=begin
ViewType ListPane - a simple interface to use lists - rails-copy

Usage:

  include VTListPane

  gui_vbox do
    vtlp_list :names, 'nm'
    show_button :delete
  end
  gui_vbox do
    show_find :name
    show_str :login
    show_int :uid
  end

This will show a list with all available names. The data_class needs to have the following
methods defined (they're already defined if ":nm" exists in data_class):

  def list_nm
  end
  def find_nm
  end

The following buttons are defined:
 - new - clear the fields
 - save - saves the entry, eventually adding a new field
 - delete - takes away the chosen entry
=end

module VTListPane
  def vtlp_setup(field, method, *args)
    @vtlp_field = field.to_s
    @vtlp_method = method.to_s.sub(/^rev_/, "")
    if args.length > 0 and args[0].class == String
      @vtlp_method_list = args.shift
    else
      @vtlp_method_list = "listp_#{method.to_s}"
    end
    if args.length > 0 and args[0].class == Hash
      args.shift
    else
      {}
    end
  end

  def vtlp_list(field, method, *args)
    @vtlp_use_entity = false
    args_hash = vtlp_setup(field, method, *args)
    show_list_single field, "Entities.#{@data_class.class.to_s}.#{@vtlp_method_list}",
                     args_hash.merge(:callback => true)
    self.class_eval <<-RUBY
      def rpc_list_choice_#{field}( session, data )
        rpc_list_choice_vtlistpanel( session, "#{field}", data )
      end
    RUBY
  end

  def vtlp_list_entity(field, entity, method, *args)
    @vtlp_use_entity = true
    args_hash = vtlp_setup(field, method, *args)
    show_entity field, entity, 'single',
                @vtlp_method,
                args_hash.merge(:callback => true)
  end

  def vtlp_get_entity(d)
    @vtlp_use_entity ? d : @data_class.get_data_instance(d[@vtlp_field][0])
  end

  def vtlp_update_list(session, choice = nil)
    list = @data_class.send(@vtlp_method_list)
    newval = (list + [choice]).compact
    rep = reply(:empty_update, @vtlp_field => newval)

    if @update
      rep += rpc_update(session)
    end
    rep
  end

  def rpc_button_new(session, data)
    reply(:empty, empty_fields) +
        vtlp_update_list(session)
  end

  def rpc_button_delete(session, data)
    dputs(3) { "session, data: #{[session, data.inspect].join(':')}" }
    id = vtlp_get_entity(data)
    dputs(3) { "Got #{id.inspect}" }
    if id
      dputs(2) { "Deleting entry #{id}" }
      id.delete
    end

    vtlp_update_list(session)
  end

  def rpc_button_save(session, data)
    field = vtlp_get_entity(data)
    dputs(3) { "Field is #{field.inspect}, setting data #{data.inspect}" }
    selection = data[@vtlp_field][0]
    if field
      field.data_set_hash(data.to_sym)
    else
      if data[@vtlp_method].to_s.length > 0
        n = @data_class.create(data.to_sym)
        selection = n.id
      else
        dputs(0) { "Didn't have a #{@vtlp_method}" }
      end
    end
    dputs(3) { "vtlp_method is #{@vtlp_method} - selection is #{selection.inspect}" }
    vtlp_update_list(session, selection)
  end

  def empty_fields
    layout_recurse.select { |l|
      !%w(list button entity).index(l.dtype.to_s)
    }.collect { |l| l.name }
  end

  def rpc_list_choice_vtlistpanel(session, name, data)
    #dputs_func
    ret = if @update and @update == :before
            rpc_update(session)
          else
            []
          end
    dputs(3) { "rpc_list_choice with #{name} - #{data.inspect}" }
    if name == @vtlp_field
      dputs(4) { layout_recurse.collect { |l| "#{l.name}::#{l.dtype}" }.join(' - ') }
      dputs(4) { empty_fields.join(' - ') }
      ret = reply(:empty, empty_fields)
      item = if @vtlp_use_entity
               field_value = data[name].get_unique
               data[name]
             else
               field_value = data[name][0]
               dputs(4) { "replying with field_value of #{field_value}" }
               vtlp_get_entity(data)
             end
      dputs(4) { "item is #{item.inspect}" }
      if item
        ret += reply(:update, item.to_hash)
      end
      ret += reply(:update, {@vtlp_field.to_sym => [field_value]})
      session.s_data[@vtlp_field.to_sym] = field_value
    end
    if @update and @update != :before
      ret += rpc_update(session)
    end

    dputs(3) { "reply is #{ret.inspect}" }
    ret
  end
end