class RuboCop::CachedData

def deserialize_offenses(offenses)
  source_buffer = Parser::Source::Buffer.new(@filename)
  source_buffer.source = File.read(@filename, encoding: Encoding::UTF_8)
  offenses.map! do |o|
    location = Parser::Source::Range.new(source_buffer,
                                         o['location']['begin_pos'],
                                         o['location']['end_pos'])
    Cop::Offense.new(o['severity'], location,
                     o['message'],
                     o['cop_name'], o['status'].to_sym)
  end
end

def from_json(text)
  deserialize_offenses(JSON.parse(text))
end

def initialize(filename)
  @filename = filename
end

def message(offense)
  # JSON.dump will fail if the offense message contains text which is not
  # valid UTF-8
  offense.message.scrub
end

def serialize_offense(offense)
  {
    # Calling #to_s here ensures that the serialization works when using
    # other json serializers such as Oj. Some of these gems do not call
    # #to_s implicitly.
    severity: offense.severity.to_s,
    location: {
      begin_pos: offense.location.begin_pos,
      end_pos: offense.location.end_pos
    },
    message:  message(offense),
    cop_name: offense.cop_name,
    status:   offense.status
  }
end

def to_json(offenses)
  JSON.dump(offenses.map { |o| serialize_offense(o) })
end