Move complex die methods into themed helpers

lib/games_dice/complex_die.rb

@@ -24,7 +24,9 @@ module GamesDice
   #  d.explain_result # => "[6+5] 11 Success"
   #
   class ComplexDie
-    include GamesDice::ComplexDieHelpers
+    include RollHelpers
+    include ProbabilityHelpers
+    include MinMaxHelpers
 
     # @!visibility private
     # arbitrary limit to speed up probability calculations. It should
@@ -109,17 +111,7 @@ def max
     # 1e-9 at worst.
     # @return [GamesDice::Probabilities] Probability distribution of die.
     def probabilities
-      return @probabilities if @probabilities
-
-      @probabilities = if @rerolls && @maps
-                         GamesDice::Probabilities.from_h(prob_hash_with_rerolls_and_maps)
-                       elsif @rerolls
-                         GamesDice::Probabilities.from_h(recursive_probabilities)
-                       elsif @maps
-                         GamesDice::Probabilities.from_h(prob_hash_with_just_maps)
-                       else
-                         @basic_die.probabilities
-                       end
+      @probabilities ||= calculate_probabilities
     end
 
     # Simulates rolling the die
@@ -134,84 +126,6 @@ def roll(reason = :basic)
 
     private
 
-    def prob_hash_with_rerolls_and_maps
-      reroll_probs = recursive_probabilities
-      prob_hash = {}
-      reroll_probs.each do |v, p|
-        add_mapped_to_prob_hash(prob_hash, v, p)
-      end
-      prob_hash
-    end
-
-    def prob_hash_with_just_maps
-      prob_hash = {}
-      @basic_die.probabilities.each do |v, p|
-        add_mapped_to_prob_hash(prob_hash, v, p)
-      end
-      prob_hash
-    end
-
-    def add_mapped_to_prob_hash(prob_hash, orig_val, prob)
-      mapped_val, = calc_maps(orig_val)
-      prob_hash[mapped_val] ||= 0.0
-      prob_hash[mapped_val] += prob
-    end
-
-    def roll_apply_rerolls
-      return unless @rerolls
-
-      subtracting = false
-      rerolls_remaining = @rerolls.map(&:limit)
-
-      rerolls_loop(subtracting, rerolls_remaining)
-    end
-
-    def rerolls_loop(subtracting, rerolls_remaining)
-      loop do
-        rule_idx = find_matching_reroll_rule(@basic_die.result, @result.rolls.length, rerolls_remaining)
-        break unless rule_idx
-
-        rule = @rerolls[rule_idx]
-        rerolls_remaining[rule_idx] -= 1
-        subtracting = true if rule.type == :reroll_subtract
-        roll_apply_reroll_rule rule, subtracting
-      end
-    end
-
-    def roll_apply_reroll_rule(rule, is_subtracting)
-      # Apply the rule (note reversal for additions, after a subtract)
-      if is_subtracting && rule.type == :reroll_add
-        @result.add_roll(@basic_die.roll, :reroll_subtract)
-      else
-        @result.add_roll(@basic_die.roll, rule.type)
-      end
-    end
-
-    # Find which rule, if any, is being triggered
-    def find_matching_reroll_rule(check_value, num_rolls, rerolls_remaining)
-      @rerolls.zip(rerolls_remaining).find_index do |rule, remaining|
-        next if rule.type == :reroll_subtract && num_rolls > 1
-
-        remaining.positive? && rule.applies?(check_value)
-      end
-    end
-
-    def roll_apply_maps
-      return unless @maps
-
-      m, n = calc_maps(@result.value)
-      @result.apply_map(m, n)
-    end
-
-    def calc_minmax
-      @min_result = probabilities.min
-      @max_result = probabilities.max
-      return if @probabilities_complete
-
-      logical_min, logical_max = logical_minmax
-      @min_result, @max_result = [@min_result, @max_result, logical_min, logical_max].minmax
-    end
-
     def construct_rerolls(rerolls_input)
       check_and_construct rerolls_input, GamesDice::RerollRule, 'rerolls'
     end
@@ -233,70 +147,5 @@ def check_and_construct(input, klass, label)
         end
       end
     end
-
-    def calc_maps(original_value)
-      y = 0
-      n = ''
-      @maps.find do |rule|
-        if (maybe_y = rule.map_from(original_value))
-          y = maybe_y
-          n = rule.mapped_name
-        end
-        maybe_y
-      end
-      [y, n]
-    end
-
-    def minmax_mappings(possible_values)
-      possible_values.map do |x|
-        map_val, = calc_maps(x)
-        map_val
-      end.minmax
-    end
-
-    # This isn't 100% accurate, but does cover most "normal" scenarios, and we're only falling back to it when we have
-    # to. The inaccuracy is that min_result..max_result may contain 'holes' which have extreme map values that cannot
-    # actually occur. In practice it is likely a non-issue unless someone went out of their way to invent a dice scheme
-    # that broke it.
-    def logical_minmax
-      return @basic_die.minmax unless @rerolls || @maps
-      return minmax_mappings(@basic_die.all_values) unless @rerolls
-
-      min_result, max_result = logical_rerolls_minmax
-      return minmax_mappings((min_result..max_result)) if @maps
-
-      [min_result, max_result]
-    end
-
-    def logical_rerolls_minmax
-      min_result = @basic_die.min
-      max_result = @basic_die.max
-      min_subtract = find_minimum_possible_subtract
-      max_add = find_maximum_possible_adds
-      min_result = [min_subtract - max_add, min_subtract - max_result].min if min_subtract
-      [min_result, max_add + max_result]
-    end
-
-    def find_minimum_possible_subtract
-      min_subtract = nil
-      @rerolls.select { |r| r.type == :reroll_subtract }.each do |rule|
-        min_reroll = @basic_die.all_values.select { |v| rule.applies?(v) }.min
-        next unless min_reroll
-
-        min_subtract = [min_reroll, min_subtract].compact.min
-      end
-      min_subtract
-    end
-
-    def find_maximum_possible_adds
-      total_add = 0
-      @rerolls.select { |r| r.type == :reroll_add }.each do |rule|
-        max_reroll = @basic_die.all_values.select { |v| rule.applies?(v) }.max
-        next unless max_reroll
-
-        total_add += max_reroll * rule.limit
-      end
-      total_add
-    end
   end
 end