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

app/models/link.rb

@@ -0,0 +1,51 @@
+class Link < ApplicationRecord
+  belongs_to :link_category
+  has_rich_text :description_html
+
+  validates :url, :text, presence: true
+  validate :check_url
+  validate :valid_url
+  
+  before_validation :ensure_absolute_url
+
+  def ok?
+    fail_count == 0
+  end
+
+  private
+
+  USER_AGENT = "Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/115.0"
+
+  def check_url(input = url, add_error = true)
+    response = begin
+      Net::HTTP.get_response(URI.parse(input), "User-Agent": USER_AGENT) 
+    rescue Socket::ResolutionError
+      errors.add(:url, :invalid) if add_error
+      return false
+    end
+      
+    case response
+    when Net::HTTPSuccess
+      self.last_check_at = Time.zone.now
+      self.fail_count = 0
+      
+      true
+    when Net::HTTPRedirection
+      check_url(response[:location])
+    else
+      self.last_check_at = Time.zone.now
+      self.fail_count += 1
+      errors.add(:url, :invalid) if add_error
+
+      false
+    end
+  end
+
+  def ensure_absolute_url
+    self.url = "https://#{self.url}" unless self.url.match?(%r{https{0,1}://.*})
+  end
+
+  def valid_url
+    errors.add(:url, :invalid) unless url.match /\A#{URI::regexp(['http', 'https'])}\z/
+  end
+end

app/models/link_category.rb

@@ -0,0 +1,5 @@
+class LinkCategory < ApplicationRecord
+  has_many :links
+  
+  has_rich_text :description_html
+end

app/models/success_criterion.rb

@@ -6,4 +6,10 @@ class SuccessCriterion < ApplicationRecord
   has_rich_text :description_html
 
   belongs_to :element, touch: true
+
+  def level_value
+    return nil unless level
+
+    self.class.levels.values.index_of(level)
+  end
 end