def self.from_file(file)
  raise 'File can not be nil.' if file.nil?
  File.open(file.to_s) do |f|
    json = f.read
    config = MultiJson.load(json)
    from_hash(config)
  end
end

def self.from_hash(config)
  raise 'Hash can not be nil.' if config.nil?
  raw_detail = config[INSTALLED_APP] || config[WEB_APP]
  raise MISSING_TOP_LEVEL_ELEMENT_ERROR if raw_detail.nil?
  ClientId.new(raw_detail[CLIENT_ID], raw_detail[CLIENT_SECRET])
end

def initialize(id, secret)
  raise 'Client id can not be nil' if id.nil?
  raise 'Client secret can not be nil' if secret.nil?
  @id = id
  @secret = secret
end