module RockConfig
  class Manager
    def initialize(configuration, scanner = Scanner)
      @scanner = scanner.new(configuration)
      @configs = initialize_configs
    end

    def fetch(config_name, environment)
      if config = @configs[config_name]
        if config_for_environment = config[environment]
          return config_for_environment
        else
          raise EnvironmentNotFoundError,
            'Environment "%s" not found for config file "%s"' % [environment, config_name]
        end
      end
    end

    def initialize_configs
      Hash.new do |hash, key|
        if config = @scanner.find(key)
          hash[key] = config
        end
      end
    end
  end
end