# frozen_string_literal: true

# The Datagram class parses and inspects a StatsD datagrams
#
# @note This class is part of the new Client implementation that is intended
#   to become the new default in the next major release of this library.
class StatsD::Instrument::DogStatsDDatagram < StatsD::Instrument::Datagram
  def name
    @name ||= case type
    when :_e then parsed_datagram[:name].gsub('\n', "\n")
    else super
    end
  end

  def value
    @value ||= case type
    when :_sc then Integer(parsed_datagram[:value])
    when :_e then parsed_datagram[:value].gsub('\n', "\n")
    else super
    end
  end

  def hostname
    parsed_datagram[:hostname]
  end

  def timestamp
    Time.at(Integer(parsed_datagram[:timestamp])).utc
  end

  def aggregation_key
    parsed_datagram[:aggregation_key]
  end

  def source_type_name
    parsed_datagram[:source_type_name]
  end

  def priority
    parsed_datagram[:priority]
  end

  def alert_type
    parsed_datagram[:alert_type]
  end

  def message
    parsed_datagram[:message]
  end

  protected

  def parsed_datagram
    @parsed ||= if (match_info = PARSER.match(@source))
      match_info
    else
      raise ArgumentError, "Invalid DogStatsD datagram: #{@source}"
    end
  end

  SERVICE_CHECK_PARSER = %r{
    \A
    (?<type>_sc)\|(?<name>[^\|]+)\|(?<value>\d+)
    (?:\|h:(?<hostname>[^\|]+))?
    (?:\|d:(?<timestamp>\d+))?
    (?:\|\#(?<tags>(?:[^\|,]+(?:,[^\|,]+)*)))?
    (?:\|m:(?<message>[^\|]+))?
    \n? # In some implementations, the datagram may include a trailing newline.
    \z
  }x

  # |k:my-key|p:low|s:source|t:success|
  EVENT_PARSER = %r{
    \A
    (?<type>_e)\{\d+\,\d+\}:(?<name>[^\|]+)\|(?<value>[^\|]+)
    (?:\|h:(?<hostname>[^\|]+))?
    (?:\|d:(?<timestamp>\d+))?
    (?:\|k:(?<aggregation_key>[^\|]+))?
    (?:\|p:(?<priority>[^\|]+))?
    (?:\|s:(?<source_type_name>[^\|]+))?
    (?:\|t:(?<alert_type>[^\|]+))?
    (?:\|\#(?<tags>(?:[^\|,]+(?:,[^\|,]+)*)))?
    \n? # In some implementations, the datagram may include a trailing newline.
    \z
  }x

  PARSER = Regexp.union(StatsD::Instrument::Datagram::PARSER, SERVICE_CHECK_PARSER, EVENT_PARSER)
end