require 'uri'

# class that groks the igp command line options and invokes the ping task
class Igp::Shell

  # holds the parsed options
  attr_reader :options
  # holds the URI object representing the ping target
  attr_reader :uri

  # initializes the shell with command line argments:
  #
  # +options+ is expected to be the hash structure as provided by GetOptions.new(..)
  #
  # +args+ is the remaining command line arguments
  #
  def initialize(options,args)
    defaults = {
      :interval => 1
    }
    @options = defaults.merge( (options||{}).each{|k|k} )
    return unless args.first
    resolve_addressing args.first
    normalise_options
  end

  protected

  # decodes the +host+ string to type, host, port and sets the uri
  def resolve_addressing(host)
    @uri = URI.parse(host)
    unless uri.scheme
      @options[:type] = :icmp
      @options[:host] = uri.to_s
      @options[:url] = "#{@options[:type].to_s}://#{@options[:host]}"
      return
    end
    @options[:url] = uri.to_s
    @options[:type] = uri.scheme.to_sym
    @options[:port] = uri.port
    @options[:host] = uri.host
  end

  # sets defaults where required
  def normalise_options
    @options[:interval] = @options[:interval].to_i
    @options[:limit] = @options[:limit].to_i if @options[:limit]
  end

  public

  # runs the ping task
  def run
    case options[:type]
    when :icmp,:http,:https,:tcp,:udp,:ldap,:ldaps
      Igp::Base.new(options).run
    else
      usage
    end
  end

  # defines the valid command line options
  OPTIONS = %w(help verbose interval=i limit=i)

  # prints usage/help information
  def usage
    self.class.usage
  end
  # prints usage/help information
  def self.usage
    $stderr.puts <<-EOS

It goes PING! v#{Igp::VERSION}
===================================

Usage:
  igp [options] uri
  
Options:
  -h | --help    :shows command help
  -i= | --interval=seconds (default: 1 second)
  -l= | --limit=number of tests (default: infinite)

The uri specifies the protocol, hostname and port.
The ICMP protocol is assumed if not specified.
The default well-known port is assumed if not specified.

Examples:

  ICMP ping:
    igp localhost
    igp icmp://localhost

  UDP/TCP ping:
    igp udp://localhost:123
    igp tcp://localhost:843

  HTTP/S ping:
    igp http://localhost:8080
    igp https://localhost:4443

  LDAP/S ping:
    igp ldap://localhost
    igp ldaps://localhost:6636

    EOS
  end
end