module CopHelper

def _investigate(cop, processed_source)
  team = RuboCop::Cop::Team.new([cop], nil, raise_error: true)
  report = team.investigate(processed_source)
  @last_corrector = report.correctors.first || RuboCop::Cop::Corrector.new(processed_source)
  report.offenses
end

def autocorrect_source(source, file = nil)
  RuboCop::Formatter::DisabledConfigFormatter.config_to_allow_offenses = {}
  RuboCop::Formatter::DisabledConfigFormatter.detected_styles = {}
  cop.instance_variable_get(:@options)[:auto_correct] = true
  processed_source = parse_source(source, file)
  _investigate(cop, processed_source)
  @last_corrector.rewrite
end

def autocorrect_source_file(source)
  Tempfile.open('tmp') { |f| autocorrect_source(source, f) }
end

def inspect_source(source, file = nil)
  RuboCop::Formatter::DisabledConfigFormatter.config_to_allow_offenses = {}
  RuboCop::Formatter::DisabledConfigFormatter.detected_styles = {}
  processed_source = parse_source(source, file)
  unless processed_source.valid_syntax?
    raise 'Error parsing example code: ' \
      "#{processed_source.diagnostics.map(&:render).join("\n")}"
  end
  _investigate(cop, processed_source)
end

def inspect_source_file(source)
  Tempfile.open('tmp') { |f| inspect_source(source, f) }
end

def parse_source(source, file = nil)
  if file.respond_to?(:write)
    file.write(source)
    file.rewind
    file = file.path
  end
  RuboCop::ProcessedSource.new(source, ruby_version, file)
end