require_relative 'observable_array'
require_relative 'observable_model'
require_relative 'observable'
require_relative 'observer'

module Glimmer
  module SWT
    class TreeItemsBinding
      include Glimmer
      include Observable
      include Observer
      include_package 'org.eclipse.swt'
      include_package 'org.eclipse.swt.widgets'

      def initialize(parent, model_binding, tree_properties)
        @tree = parent
        @model_binding = model_binding
        @tree_properties = [tree_properties].flatten.first.to_h
        call(@model_binding.evaluate_property)
        model = model_binding.base_model
        observe(model, model_binding.property_name_expression)
        @tree.on_widget_disposed do |dispose_event|
          unregister_all_observables
        end
      end
      def call(model_tree_root_node=nil)
        if model_tree_root_node and model_tree_root_node.respond_to?(@tree_properties[:children])
          observe(model_tree_root_node, @tree_properties[:text])
          observe(model_tree_root_node, @tree_properties[:children])
          @model_tree_root_node = model_tree_root_node
        end
        populate_tree(@model_tree_root_node, @tree, @tree_properties)
      end
      def populate_tree(model_tree_root_node, parent, tree_properties)
        parent.widget.removeAll
        populate_tree_node(model_tree_root_node, parent.widget, tree_properties)
      end
      def populate_tree_node(model_tree_node, parent, tree_properties)
        table_item = TreeItem.new(parent, GSWT[:none])
        table_item.setText((model_tree_node && model_tree_node.send(tree_properties[:text])).to_s)
        [model_tree_node && model_tree_node.send(tree_properties[:children])].flatten.to_a.compact.each do |child|
          observe(child, @tree_properties[:text])
          populate_tree_node(child, table_item, tree_properties)
        end
      end

    end
  end
end