class RuboCop::Formatter::JUnitFormatter

def add_failure_to(testcase, offenses, cop_name)
  # One failure per offense. Zero failures is a passing test case,
  # for most surefire/nUnit parsers.
  offenses.each do |offense|
    REXML::Element.new('failure', testcase).tap do |failure|
      failure.attributes['type'] = cop_name
      failure.attributes['message'] = offense.message
      failure.add_text(offense.location.to_s)
    end
  end
end

def add_testcase_element_to_testsuite_element(file, target_offenses, cop)
  REXML::Element.new('testcase', @testsuite).tap do |testcase|
    testcase.attributes['classname'] = classname_attribute_value(file)
    testcase.attributes['name'] = cop.cop_name
    add_failure_to(testcase, target_offenses, cop.cop_name)
  end
end

def classname_attribute_value(file)
  @classname_attribute_value_cache ||= Hash.new do |hash, key|
    hash[key] = key.delete_suffix('.rb').gsub("#{Dir.pwd}/", '').tr('/', '.')
  end
  @classname_attribute_value_cache[file]
end

def file_finished(file, offenses)
  @inspected_file_count += 1
  # TODO: Returns all cops with the same behavior as
  # the original rubocop-junit-formatter.
  # https://github.com/mikian/rubocop-junit-formatter/blob/v0.1.4/lib/rubocop/formatter/junit_formatter.rb#L9
  #
  # In the future, it would be preferable to return only enabled cops.
  Cop::Registry.all.each do |cop|
    target_offenses = offenses_for_cop(offenses, cop)
    @offense_count += target_offenses.count
    next unless relevant_for_output?(options, target_offenses)
    add_testcase_element_to_testsuite_element(file, target_offenses, cop)
  end
end

def finished(_inspected_files)
  @testsuite.add_attributes('tests' => @inspected_file_count, 'failures' => @offense_count)
  @document.write(output, 2)
end

def initialize(output, options = {})
  super
  @document = REXML::Document.new.tap { |document| document << REXML::XMLDecl.new }
  testsuites = REXML::Element.new('testsuites', @document)
  testsuite = REXML::Element.new('testsuite', testsuites)
  @testsuite = testsuite.tap { |element| element.add_attributes('name' => 'rubocop') }
  reset_count
end

def offenses_for_cop(all_offenses, cop)
  all_offenses.select { |offense| offense.cop_name == cop.cop_name }
end

def relevant_for_output?(options, target_offenses)
  !options[:display_only_failed] || target_offenses.any?
end

def reset_count
  @inspected_file_count = 0
  @offense_count = 0
end