module RSpec::Puppet
  module ManifestMatchers
    class CountGeneric
      DEFAULT_RESOURCES = [
        'Class[main]',
        'Class[Settings]',
        'Stage[main]',
      ].freeze

      attr_reader :resource_type

      def initialize(type, count, *method)
        if type.nil?
          @type = method[0].to_s.gsub(/^have_(.+)_resource_count$/, '\1')
        else
          @type = type
        end
        @resource_type = referenced_type(@type)
        @expected_number = count.to_i
      end

      def matches?(catalogue)
        @catalogue = catalogue.call

        resources = @catalogue.resources.reject do |res|
          DEFAULT_RESOURCES.include?(res.ref)
        end

        @actual_number = if @type == 'resource'
                           resources.count do |res|
                             !['Class', 'Node'].include?(res.type)
                           end
                         else
                           resources.count do |res|
                             res.type == @resource_type
                           end
                         end

        @actual_number == @expected_number
      end

      def description
        desc = []

        desc << "contain exactly #{@expected_number}"
        if @type == "class"
          desc << "#{@expected_number == 1 ? "class" : "classes" }"
        else
          unless @type == "resource"
            desc << "#{@resource_type}"
          end
          desc << "#{@expected_number == 1 ? "resource" : "resources" }"
        end

        desc.join(" ")
      end

      def failure_message
        "expected that the catalogue would " + description + " but it contains #{@actual_number}"
      end

      def failure_message_when_negated
        "expected that the catalogue would not " + description + " but it does"
      end

      def supports_block_expectations
        true
      end

      def supports_value_expectations
        true
      end

    private

      def referenced_type(type)
        type.split('__').map { |r| r.capitalize }.join('::')
      end
    end

    def have_class_count(count)
      RSpec::Puppet::ManifestMatchers::CountGeneric.new('class', count)
    end

    def have_resource_count(count)
      RSpec::Puppet::ManifestMatchers::CountGeneric.new('resource', count)
    end
  end
end