class Object
  # FIXME: move this, mixin, don't extend Object
  def deep_clone
    case self
    when Fixnum,Bignum,Float,NilClass,FalseClass,TrueClass,Symbol
      klone = self
    when Hash
      klone = self.clone
      self.each{|k,v| klone[k] = v.deep_clone}
    when Array
      klone = self.clone
      klone.clear
      self.each{|v| klone << v.deep_clone}
    else
      klone = self.clone
    end
    klone.instance_variables.each {|v|
      klone.instance_variable_set(v,
      klone.instance_variable_get(v).deep_clone)
    }
    klone
  end

  def send_unless method, *args, &block
    ( block_given? ? yield : self ) or  send method, *args
  end

  def send_if     method, *args, &block
    ( block_given? ? yield : self ) and send method, *args
  end
  
  def to_name
    Card::Name.new self
  end
end



class Module
  RUBY_VERSION_18 = !!(RUBY_VERSION =~ /^1\.8/)
  
  def const_get_if_defined const
    args = RUBY_VERSION_18 ? [ const ] : [ const, false ]
    if const_defined? *args
      const_get *args
    end
  end
  
  def const_get_or_set const
    const_get_if_defined const or const_set const, yield
  end
end



class Hash
  # FIXME: this is too ugly and narrow for a core extension.
  class << self
    def new_from_semicolon_attr_list(attr_string)
      return {} if attr_string.blank?
      attr_string.strip.split(';').inject({}) do |result, pair|
        value, key = pair.split(':').reverse
        key ||= 'view'
        key.strip!; value.strip!
        result[key.to_sym] = value
        result
      end
    end
  end

end


class Kaminari::Helpers::Tag
  def page_url_for page
    p = params_for(page)
    p.delete :controller
    p.delete :action
    card = Card[p.delete('id')]
    card.format.path  p
  end
  
  private
  
  def params_for(page)
    page_params = Rack::Utils.parse_nested_query("#{@param_name}=#{page}")
    page_params = @params.with_indifferent_access.deep_merge(page_params)
    
    if Kaminari.config.respond_to?(:params_on_first_page) && !Kaminari.config.params_on_first_page && page <= 1
      # This converts a hash:
      #   from: {other: "params", page: 1}
      #     to: {other: "params", page: nil}
      #   (when @param_name == "page")
      #
      #   from: {other: "params", user: {name: "yuki", page: 1}}
      #     to: {other: "params", user: {name: "yuki", page: nil}}
      #   (when @param_name == "user[page]")
      @param_name.to_s.scan(/\w+/)[0..-2].inject(page_params){|h, k| h[k] }[$&] = nil
    end
    
    page_params
  end
end