class CancerRegistryReportingTestKit::HdeaGenerator::TerminologyBindingMetadataExtractor

def element_has_fixed_value?(element)
  case element.type.first.code
  when 'Quantity'
    code = profile_elements.find { |e| e.path == "#{element.path}.code" }
    system = profile_elements.find { |e| e.path == "#{element.path}.system" }
    code&.fixedCode || system&.fixedUri
  when 'code'
    element.fixedCode.present?
  end
end

def element_has_optional_binding_slice?(element)
  element.sliceName.present? && element.min.zero?
end

def element_terminology_bindings
  profile_elements_with_bindings.map do |element|
    binding = {
      type: element.type.first.code,
      strength: element.binding.strength,
      # Goal.target.detail has an unbound binding
      system: element.binding.valueSet&.split('|')&.first,
      path: element.path.gsub('[x]', '').gsub("#{resource}.", '')
    }
    binding[:required_binding_slice] = true if element.sliceName.present? && element.min.positive?
    binding
  end
end

def extension_profile_elements
  profile_elements
    .select { |element| element.type&.first&.code == 'Extension' }
    .select { |element| extension_profile_url(element).present? }
end

def extension_profile_url(extension)
  extension.type.first.profile&.first
end

def extension_terminology_bindings
  extension_profile_elements
    .flat_map do |extension_profile_element|
      url = extension_profile_url(extension_profile_element)
      extension = ig_resources.profile_by_url(url)
      # TODO: Temporaray fix for extension defined out of US Core. FI-1623
      next if extension.nil?
      elements = extension.snapshot.element
      elements_with_bindings = elements.select do |element|
        element.binding.present? && !element.id.include?('Extension.extension')
      end
      elements_with_bindings.map do |element|
        {
          type: element.type.first.code,
          strength: element.binding.strength,
          system: element.binding.valueSet&.split('|')&.first,
          path: element.path.gsub('[x]', '').gsub('Extension.', ''),
          extensions: [url]
        }
      end + nested_extension_terminology_bindings(elements, url)
    end
end

def initialize(profile_elements, ig_resources, resource)
  self.profile_elements = profile_elements
  self.ig_resources = ig_resources
  self.resource = resource
end

def nested_extension_terminology_bindings(elements, extension_url)
  nested_extensions = elements.select { |element| element.path == 'Extension.extension' }
  nested_extensions.flat_map do |nested_extension|
    nested_extension_element = elements.find { |element| element.id == "#{nested_extension.id}.url" }
    next unless nested_extension_element.present?
    nested_extension_url = nested_extension_element.fixedUri
    nested_elements_with_bindings = elements.select do |element|
      element.id.include?(nested_extension.id) && element.binding.present?
    end
    nested_elements_with_bindings.map do |element|
      {
        type: element.type.first.code,
        strength: element.binding.strength,
        system: element.binding.valueSet&.split('|')&.first,
        path: element.path.gsub('[x]', '').gsub('Extension.extension.', ''),
        extensions: [extension_url, nested_extension_url]
      }
    end
  end
end

def profile_elements_with_bindings
  profile_elements
    .select { |element| element.binding.present? && element.binding.strength == 'required' }
    .reject { |element| element_has_fixed_value?(element) || element_has_optional_binding_slice?(element) }
end

def terminology_bindings
  (element_terminology_bindings + extension_terminology_bindings).compact
  # add_terminology_bindings_from_extensions
  # profile_elements.select { |element| element.type&.first&.code == 'Extension' }
  #   .each { |extension| add_terminology_bindings_from_extension(extension) }
end