# frozen_string_literal: true

module Jaeger
  module Client
    module Samplers
      # Probabilistic sampler
      #
      # Sample a portion of traces using trace_id as the random decision
      class Probabilistic
        def initialize(rate: 0.001)
          if rate < 0.0 || rate > 1.0
            raise "Sampling rate must be between 0.0 and 1.0, got #{rate.inspect}"
          end

          @boundary = TraceId::TRACE_ID_UPPER_BOUND * rate
          @tags = {
            'sampler.type' => 'probabilistic',
            'sampler.param' => rate
          }
        end

        def sample?(trace_id:, **)
          [@boundary >= trace_id, @tags]
        end
      end
    end
  end
end