Links, mainly...

app/models/element.rb

@@ -7,4 +7,27 @@ class Element < ApplicationRecord
   has_many :success_criteria, dependent: :destroy
 
   validates :path, :title, presence: true
+
+  # Calculate actual conformity level:
+  # - if a success_criterion has result :failed -> the confirmity_level
+  #   of that success_criterion is not reached.
+  # - the resulting level is the highest readched level
+  #   abeying rule above.
+  def level
+    return nil
+    return nil unless success_criteria.all(&:result)
+
+    min_failed = success_criteria.select(&:failed?).map(&:level).min
+    possible_levels = success_criteria.select(&:passed?).map(&:level).uniq
+
+    return nil if possible_levels.empty?
+
+    puts possible_levels.inspect
+    puts min_failed
+    possible_levels[possible_levels.find_index(min_failed) - 1]
+  end
+
+  def max_level
+    @max_level ||= success_criteria.reject(&:not_applicable?).max(&:level)
+  end
 end