require "uri"
begin
  require "statsd"
rescue LoadError
  raise 'Gem dogstatsd-ruby is required for logging metrics. Please add the gem "dogstatsd-ruby" to your Gemfile.'
end

# Example:
#   Sapience.add_appender(:datadog, {url: "udp://localhost:2222"})
#
module Sapience
  module Appender
    class Datadog < Sapience::Subscriber
      # Create Appender
      #
      # Parameters:
      #   level: :trace
      #   url: [String]
      #     Valid URL to post to.
      #     Example:
      #       udp://localhost:8125
      #     Example, send all metrics to a particular namespace:
      #       udp://localhost:8125/namespace
      #     Default: udp://localhost:8125
      #   tags: [String]
      #     Example:
      #       tag1:true
      # rubocop:disable AbcSize, CyclomaticComplexity, PerceivedComplexity

      def initialize(options = {}, &block)
        fail("Options should be a Hash") unless options.is_a?(Hash)
        url   = options.delete(:url) || "udp://localhost:8125"
        @tags = options.delete(:tags)
        @uri  = URI.parse(url)
        fail('Statsd only supports udp. Example: "udp://localhost:8125"') if @uri.scheme != "udp"

        super(options, &block)
      end

      def provider
        @_provider ||= begin
          statsd           = ::Statsd.new(@uri.host, @uri.port, tags: @tags)
          path             = @uri.path.chomp("/")
          statsd.namespace = path.sub("/", "") if path != ""
          statsd
        end
      end

      # Send an error notification to sentry
      def log(log)
        metric = log.metric
        return false unless metric

        if log.duration
          timing(metric, log.duration)
        else
          amount = (log.metric_amount || 1).round
          if amount < 0
            decrement(metric, amount.abs)
          else
            increment(metric, amount)
          end
        end
        true
      end

      def timing(metric, duration)
        provider.timing(metric, duration)
      end

      def increment(metric, amount = 1)
        provider.batch do
          amount.times { provider.increment(metric) }
        end
      end

      def decrement(metric, amount = 1)
        provider.batch do
          amount.times { provider.decrement(metric) }
        end
      end

      def histogram(metric, amount)
        provider.histogram(metric, amount)
      end

      def gauge(metric, amount, hash)
        provider.gauge(metric, amount, hash)
      end

      def count(metric, amount, hash)
        provider.count(metric, amount, hash)
      end

      def batch
        yield provider
      end

      def event(title, text, options = {})
        provider.event(title, text, options)
      end
    end
  end
end