class Solargraph::Diagnostics::Rubocop

def diagnose source, _api_map
  options, paths = generate_options(source.filename, source.code)
  runner = RuboCop::Runner.new(options, RuboCop::ConfigStore.new)
  result = redirect_stdout{ runner.run(paths) }
  make_array JSON.parse(result)
rescue RuboCop::ValidationError, RuboCop::ConfigNotFoundError => e
  raise DiagnosticsError, "Error in RuboCop configuration: #{e.message}"
rescue JSON::ParserError
  raise DiagnosticsError, 'RuboCop returned invalid data'
end

def make_array resp
  diagnostics = []
  resp['files'].each do |file|
    file['offenses'].each do |off|
      diagnostics.push offense_to_diagnostic(off)
    end
  end
  diagnostics
end

def offense_ending_position off
  if off['location']['start_line'] != off['location']['last_line']
    Position.new(off['location']['start_line'], 0)
  else
    Position.new(
      off['location']['start_line'] - 1, off['location']['last_column']
    )
  end
end

def offense_range off
  Range.new(offense_start_position(off), offense_ending_position(off))
end

def offense_start_position off
  Position.new(off['location']['start_line'] - 1, off['location']['start_column'] - 1)
end

def offense_to_diagnostic off
  {
    range: offense_range(off).to_hash,
    # 1 = Error, 2 = Warning, 3 = Information, 4 = Hint
    severity: SEVERITIES[off['severity']],
    source: off['cop_name'],
    message: off['message'].gsub(/^#{off['cop_name']}\:/, '')
  }
end

def redirect_stdout
  redir = StringIO.new
  $stdout = redir
  yield if block_given?
  $stdout = STDOUT
  redir.string
end