# frozen_string_literal: true

module Zenlish
  module Inflect
    class InflectionTable
      attr_reader :name
      attr_reader :headings
      attr_reader :rules

      def initialize(aName)
        @name = aName
        @headings = []
        @rules = []
      end

      def add_heading(aHeading)
        @headings << aHeading
      end

      def add_rule(aRule)
        @rules << aRule
      end

      def inflect(aLexeme, theConstraints)
        constraints = if theConstraints.nil? || theConstraints.empty?
          Array.new(headings.size) { |_i| nil }
        else
          theConstraints
        end
        err_msg = "Table has #{headings.size} headings, instead of #{constraints.size}"
        raise StandardError, err_msg if constraints.size != headings.size

        actuals = []
        headings.each_with_index do |hd, idx|
          if constraints[idx]
            actuals << constraints[idx]
          else
            actuals << hd.evaluate_for(aLexeme)
          end
        end
        # Hit policy: first
        matching_rule = rules.find do |rule|
          rule.success?(headings, aLexeme, actuals)
        end
        unless matching_rule
          err_msg = "No rule in table covers case: lexeme #{aLexeme}, actuals: #{p actuals}."
          raise StandardError, err_msg
        end
        matching_rule.apply(headings, aLexeme, actuals)
      end

      def all_inflections(aLexeme)
        constraints = Array.new(headings.size) { |_i| nil }
        heading_matches = []
        headings.each_with_index do |hd, _idx|
          heading_matches << hd.all_matches(aLexeme)
        end
        w_forms = nil
        if constraints.size == 1
          all_combos = heading_matches
          w_forms = all_combos.first.map do |item|
            inflect(aLexeme, [item])
          end
        else
          vector1 = heading_matches.shift
          all_combos = vector1.product(*heading_matches)
          w_forms = all_combos.map do |combination|
            inflect(aLexeme, combination)
          end
        end

        w_forms.uniq
      end
    end # class
  end # module
end # module