metric.rb

module Metric
  module Formula
    class Nps < Base

    end
  end
end

module Metric
  module Formula
    class AverageScore < Base
      def build

      end

      private

      def build_filters(filters)

      end

    end
  end
end

module Metric
  module Formula
    class Base

    end
  end
end

module Metric
  class Builder
    def initialize(formula, params)
      @formula = formula
      @filters = params[:filters]
      @group_by = params[:group_by]
      @timeseries = params[:timeseries]
    end

    def build
      add_formula(@formula)
      add_filters
      group_by
      with_timeseries
      split_by_date
      self
    end

    private
  end
end

module Metric
  class MetricFactory
    def initialize(type, params)
      @type = type
      @params = params
    end

    def data
      result = builder.execute
      formatter.call(result)
    end

    private

    def formatter
      # check shiich one you need
      Metric::Formatter.new
    end

    def builder
      return @builder if @builder
      @formula =  build_formula(@type, @params[:params])
      @builder = Metric::Builer.new(@formula, builder_params)
    end

    def build_formula(type, formula_params)
      formula_class = "Metric::Formula::#{type.to_s.camelize}" if name.to_sym.in?(BUILTIN_FORMULAE)
      (formula_class || "Metric::Formula::Custom").constantize.new(formula_params)
    end
  end
end

metric = Metric::MetricFactory.new(:nps, params)
metric.data # => already formatted data