# frozen_string_literal: true

# Copyright (C) 2004-2006 Laurent Sansonetti
# Copyright (C) 2008 Joseph Method
# Copyright (C) 2016 Matijs van Zuijlen
#
# Alexandria is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version.
#
# Alexandria is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public
# License along with Alexandria; see the file COPYING.  If not,
# write to the Free Software Foundation, Inc., 51 Franklin Street,
# Fifth Floor, Boston, MA 02110-1301 USA.

module Alexandria
  module UI
    BOOKS_TARGET_TABLE = [Gtk::TargetEntry.new("ALEXANDRIA_BOOKS", :same_app, 0)].freeze

    module DragAndDropable
      BADGE_MARKUP = '<span weight="heavy" foreground="white">%d</span>'

      def setup_view_source_dnd(view)
        # better be Loggable!
        log.info { format("setup_view_source_dnd for %s", view) }
        view.signal_connect_after("drag-begin") do |_widget, drag_context|
          n_books = @parent.selected_books.length
          if n_books > 1
            # Render generic book icon.
            pixmap, mask = Icons::BOOK_ICON.render_pixmap_and_mask(255)

            # Create number badge.
            context = Gdk::Pango.context
            layout = Pango::Layout.new(context)
            layout.markup = BADGE_MARKUP % n_books
            width, height = layout.pixel_size
            x = Icons::BOOK_ICON.width - width - 11
            y = Icons::BOOK_ICON.height - height - 11

            # Draw a red ellipse where the badge number should be.
            red_gc = Gdk::GC.new(pixmap)
            red_gc.rgb_fg_color = Gdk::Color.parse("red")
            red_gc.rgb_bg_color = Gdk::Color.parse("red")
            pixmap.draw_arc(red_gc,
                            true,
                            x - 5, y - 2,
                            width + 9, height + 4,
                            0, 360 * 64)

            # Draw the number badge.
            pixmap.draw_layout(Gdk::GC.new(pixmap), x, y, layout)

            # And set the drag icon.
            Gtk::Drag.set_icon(drag_context,
                               pixmap.colormap,
                               pixmap,
                               mask,
                               10,
                               10)
          end
        end

        view.signal_connect("drag-data-get") do |_, _, selection_data, _, _|
          idents = @parent.selected_books.map(&:ident)
          unless idents.empty?
            selection_data.set(Gdk::Selection::TYPE_STRING,
                               idents.join(","))
          end
        end

        view.enable_model_drag_source(:button1_mask,
                                      Alexandria::UI::BOOKS_TARGET_TABLE,
                                      :move)
      end
    end
  end
end