module Gameball
  module Utils
    extend self

    def validate(hash, required, optional)
      errors = []
      required.each do |val|
        raise Gameball::GameballError.new("Required key: #{val.to_sym.inspect}") unless hash.has_key?(val.to_sym)
      end
      optional = optional + required
      hash.each_key do |val|
        unless optional.include?(val.to_s)
          raise Gameball::GameballError.new("Unknown key: #{val.to_sym.inspect}. Valid keys are: #{optional.map(&:inspect).join(", ")}")
        end
      end
    end
  end
end