require 'active_support/core_ext'
require 'shell'

class OptBuilder
  
    class_attribute :single_opts
    class_attribute :collection_opts
    self.single_opts = []    
    self.collection_opts = []
    
    def self.inherited(sub)
      sub.single_opts = []    
      sub.collection_opts = []
    end

    def self.map_with_single_opts(&block)
      result = self.single_opts.map do |config|
        yield config
      end
      
      result += self.superclass.map_with_single_opts(&block) if (self.superclass.respond_to? :map_with_single_opts)
      result
    end

    def self.map_with_collection_opts(&block)
      result = self.collection_opts.map do |config|
        yield config
      end
      
      result += self.superclass.map_with_collection_opts(&block) if (self.superclass.respond_to? :map_with_single_opts)
      result        
    end

    
    def self.single(sym,opts={})
      attr_writer sym

      self.single_opts << { 
        :sym => sym, 
        :alias_for => opts[:alias_for] || sym.to_s.dasherize 
      }
      
      self.class_eval do
        define_method sym do
          result = self.send(:instance_variable_get,"@#{sym.to_s}")
          result = opts[:default] if result.nil?
          result
        end
      end
    end  

    def self.collection(sym,opts={})
      attr_writer sym

      self.collection_opts << {
        :sym => sym, 
        :force_restart => opts[:force_restart], 
        :alias_for => opts[:alias_for] || sym.to_s.dasherize 
      }
      
      self.class_eval do
        define_method sym do
          value = self.send(:instance_variable_get,"@#{sym.to_s}") || []
          self.send(:instance_variable_set,"@#{sym.to_s}", value)
          value
        end

      end
    end  

    def value_as_option_value(value)
      return value_array_as_option_value(value) if value.is_a? Array
      Shell.escape value
    end
    
    def value_array_as_option_value(value_array)
      ary = value_array.map do |value|
        value_as_option_value(value)
      end
      
      ary.join " "
    end

    def to_s
      opts = self.class.map_with_single_opts do |config|
        sym = config[:sym]
        "-#{config[:alias_for]}=#{value_as_option_value(send(sym))}" unless send(sym).nil?
      end

      opts += self.class.map_with_collection_opts do |hash|
        sym = hash[:sym];
        restart = hash[:force_restart]
        add_char = ""
        send(sym).map do |value|
          add_char = "+" unless restart
          restart = false if restart
          "-#{hash[:alias_for]}#{add_char}=#{value_as_option_value(value)}" unless send(sym).nil?
        end
      end
      
      opts.flatten.reject{ |item| item.nil? }.join " "
    end

end