require 'optparse'
require 'tailstrom/counter_collection'
require 'tailstrom/table'
require 'thread'

module Tailstrom
  module Command
    class Stat
      SCHEMA = [
        { :name => 'count', :width => 7 },
        { :name => 'min', :width => 15 },
        { :name => 'max', :width => 15 },
        { :name => 'avg', :width => 15 }
      ]

      def initialize(argv)
        @infile = $stdin
        @counters = CounterCollection.new
        @table = Table.new SCHEMA
        parse_option argv
      end

      def run
        Thread.start {
          loop do
            while line = @infile.gets
              line = line.chomp
              parse_line line
            end
            sleep 0.1
          end
        }

        @table.print_header

        loop do
          unless @counters.empty?
            c = @counters[:all]
            @table.print_row c.count, c.min, c.max, c.avg
          end
          @counters.clear
          sleep @options[:interval]
        end
      rescue Interrupt
        exit 0
      end

      def parse_line(line)
        columns = line.split @options[:delimiter]
        value = @options[:field] ? columns[@options[:field]] : line
        value = value =~ /\./ ? value.to_f : value.to_i
        @counters[:all] << value
      end

      def parse_option(argv)
        @options = {
          :delimiter => "\t",
          :interval => 1
        }
        opt = OptionParser.new(argv)
        opt.on('-f [field]', Integer) {|v| @options[:field] = v - 1 }
        opt.on('-d [delimiter]', String) {|v| @options[:delimiter] = v }
        opt.on('-i [interval]', Integer) {|v| @options[:interval] = v }
        opt.parse!
      end
    end
  end
end