module Cany
  class Specification
    class DSL
      def initialize(specification)
        @specification = specification
      end

      def exec(&block)
        instance_eval(&block)
      end

      def self.delegate(*methods)
        methods.each do |method|
          module_eval(<<-EOS, __FILE__, __LINE__)
            def #{method}(*args, &block)
              @specification.send :'#{method}=', *args, &block
            end
            EOS
        end
      end

      delegate :name, :description, :maintainer_name, :maintainer_email, :website, :licence, :version

      # This directive ensures that Cany is used in a specific version. It will pass if the version
      # match or raise an exception if it is an unsupported version.
      # @param version [String] The version constrain the must be satisfied by Cany.
      # @raise Cany::UnsupportedVersion on version mismatch
      def require_cany(version)
        unless Gem::Requirement.create(version).satisfied_by? Gem::Version.new(Cany::VERSION)
          raise UnsupportedVersion.new version
        end
        @specification.cany_version_constraint = version
      end

      # This include the given recipe into the build process.
      # @param [Symbol] name The name of the recipe as symbol.
      def use(name, &block)
        @specification.recipes << Cany::Recipe.from_name(name).new(@specification, &block)
      end

      def build(&block)
        @specification.build = block
      end

      def binary(&block)
        @specification.binary = block
      end

      # @api public
      # Adds a new dependency for the software. See Cany::Dependency for a more
      # abstract description about dependencies
      # See Cany::Mixins::DependMixin for parameter description
      include Mixins::DependMixin
      def depend(*args)
        @specification.dependencies << create_dep(*args)
      end
    end
  end
end