require "getopt/long"

module Hermes
  def self.extended(klass)
    klass.class_eval <<-RUBY, "class_cli.rb", 6
    
      def self.method_added(meth)
        return if !public_instance_methods.include?(meth.to_s) || !@@usage
        @@descriptions                         = defined?(@@descriptions) ? @@descriptions : []
        @@usages                               = defined?(@@usages) ? @@usages : []
        @@opts                                 = defined?(@@opts) ? @@opts : []
        @@descriptions                        << [meth.to_s, @@desc]
        @@usages                              << [meth.to_s, @@usage]
        if defined?(@@method_options) && @@method_options
          @@opts                                << [meth.to_s, @@method_options]
        end
        @@usage, @@desc, @@method_options      = nil
      end

      def self.desc(usage, description)
        @@usage, @@desc = usage, description
      end
      
      def self.method_options(opts)
        @@method_options = opts
      end

      def self.start
        meth = ARGV.shift
        params = ARGV.inject([]) do |accum, arg|
          accum << ARGV.delete(arg) unless arg =~ /^\-/
          accum
        end
        if @@opts.assoc(meth)
          opts = @@opts.assoc(meth).last.map {|opt, val| [opt, val == true ? Getopt::BOOLEAN : Getopt.const_get(val)].flatten}
          options = Getopt::Long.getopts(*opts)
          params << options
        end
        new(meth, params)
      end

      def initialize(op, params)
        send(op.to_sym, *params) if public_methods.include?(op)
      end
      
      private
      def format_opts(opts)
        return "" unless opts
        opts.map do |opt, val|
          if val == true || val == "BOOLEAN"
            opt
          elsif val == "REQUIRED"
            opt + "=" + opt.gsub(/\-/, "").upcase
          elsif val == "OPTIONAL"
            "[" + opt + "=" + opt.gsub(/\-/, "").upcase + "]"
          end
        end.join(" ")
      end
      
      public
      desc "help", "show this screen"
      def help
        puts "Options"
        puts "-------"
        max_usage = @@usages.max {|x,y| x.last.to_s.size <=> y.last.to_s.size}.last.size
        max_opts  = @@opts.empty? ? 0 : format_opts(@@opts.max {|x,y| x.last.to_s.size <=> y.last.to_s.size}.last).size 
        max_desc  = @@descriptions.max {|x,y| x.last.to_s.size <=> y.last.to_s.size}.last.size
        @@usages.each do |meth, usage|
          format = "%-" + (max_usage + max_opts + 4).to_s + "s"
          print format % (@@usages.assoc(meth)[1] + (@@opts.assoc(meth) ? " " + format_opts(@@opts.assoc(meth)[1]) : ""))
          # print format % (@@usages.assoc(meth)[1] + @@opts.assoc(meth) ? format_opts(@@opts.assoc(meth)[1]) : ""))
          puts  @@descriptions.assoc(meth)[1]      
        end
      end      
    RUBY
  end
end