module Redcar
  class TreeViewSWT
    attr_reader :viewer, :model

    extend Forwardable

    def self.storage
      @storage ||= begin
         storage = Plugin::Storage.new('tree_view_swt_plugin')
         storage.set_default('refresh_trees_on_refocus', true)
         storage
      end
    end

    def initialize(composite, model)
      @composite, @model = composite, model
      color = ApplicationSWT.tree_background.swt_colors.first
      font_data = @composite.font.font_data.first
      font = Swt::Graphics::Font.new(
        ApplicationSWT.display,
        font_data.name,
        Redcar::EditView.font_size - 1,
        Swt::SWT::NORMAL)
      @composite.background = color
      tree_style = Swt::SWT::MULTI | Swt::SWT::H_SCROLL | Swt::SWT::V_SCROLL
      @viewer = JFace::Viewers::TreeViewer.new(@composite, tree_style)
      grid_data = Swt::Layout::GridData.new
      grid_data.grabExcessHorizontalSpace = true
      grid_data.horizontalAlignment = Swt::Layout::GridData::FILL
      grid_data.grabExcessVerticalSpace = true
      grid_data.verticalAlignment = Swt::Layout::GridData::FILL
      @viewer.get_tree.set_layout_data(grid_data)
      @composite.layout
      JFace::Viewers::ColumnViewerToolTipSupport.enableFor(@viewer)
      @viewer.set_content_provider(TreeMirrorContentProvider.new(self))
      @viewer.tree.font = font
      @viewer.tree.background = color
      #@viewer.getTree.setLinesVisible(true)
	    #@viewer.getTree.setHeaderVisible(true)
      @viewer.set_label_provider(TreeMirrorLabelProvider.new(self))
      @viewer.set_input(@model.tree_mirror)

      if @model.tree_controller
        @viewer.add_tree_listener(@viewer.getControl, TreeListener.new)
        @viewer.add_double_click_listener(DoubleClickListener.new)
        @viewer.add_open_listener(OpenListener.new(@model))
        @viewer.add_selection_changed_listener(SelectionChangedListener.new(@model, @viewer))
        control.add_mouse_listener(MouseListener.new(self))
      end

      register_dnd if @model.tree_mirror.drag_and_drop?

      @model.add_listener(:refresh) do
        begin
          @model.tree_mirror.refresh_operation(@model) do
            @viewer.refresh unless @viewer.getTree.isDisposed
          end
        rescue => e
          handle_mirror_error(e)
        end
      end

      @editor = Swt::Custom::TreeEditor.new(control)

      @editor.horizontalAlignment = Swt::SWT::LEFT
      @editor.grabHorizontal = true

      @model.add_listener(:edit_element, &method(:edit_element))
      @model.add_listener(:expand_element, &method(:expand_element))
      @model.add_listener(:select_element, &method(:select_element))
      @model.add_listener(:focus, &method(:focus))
    end

    def tree_mirror
      @model.tree_mirror
    end

    def_delegators :control, :layout_data, :layout_data=, :visible, :visible=

    class DragSourceListener
      attr_reader :tree, :dragged_elements

      def initialize(tree_view_swt, tree)
        @tree_view_swt = tree_view_swt
        @tree = tree
      end

      def drag_start(event)
        selection = tree.get_selection
        if selection.length > 0
          event.doit = true
          @dragged_elements = selection.map do |item|
            @tree_view_swt.item_to_element(item)
          end
          Redcar.safely do
            @tree_view_swt.drag_controller.drag_start(@dragged_elements)
          end
        else
          event.doit = false
        end
      end

      def drag_set_data(event)
        case tree_mirror.data_type
        when :file
          Redcar.safely do
            @data = tree_mirror.to_data(dragged_elements).to_java(:string)
          end
          event.data = @data
        when :text
          Redcar.safely do
            @data = tree_mirror.to_data(dragged_elements)
          end
          event.data = @data
        else
          raise "unknown tree data_type #{tree.tree_mirror.data_type}"
        end
      end

      def drag_finished(*_); end

      def tree_mirror
        @tree_view_swt.model.tree_mirror
      end
    end

    class DropAdapter < JFace::Viewers::ViewerDropAdapter
      def initialize(tree_view_swt, drag_source_listener, viewer)
        @tree_view_swt = tree_view_swt
        @drag_source_listener = drag_source_listener
        super(viewer)
      end

      def validateDrop(target, operation, transfer_data_type)
        pos = location_to_position(get_current_location)
        Redcar.safely do
          @tree_view_swt.drag_controller.can_drop?(@drag_source_listener.dragged_elements, target, pos)
        end
      end

      def performDrop(data)
        elements = data.to_a.map {|datum| @tree_view_swt.model.tree_mirror.from_data(datum) }
        pos = location_to_position(get_current_location)
        # Map the single :text element back to it's proper state
        elements = elements[0] if @tree_view_swt.model.tree_mirror.data_type == :text
        Redcar.safely do
          @tree_view_swt.drag_controller.do_drop(elements, get_current_target, pos)
        end
        true
      end

      private

      def location_to_position(location)
        if Redcar.safely { @tree_view_swt.drag_controller.reorderable? }
          {1 => :before, 2 => :after, 3 => :onto}[location]
        else
          :onto
        end
      end
    end

    def register_dnd
      case Redcar.safely { @model.tree_mirror.data_type }
      when :file
        types = [Swt::DND::FileTransfer.getInstance()].to_java(:"org.eclipse.swt.dnd.FileTransfer")
      when :text
        types = [Swt::DND::TextTransfer.getInstance()].to_java(:"org.eclipse.swt.dnd.TextTransfer")
      else
        raise "unknown tree data_type #{Redcar.safely { tree.tree_mirror.data_type }}"
      end
      operations = Swt::DND::DND::DROP_MOVE | Swt::DND::DND::DROP_COPY

      source_listener = DragSourceListener.new(self, @viewer.get_tree)
      drop_adapter = DropAdapter.new(self, source_listener, @viewer)
      drop_adapter.set_feedback_enabled(drag_controller.reorderable?)

      @viewer.add_drag_support(operations, types, source_listener)
      @viewer.add_drop_support(operations, types, drop_adapter)
    end

    def drag_controller
      @model.tree_controller.drag_controller(@model)
    end

    def edit_element(element, select_from, select_to)
      item = element_to_item(element)
      unless item
        puts "ERROR: when trying to edit, no visible item for #{element.inspect}"
        return
      end

      text = Swt::Widgets::Text.new(control, Swt::SWT::NONE)
      text.set_text(item.get_text)
      colour = ApplicationSWT.display.get_system_color(Swt::SWT::COLOR_GRAY)
      text.set_background(colour)

      @editor.set_editor(text, item)
      text.set_selection(select_from || 0, select_to || text.get_text.length)
      listener = EditorListener.new(self, element, text)
      text.add_listener(Swt::SWT::FocusOut, listener)
      text.add_listener(Swt::SWT::Traverse, listener)

      text.set_focus
    end

    def edited_element(element, text)
      if @model.tree_controller and @model.tree_controller.respond_to?(:edited)
        Redcar.safely("edit element") do
          @model.tree_controller.edited(@model, element, text)
        end
      end
    end

    def expand_element(element)
      if item = element_to_item(element)
        @viewer.expandToLevel(element, 1)
      end
    end

    def focus
      @viewer.get_tree.set_focus
    end

    def select_element(element)
      if item = element_to_item(element)
        @viewer.get_tree.set_selection(item)
      end
    end

    def element_to_item(element)
      @viewer.test_find_item(element)
    end

    def item_to_element(item)
      @viewer.getViewerRowFromItem(item).get_element
    end

    def selection
      @viewer.get_tree.get_selection.map {|i| item_to_element(i) }
    end

    def visible_nodes
      items = @viewer.get_tree.get_items
      all_items = items.map {|item| [item, visible_children_of(item)] }.flatten
      all_items.map {|item| item_to_element(item) }
    end

    def visible_children_of(item)
      if item.get_expanded
        items = item.get_items
        items.map {|item| [item, visible_children_of(item) ]}.flatten
      else
        []
      end
    end

    class EditorListener
      def initialize(tree_view_swt, element, text_widget)
        @tree_view_swt = tree_view_swt
        @element = element
        @text = text_widget
      end

      def handle_event(e)
        case e.type
        when Swt::SWT::FocusOut
          new_text = @text.get_text
          @text.dispose
          @tree_view_swt.edited_element(@element, new_text)
        when Swt::SWT::Traverse
          case e.detail
          when Swt::SWT::TRAVERSE_RETURN
            new_text = @text.get_text
            @text.dispose
            e.doit = false
            @tree_view_swt.edited_element(@element, new_text)
          when Swt::SWT::TRAVERSE_ESCAPE
            @text.dispose
            e.doit = false
          end
        end
      end
    end

    def control
      @viewer.get_control
    end

    def close
      @viewer.getControl.dispose
    end
    alias :dispose :close

    def right_click(mouse_event)
      if @model.tree_controller
        point = Swt::Graphics::Point.new(mouse_event.x, mouse_event.y)
        item = @viewer.get_item_at(point)
        element = item ? @viewer.getViewerRowFromItem(item).get_element : nil
        if @model.tree_controller.respond_to?(:right_click)
          Redcar.safely("right click on tree") do
            @model.tree_controller.right_click(@model, element)
          end
        end
      end
    end

    def handle_mirror_error(e)
      if @model.tree_controller.respond_to?(:handle_error)
        begin
          @model.tree_controller.handle_error(@model, e)
        rescue => e
          puts "error in error hander: #{e.class} #{e.message}"
          puts e.backtrace
        end
      else
        puts e.class
        puts e.message
        puts e.backtrace
        Application::Dialog.message_box(e.message, :type => :error)
      end
    end

    class TreeListener
      def tree_collapsed(e)
      end

      def tree_expanded(e)
      end
    end

    class SelectionListener
      def widget_default_selected(e)
      end

      def widget_selected(e)
      end
    end

    class MouseListener
      def initialize(tree_view_swt)
        @tree_view_swt = tree_view_swt
      end

      def mouse_double_click(_); end
      def mouse_up(_)
      end

      def mouse_down(e)
        if e.button == 3
          @tree_view_swt.right_click(e)
        end
      end
    end

    class SelectionChangedListener
      def initialize(tree_model, viewer)
        @tree_model = tree_model
        @viewer = viewer
      end

      def selection_changed(e)
        Redcar.safely do
          element = e.getSelection.toArray.to_a.first
          if @tree_model.tree_controller.selected(@tree_model, element)
            @viewer.expandToLevel(element, 1)
          end
        end
      end
    end

    class DoubleClickListener
      def double_click(e)

        double_clicked_element = e.get_viewer.get_selection.get_first_element

        #do nothing for leaves
        return if double_clicked_element.leaf?

        viewer = e.get_viewer
        node_is_expanded = viewer.getExpandedState(double_clicked_element)

        if node_is_expanded
          viewer.collapseToLevel(double_clicked_element, 1)
        else
          viewer.expandToLevel(double_clicked_element, 1)
        end
      rescue
      end
    end

    class OpenListener
      def initialize(tree_model)
        @tree_model = tree_model
      end

      def open(e)
        Redcar.safely("tree row activation") do
          @tree_model.tree_controller.activated(@tree_model, e.getSelection.toArray.to_a.first)
        end
      end
    end

    class TreeMirrorContentProvider
      include JFace::Viewers::ITreeContentProvider

      def initialize(tree_view_swt)
        @tree_view_swt = tree_view_swt
      end

      def input_changed(viewer, _, tree_mirror)
        @viewer, @tree_mirror = viewer, tree_mirror
      end

      def get_elements(tree_mirror)
        tree_mirror.top.to_java
      rescue => e
        puts e.message
        puts e.backtrace
        @tree_view_swt.handle_mirror_error(e)
      end

      def has_children(tree_node)
        if tree_node.respond_to?(:children?)
          tree_node.children?
        else
          children = tree_node.children
          children.any? if children
        end
      rescue => e
        puts e.message
        puts e.backtrace
        @tree_view_swt.handle_mirror_error(e)
      end

      def get_children(tree_node)
        tree_node.children.to_java
      rescue => e
        puts e.message
        puts e.backtrace
        @tree_view_swt.handle_mirror_error(e)
      end

      def get_parent(tree_node)
        # not sure why this is necessary
      end

      def dispose
      end
    end

    class TreeMirrorLabelProvider
      include JFace::Viewers::ILabelProvider

      def initialize(tree_view_swt)
        @tree_view_swt = tree_view_swt
      end

      def add_listener(*_)
      end

      def remove_listener(*_)
      end

      def get_text(tree_node)
        tree_node.text
      end

      def get_image(tree_node)
        ApplicationSWT::Icon.swt_image(tree_node.icon)
      end

      def dispose
      end

      #def getToolTipShift(*_)
      #  Swt::Graphics::Point.new(5, 5)
      #end
      #
      #def getToolTipText(tree_node)
      #  p [:getToolTipText, tree_node]
      #  tree_node.tooltip_text
      #end
      #
      #def getToolTipDisplayDelayTime(*_)
      #  1000
      #end
      #
      #def getToolTipTimeDisplayed(*_)
      #  5000
      #end

    end
  end
end