require "optparse"

module Agig::OptParser
  def self.parse!(argv)
    opts = {
      port: 16705,
      host: "localhost",
      interval: 30,
      log: nil,
      debug: false,
      foreground: false,
    }

    OptionParser.new do |parser|
      parser.instance_eval do
        self.banner  = "Usage: #{$0} [opts]"
        separator ""

        separator "Options:"
        on("-p", "--port [PORT=#{opts[:port]}]", "port number to listen") do |port|
          opts[:port] = port
        end

        on("-h", "--host [HOST=#{opts[:host]}]", "host name or IP address to listen") do |host|
          opts[:host] = host
        end

        on("-i", "--interval [INTERVAL=#{opts[:interval]}]", "set a retrieving interval") do |interval|
          opts[:interval] = interval
        end

        on("-l", "--log LOG", "log file") do |log|
          opts[:log] = log
        end

        on("-d", "--debug", "Enable debug mode") do |debug|
          opts[:log]   = $stdout
          opts[:debug] = true
        end

        on("-f", "--foreground", "run foreground") do |foreground|
          opts[:log]        = $stdout
          opts[:foreground] = true
        end

        parse!(argv)
      end
    end

    self.cast opts
  end

  def self.cast(opts)
    opts.inject({}) {|r, i|
      key, value = i[0], i[1]
      r.update key => case value
                      when nil                      then false
                      when /\A\d+\z/                then value.to_i
                      when /\A(?:\d+\.\d*|\.\d+)\z/ then value.to_f
                      else                               value
                      end
    }
  end
end