module Nitro

# A collection of intelligent url encoding methods.

module EncodeUrl

private

  # Encode controller, action, params into a valid url.
  # Automatically respects nice urls and routing.
  #
  # Handles parameters either as a hash or as an array.
  # Use the array method to pass parameters to 'nice' actions.
  #
  # Pass Controller, action, and (param_name, param_value) 
  # pairs.
  #
  # === Examples
  #
  # encode_url ForaController, :post, :title, 'Hello', :body, 'World'
  # encode_url :post, :title, 'Hello', :body, 'World' # => implies controller == self
  # encode_url :kick, :oid, 4
  # encode_url article # => article.to_href
  # 
  # Alternatively you can pass options with a hash:
  #
  # encode_url :controller => ForaController, :action => :delete, :params => { :title => 'Hello' }
  # encode_url :action => :delete
  #--
  # FIXME: better implementation? optimize this?
  # TODO: move elsewhere.
  #++
  
  def encode_url(*args)
    f = args.first
    
    # A standard url as string, return as is.
    
    if f.is_a? String
      return f
    end
  
    # If the passed param is an object that responds to :to_href
    # returns the url to this object.
    
    if f.respond_to? :to_href
      return args.first.to_href
    end
    
    if f.is_a? Symbol
      # no controller passed, try to use self as controller.
      if self.is_a? Nitro::Controller
        args.unshift(self.class)
      else
        raise 'No controller passed to encode_url'
      end
    end

    # Try to encode using the router.
    
    if url = Context.current.dispatcher.encode_route(*args)
      return url
    end
    
    # No routing rule, manual encoding.
    
    controller = args.shift
    action = args.shift.to_sym
    
    if action == :index
      url = "#{controller.mount_path}"
    else
      mount_path = controller.mount_path
      mount_path = nil if mount_path == '/'    
      url = "#{mount_path}/#{action}"
    end
      
    unless args.empty?
      if controller.respond_to_action_or_template? action
        param_count = controller.instance_method(action).arity
        if param_count != 0
          param_count.times do
            args.shift # name 
            url << "/#{CGI.escape(args.shift.to_s)}"
          end        
        end
      end
      
      unless args.empty?
        url << '?'
        params = []
        (args.size / 2).times do
          params << "#{args.shift}=#{args.shift}" 
        end
        url << params.join(';')
      end
    end
    
    return url  
  end
  alias R encode_url

  # Just like encode_url, but generates an absolute url instead.
  
  def encode_absolute_url(*args)
    return "#{request.host_url}#{encode_url(*args)}"
  end
  alias RA encode_absolute_url
  
end

end