module Rack::Insight
  class CachePanel

    class Stats
      class Query
        attr_reader :method, :time, :hit, :keys

        def initialize(method, time, hit, keys)
          @method = method
          @time = time
          @hit = hit
          @keys = keys
        end

        def display_time
          "%.2fms" % time
        end

        def display_keys
          if keys.size == 1
            keys.first
          else
            keys.join(", ")
          end
        end
      end

      attr_reader :calls, :keys, :queries, :time

      def initialize
        @queries = []
        @misses =
          @calls = 0
        @time = 0.0
        @keys = []
      end

      def record_call(method, time, hit, key)
        if Array === key
          @queries << Query.new(:get_multi, time, hit, key)
        else
          @queries << Query.new(method.to_sym, time, hit, [key])
        end
        @calls += 1
        @time += time
        @keys += keys
      end

      def display_time
        "%.2fms" % time
      end

      def gets
        count_queries(:get)
      end

      def sets
        count_queries(:set)
      end

      def deletes
        count_queries(:delete)
      end

      def get_multis
        count_queries(:get_multi)
      end

      def hits
        @queries.select { |q| [:get, :get_multi].include?(q.method) && q.hit }.size
      end

      def misses
        @queries.select { |q| [:get, :get_multi].include?(q.method) && !q.hit }.size
      end

      def count_queries(method)
        @queries.select { |q| q.method == method }.size
      end

      def queries_to_param
        params = {}
        @queries.each_with_index do |query, index|
          params["keys_#{index}"] = query.keys.first
        end
        params
      end
    end
  end
end