class CopsDocumentationGenerator

def call
  YARD::Registry.load!
  departments.each { |department| print_cops_of_department(department) }
  print_table_of_contents
ensure
  RuboCop::ConfigLoader.default_configuration = nil
end

def check_examples_to_have_the_default_enforced_style!(examples_object, cop)
  return if examples_object.none?
  examples_describing_enforced_style = examples_object.map(&:name).grep(/EnforcedStyle:/)
  return if examples_describing_enforced_style.none?
  if examples_describing_enforced_style.index { |name| name.match?('default') }.nonzero?
    raise "Put the example with the default EnforcedStyle on top for #{cop.cop_name}"
  end
  return if examples_describing_enforced_style.any? { |name| name.match?('default') }
  raise "Specify the default EnforcedStyle for #{cop.cop_name}"
end

def code_example(ruby_code)
  content = +"[source,ruby]\n----\n"
  content << ruby_code.text.gsub('@good', '# good').gsub('@bad', '# bad').strip
  content << "\n----\n"
  content
end

def configurable_values(pars, name)
  case name
  when /^Enforced/
    supported_style_name = RuboCop::Cop::Util.to_supported_styles(name)
    format_table_value(pars[supported_style_name])
  when 'IndentationWidth'
    'Integer'
  when 'Database'
    format_table_value(pars['SupportedDatabases'])
  else
    case pars[name]
    when String
      'String'
    when Integer
      'Integer'
    when Float
      'Float'
    when true, false
      'Boolean'
    when Array
      'Array'
    else
      ''
    end
  end
end

def configuration_name(department, name)
  return name unless name == 'AllowMultilineFinalElement'
  filename = "#{department_to_basename(department)}.adoc"
  "xref:#{filename}#allowmultilinefinalelement[AllowMultilineFinalElement]"
end

def configurations(department, pars)
  return '' if pars.empty?
  header = ['Name', 'Default value', 'Configurable values']
  configs = pars
            .each_key
            .reject { |key| key.start_with?('Supported') }
            .reject { |key| key.start_with?('AllowMultipleStyles') }
  content = configs.map do |name|
    configurable = configurable_values(pars, name)
    default = format_table_value(pars[name])
    [configuration_name(department, name), default, configurable]
  end
  h3('Configurable attributes') + to_table(header, content)
end

def cop_code(cop)
  YARD::Registry.all(:class).detect do |code_object|
    next unless RuboCop::Cop::Badge.for(code_object.to_s) == cop.badge
    yield code_object
  end
end

def cop_status(status)
  return 'Disabled' unless status
  status == 'pending' ? 'Pending' : 'Enabled'
end

def cops_body(cop, description, examples_objects, safety_objects, see_objects, pars) # rubocop:disable Metrics/AbcSize, Metrics/ParameterLists
  check_examples_to_have_the_default_enforced_style!(examples_objects, cop)
  content = h2(cop.cop_name)
  content << required_ruby_version(cop)
  content << properties(cop)
  content << "#{description}\n"
  content << safety_object(safety_objects) if safety_objects.any? { |s| !s.text.blank? }
  content << examples(examples_objects) if examples_objects.any?
  content << configurations(cop.department, pars)
  content << references(cop, see_objects)
  content
end

def cops_of_department(department)
  cops.with_department(department).sort!
end

def examples(examples_object)
  examples_object.each_with_object(h3('Examples').dup) do |example, content|
    content << "\n" unless content.end_with?("\n\n")
    content << h4(example.name) unless example.name == ''
    content << code_example(example)
  end
end

def footer_for_department(department)
  return '' unless department == :Layout
  filename = "#{department_to_basename(department)}_footer.adoc"
  file = "#{Dir.pwd}/docs/modules/ROOT/partials/#{filename}"
  return '' unless File.exist?(file)
  "\ninclude::../partials/#{filename}[]\n"
end

def format_table_value(val)
  value =
    case val
    when Array
      if val.empty?
        '`[]`'
      else
        val.map { |config| format_table_value(config) }.join(', ')
      end
    else
      wrap_backtick(val.nil? ? '<none>' : val)
    end
  value.gsub("#{Dir.pwd}/", '').rstrip
end

def h2(title)
  content = +"\n"
  content << "== #{title}\n"
  content << "\n"
  content
end

def h3(title)
  content = +"\n"
  content << "=== #{title}\n"
  content << "\n"
  content
end

def h4(title)
  content = +"==== #{title}\n"
  content << "\n"
  content
end

def initialize(departments: [])
  @departments = departments.map(&:to_sym).sort!
  @cops = RuboCop::Cop::Registry.global
  @config = RuboCop::ConfigLoader.default_configuration
  @docs_path = "#{Dir.pwd}/docs/modules/ROOT/pages/"
  FileUtils.mkdir_p(@docs_path)
end

def print_cop_with_doc(cop) # rubocop:todo Metrics/AbcSize, Metrics/MethodLength
  cop_config = config.for_cop(cop)
  non_display_keys = %w[
    Description Enabled StyleGuide Reference Safe SafeAutoCorrect VersionAdded
    VersionChanged
  ]
  pars = cop_config.reject { |k| non_display_keys.include? k }
  description = 'No documentation'
  examples_object = safety_object = see_object = []
  cop_code(cop) do |code_object|
    description = code_object.docstring unless code_object.docstring.blank?
    examples_object = code_object.tags('example')
    safety_object = code_object.tags('safety')
    see_object = code_object.tags('see')
  end
  cops_body(cop, description, examples_object, safety_object, see_object, pars)
end

def print_cops_of_department(department)
  selected_cops = cops_of_department(department)
  content = +"= #{department}\n"
  selected_cops.each { |cop| content << print_cop_with_doc(cop) }
  content << footer_for_department(department)
  file_name = "#{docs_path}/#{department_to_basename(department)}.adoc"
  File.open(file_name, 'w') do |file|
    puts "* generated #{file_name}"
    file.write("#{content.strip}\n")
  end
end

def print_table_of_contents
  path = "#{docs_path}/cops.adoc"
  File.write(path, table_contents) and return unless File.exist?(path)
  original = File.read(path)
  content = +"// START_COP_LIST\n\n"
  content << table_contents
  content << "\n// END_COP_LIST"
  content = original.sub(%r{// START_COP_LIST.+// END_COP_LIST}m, content)
  File.write(path, content)
end

def properties(cop)
  header = [
    'Enabled by default', 'Safe', 'Supports autocorrection', 'Version Added',
    'Version Changed'
  ]
  autocorrect = if cop.support_autocorrect?
                  "Yes#{' (Unsafe)' unless cop.new(config).safe_autocorrect?}"
                else
                  'No'
                end
  cop_config = config.for_cop(cop)
  content = [[
    cop_status(cop_config.fetch('Enabled')),
    cop_config.fetch('Safe', true) ? 'Yes' : 'No',
    autocorrect,
    cop_config.fetch('VersionAdded', '-'),
    cop_config.fetch('VersionChanged', '-')
  ]]
  "#{to_table(header, content)}\n"
end

def references(cop, see_objects) # rubocop:disable Metrics/AbcSize
  cop_config = config.for_cop(cop)
  urls = RuboCop::Cop::MessageAnnotator.new(config, cop.name, cop_config, {}).urls
  return '' if urls.empty? && see_objects.empty?
  content = h3('References')
  content << urls.map { |url| "* #{url}" }.join("\n")
  content << "\n" unless urls.empty?
  content << see_objects.map { |see| "* #{see.name}" }.join("\n")
  content << "\n" unless see_objects.empty?
  content
end

def required_ruby_version(cop)
  return '' unless cop.respond_to?(:required_minimum_ruby_version)
  "NOTE: Required Ruby version: #{cop.required_minimum_ruby_version}\n\n"
end

def safety_object(safety_object_objects)
  safety_object_objects.each_with_object(h3('Safety').dup) do |safety_object, content|
    next if safety_object.text.blank?
    content << "\n" unless content.end_with?("\n\n")
    content << safety_object.text
    content << "\n"
  end
end

def table_contents
  departments.map { |department| table_of_content_for_department(department) }.join("\n")
end

def table_of_content_for_department(department)
  type_title = department[0].upcase + department[1..]
  filename = "#{department_to_basename(department)}.adoc"
  content = +"=== Department xref:#{filename}[#{type_title}]\n\n"
  cops_of_department(department).each do |cop|
    anchor = cop.cop_name.sub('/', '').downcase
    content << "* xref:#{filename}##{anchor}[#{cop.cop_name}]\n"
  end
  content
end

def to_table(header, content)
  table = ['|===', "| #{header.join(' | ')}\n\n"].join("\n")
  marked_contents = content.map do |plain_content|
    # Escape `|` with backslash to prevent the regexp `|` is not used as a table separator.
    plain_content.map { |c| "| #{c.gsub(/\|/, '\|')}" }.join("\n")
  end
  table << marked_contents.join("\n\n")
  table << "\n|===\n"
end

def wrap_backtick(value)
  if value.is_a?(String)
    # Use `+` to prevent text like `**/*.gemspec`, `spec/**/*` from being bold.
    value.include?('*') ? "`+#{value}+`" : "`#{value}`"
  else
    "`#{value}`"
  end
end