# Copyright (C) 2004-2006 Laurent Sansonetti
# Copyright (C) 2008 Joseph Method
# Modifications Copyright (C) 2011 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
    MAX_RATING_STARS = 5
    class UIManager < BuilderBase
      attr_accessor :main_app, :actiongroup, :appbar, :prefs, :listview, :iconview, :listview_model,
        :iconview_model, :filtered_model
      attr_reader :model
      include Logging
      include GetText
      GetText.bindtextdomain(Alexandria::TEXTDOMAIN, charset: 'UTF-8')

      module Columns
        COVER_LIST, COVER_ICON, TITLE, TITLE_REDUCED, AUTHORS,
          ISBN, PUBLISHER, PUBLISH_DATE, EDITION, RATING, IDENT,
          NOTES, REDD, OWN, WANT, TAGS, LOANED_TO = (0..17).to_a # duplicated from listview.rb
      end

      # The maximum number of rating stars displayed.
      MAX_RATING_STARS = 5

      def initialize(parent)
        super('main_app__builder.glade',  widget_names)
        @parent = parent

        @library_separator_iter = nil
        @libraries = nil
        @move_mid = nil
        @clicking_on_sidepane = true

        get_preferences
        load_libraries
        setup_window_icons
        setup_callbacks
        create_uimanager
        add_menus_and_popups_from_xml
        setup_menus
        setup_toolbar
        setup_move_actions
        setup_active_model
        setup_dependents
        setup_accel_group
        setup_popups
        setup_window_events
        setup_dialog_hooks
        setup_books_iconview_sorting
        on_books_selection_changed
        restore_preferences
        log.debug { "UI Manager initialized: #{@iconview.model.inspect}" }
        @clicking_on_sidepane = true

        @library_listview.signal_connect('cursor-changed') do
          @clicking_on_sidepane = true
        end
      end

      def show
        @main_app.show
      end

      def widget_names
        [:main_app, :paned, :vbox1, :library_listview,
         :notebook, :iconview, :listview, :status_label, :appbar,
         :progressbar]
      end

      def create_uimanager
        log.debug { 'Adding actiongroup to uimanager' }
        @uimanager = Gtk::UIManager.new
        @uimanager.insert_action_group(@actiongroup, 0)
      end

      def setup_dependents
        @listview_model = Gtk::TreeModelSort.new(@filtered_model)
        @iconview_model = Gtk::TreeModelSort.new(@filtered_model)
        @listview_manager = ListViewManager.new @listview, self
        @iconview_manager = IconViewManager.new @iconview, self
        @sidepane_manager = SidePaneManager.new @library_listview, self
        @library_listview = @sidepane_manager.library_listview
        @listview_manager.setup_listview_columns_visibility
        @listview_manager.setup_listview_columns_width
      end

      def setup_callbacks
        require 'alexandria/ui/callbacks'
        self.class.send(:include, Callbacks)
        connect_signals
      end

      def get_preferences
        @prefs = Preferences.instance
      end

      def setup_toolbar
        log.debug { 'setup_toolbar' }
        setup_book_providers
        add_main_toolbar_items
        @toolbar = @uimanager.get_widget('/MainToolbar')
        @toolbar.show_arrow = true
        @toolbar.insert(-1, Gtk::SeparatorToolItem.new)
        setup_toolbar_combobox
        setup_toolbar_filter_entry
        @toolbar.insert(-1, Gtk::SeparatorToolItem.new)
        setup_toolbar_viewas
        @toolbar.show_all
        @actiongroup['Undo'].sensitive = @actiongroup['Redo'].sensitive = false
        UndoManager.instance.add_observer(self)
        @vbox1.add(@toolbar,  position: 1, expand: false, fill: false)
      end

      def add_main_toolbar_items
        mid = @uimanager.new_merge_id
        @uimanager.add_ui(mid, 'ui/', 'MainToolbar', 'MainToolbar',
                          Gtk::UIManager::TOOLBAR, false)
        @uimanager.add_ui(mid, 'ui/MainToolbar/', 'New', 'New',
                          Gtk::UIManager::TOOLITEM, false)
        @uimanager.add_ui(mid, 'ui/MainToolbar/', 'AddBook', 'AddBook',
                          Gtk::UIManager::TOOLITEM, false)
        # @uimanager.add_ui(mid, "ui/MainToolbar/", "sep", "sep",
        #                  Gtk::UIManager::SEPARATOR, false)
        # @uimanager.add_ui(mid, "ui/MainToolbar/", "Refresh", "Refresh",
        #                  Gtk::UIManager::TOOLITEM, false)
      end

      def setup_toolbar_filter_entry
        @filter_entry = Gtk::Entry.new
        @filter_entry.signal_connect('changed', &method(:on_toolbar_filter_entry_changed))
        @toolitem = Gtk::ToolItem.new
        @toolitem.expand = true
        @toolitem.border_width = 5
        @tooltips.set_tip(@filter_entry,
                          _('Type here the search criterion'), nil)
        @toolitem << @filter_entry
        @toolbar.insert(-1, @toolitem)
      end

      def setup_toolbar_combobox
        @tooltips = Gtk::Tooltips.new

        cb = Gtk::ComboBox.new
        cb.set_row_separator_func do |_model, iter|
          # log.debug { "row_separator" }
          iter[0] == '-'
        end
        [_('Match everything'),
         '-',
         _('Title contains'),
         _('Authors contain'),
         _('ISBN contains'),
         _('Publisher contains'),
         _('Notes contain'),
         _('Tags contain')
        ].each do |item|
          cb.append_text(item)
        end
        cb.active = 0
        cb.signal_connect('changed', &method(:on_criterion_combobox_changed))

        # Put the combo box in a event box because it is not currently
        # possible assign a tooltip to a combo box.
        eb = Gtk::EventBox.new
        eb << cb
        @toolitem = Gtk::ToolItem.new
        @toolitem.border_width = 5
        @toolitem << eb
        @toolbar.insert(-1, @toolitem)
        @tooltips.set_tip(eb, _('Change the search type'), nil)
      end

      def setup_toolbar_viewas
        @toolbar_view_as = Gtk::ComboBox.new
        @toolbar_view_as.append_text(_('View as Icons'))
        @toolbar_view_as.append_text(_('View as List'))
        @toolbar_view_as.active = 0
        @toolbar_view_as_signal_hid = \
          @toolbar_view_as.signal_connect('changed', &method(:on_toolbar_view_as_changed))

        # Put the combo box in a event box because it is not currently
        # possible assign a tooltip to a combo box.
        eb = Gtk::EventBox.new
        eb << @toolbar_view_as
        @toolitem = Gtk::ToolItem.new
        @toolitem.border_width = 5
        @toolitem << eb
        @toolbar.insert(-1, @toolitem)
        @tooltips.set_tip(eb, _('Choose how to show books'), nil)
      end

      def setup_book_providers
        log.debug { 'setup_book_providers' }
        mid = @uimanager.new_merge_id
        BookProviders.each do |provider|

          name = provider.action_name
          ['ui/MainMenubar/ViewMenu/OnlineInformation/',
           'ui/BookPopup/OnlineInformation/',
           'ui/NoBookPopup/OnlineInformation/'].each do |path|
             log.debug { "Adding #{name} to #{path}" }
             @uimanager.add_ui(mid, path, name, name,
                               Gtk::UIManager::MENUITEM, false)
           end
        end
      end

      def add_menus_and_popups_from_xml
        log.debug { 'add_menus_and_popups_from_xml' }
        ['menus.xml', 'popups.xml'].each do |ui_file|
          @uimanager.add_ui(File.join(Alexandria::Config::DATA_DIR,
                                      'ui', ui_file))
        end
      end

      def setup_accel_group
        log.debug { 'setup_accel_group' }
        @main_app.add_accel_group(@uimanager.accel_group)
      end

      def setup_menus
        @menubar = @uimanager.get_widget('/MainMenubar')
        @vbox1.add(@menubar,  position: 0, expand: false, fill: false)
      end

      def setup_dialog_hooks
        log.debug { 'setup_dialog_hooks' }
        Gtk::AboutDialog.set_url_hook do |_about, link|
          log.debug { 'set_url_hook' }
          open_web_browser(link)
        end
        Gtk::AboutDialog.set_email_hook do |_about, link|
          log.debug { 'set_email_hook' }
          open_email_client('mailto:' + link)
        end
      end

      def setup_popups
        log.debug { 'setup_popups' }
        @library_popup = @uimanager.get_widget('/LibraryPopup')
        @smart_library_popup = @uimanager.get_widget('/SmartLibraryPopup')
        @nolibrary_popup = @uimanager.get_widget('/NoLibraryPopup')
        @book_popup = @uimanager.get_widget('/BookPopup')
        @nobook_popup = @uimanager.get_widget('/NoBookPopup')
      end

      def setup_window_events
        log.debug { 'setup_window_events' }
        @main_app.signal_connect('window-state-event', &method(:on_window_state_event))
        @main_app.signal_connect('destroy', &method(:on_window_destroy))
      end

      def setup_active_model
        log.debug { 'setting up active model' }
        # The active model.

        list = [
          Gdk::Pixbuf,    # COVER_LIST
          Gdk::Pixbuf,    # COVER_ICON
          String,         # TITLE
          String,         # TITLE_REDUCED
          String,         # AUTHORS
          String,         # ISBN
          String,         # PUBLISHER
          String,         # PUBLISH_DATE
          String,         # EDITION
          Integer,        # RATING
          String,         # IDENT
          String,         # NOTES
          TrueClass,      # REDD
          TrueClass,      # OWN
          TrueClass,      # WANT
          String,         # TAGS
          String          # LOANED TO
        ]

        @model = Gtk::ListStore.new(*list)

        # Filter books according to the search toolbar widgets.
        @filtered_model = Gtk::TreeModelFilter.new(@model)
        @filtered_model.set_visible_func do |_model, iter|
          # log.debug { "visible_func" }
          @filter_books_mode ||= 0
          filter = @filter_entry.text
          if filter.empty?
            true
          else
            data = case @filter_books_mode
                   when 0 then
                     (iter[Columns::TITLE] or '') +
                       (iter[Columns::AUTHORS] or '') +
                       (iter[Columns::ISBN] or '') +
                       (iter[Columns::PUBLISHER] or '') +
                       (iter[Columns::NOTES] or '') +
                       (iter[Columns::TAGS] or '')
                   when 2 then iter[Columns::TITLE]
                   when 3 then iter[Columns::AUTHORS]
                   when 4 then iter[Columns::ISBN]
                   when 5 then iter[Columns::PUBLISHER]
                   when 6 then iter[Columns::NOTES]
                   when 7 then iter[Columns::TAGS]
                   end
            !data.nil? and data.downcase.include?(filter.downcase)
          end
        end

        # Give filter entry the initial keyboard focus.
        @filter_entry.grab_focus
        log.debug { 'done setting up active model' }
      end

      def on_library_button_press_event(widget, event)
        log.debug { 'library_button_press_event' }

        # right click
        if event_is_right_click event
          log.debug { 'library right click!' }
          library_already_selected = true
          if (path = widget.get_path_at_pos(event.x, event.y))
            @clicking_on_sidepane = true
            obj, path = widget.is_a?(Gtk::TreeView) ? [widget.selection, path.first] : [widget, path]
            widget.has_focus = true

            unless obj.path_is_selected?(path)

              log.debug { "Select #{path}" }
              library_already_selected = false
              widget.unselect_all
              obj.select_path(path)
              sensitize_library selected_library

              if widget.is_a?(Gtk::TreeView)
                Gtk.idle_add do
                  # cur_path, focus_col = widget.cursor

                  widget.focus = true

                  widget.set_cursor(path, nil, false)
                  widget.grab_focus
                  widget.has_focus = true
                  false
                end
                # widget.has_focus = true
              end

              # library_already_selected = true
            end
          else
            widget.unselect_all
          end

          menu = determine_library_popup widget, event

          # Fixes part of bug #25021.
          #
          # If the library was not selected when it was right-clicked
          # we should select the library first (we call on_focus
          # manually, since the above call to obj.select_path(path) doesn't
          # seem to suffice).
          #
          # Then we wait a while and only *then* pop up the menu.

          if library_already_selected
            sensitize_library selected_library

            Gtk.idle_add do
              menu.popup(nil, nil, event.button, event.time)
              # @clicking_on_sidepane = false
              false
            end
          else
            Gtk.idle_add do
              menu.popup(nil, nil, event.button, event.time)
              # @clicking_on_sidepane = false

              false
            end
          end

        else
          # not a right click
          if (path = widget.get_path_at_pos(event.x, event.y))
            @clicking_on_sidepane = true
            obj, path = widget.is_a?(Gtk::TreeView) ? [widget.selection, path.first] : [widget, path]
            obj.select_path(path)
            sensitize_library selected_library

          end

        end
      end

      def determine_library_popup(widget, event)
        # widget.grab_focus
        widget.get_path_at_pos(event.x, event.y).nil? ? @nolibrary_popup : selected_library.is_a?(SmartLibrary) ? @smart_library_popup : @library_popup
      end

      def event_is_right_click(event)
        event.event_type == Gdk::Event::BUTTON_PRESS and event.button == 3
      end

      def on_books_button_press_event(widget, event)
        log.debug { 'books_button_press_event' }
        if event_is_right_click event
          widget.grab_focus

          if (path = widget.get_path_at_pos(event.x.to_i, event.y.to_i))
            obj, path = widget.is_a?(Gtk::TreeView) ? [widget.selection, path.first] : [widget, path]

            unless obj.path_is_selected?(path)
              log.debug { "Select #{path}" }
              widget.unselect_all
              obj.select_path(path)
            end
          else
            widget.unselect_all
          end

          menu = (selected_books.empty?) ? @nobook_popup : @book_popup
          menu.popup(nil, nil, event.button, event.time)
        end
      end

      def get_library_selection_text(library)
        case library.length
        when 0
          _("Library '%s' selected") % library.name

        else
          n_unrated = library.n_unrated
          if n_unrated == library.length
            n_("Library '%s' selected, %d unrated book",
               "Library '%s' selected, %d unrated books",
               library.length) % [library.name,
                                  library.length]
          elsif n_unrated == 0
            n_("Library '%s' selected, %d book",
               "Library '%s' selected, %d books",
               library.length) % [library.name,
                                  library.length]
          else
            n_("Library '%s' selected, %d book, " \
               '%d unrated',
               "Library '%s' selected, %d books, " \
               '%d unrated',
               library.length) % [library.name,
                                  library.length,
                                  n_unrated]
          end
        end
      end

      def get_appbar_status(library, books)
        case books.length
        when 0
          get_library_selection_text library
        when 1
          _("'%s' selected") % books.first.title
        else
          n_('%d book selected', '%d books selected',
             books.length) % books.length
        end
      end

      def set_status_label(txt)
        @status_label.text = txt
      end

      def on_books_selection_changed
        library = selected_library
        books = selected_books
        set_status_label(get_appbar_status(library, books))
        # selection = @library_listview.selection.selected ? @library_listview.selection.selected.has_focus? : false

        # Focus is the wrong idiom here.
        unless @clicking_on_sidepane or (@main_app.focus == @library_listview)
          # unless @main_app.focus == @library_listview

          log.debug { "Currently focused widget: #{@main_app.focus.inspect}" }
          log.debug { "#{@library_listview} : #{@library_popup} : #{@listview}" }
          log.debug { "@library_listview: #{@library_listview.has_focus?} or @library_popup:#{@library_popup.has_focus?}" } # or selection: #{selection}"}
          log.debug { '@library_listview does *NOT* have focus' }
          log.debug { "Books are empty: #{books.empty?}" }
          @actiongroup['Properties'].sensitive = \
            @actiongroup['OnlineInformation'].sensitive = \
            books.length == 1
          @actiongroup['SelectAll'].sensitive = \
            books.length < library.length

          @actiongroup['Delete'].sensitive = \
            @actiongroup['DeselectAll'].sensitive = \
            @actiongroup['Move'].sensitive =
            @actiongroup['SetRating'].sensitive = !books.empty?

          log.debug { "on_books_selection_changed Delete: #{@actiongroup['Delete'].sensitive?}" }

          if library.is_a?(SmartLibrary)
            @actiongroup['Delete'].sensitive =
              @actiongroup['Move'].sensitive = false
          end

          # Sensitize providers URL
          if books.length == 1
            b = books.first
            # FIXME: Clean up endless negation in this logic
            no_urls = true
            BookProviders.each do |provider|
              has_no_url = true
              begin
                has_no_url = (b.isbn.nil? or b.isbn.strip.empty? or provider.url(b).nil?)
              rescue => ex
                log.warn { "Error determining URL from #{provider.name}; #{ex.message}" }
              end
              @actiongroup[provider.action_name].sensitive = !has_no_url
              no_urls = false unless has_no_url
            end
            if no_urls
              @actiongroup['OnlineInformation'].sensitive = false
            end
          end
        end
        @clicking_on_sidepane = false
      end

      def on_switch_page
        log.debug { 'on_switch_page' }
        @actiongroup['ArrangeIcons'].sensitive = @notebook.page == 0
        on_books_selection_changed
      end

      def on_focus(widget, _event_focus)
        if @clicking_on_sidepane or widget == @library_listview
          log.debug { 'on_focus: @library_listview' }
          Gtk.idle_add do
            %w(OnlineInformation SelectAll DeselectAll).each do |action|
              @actiongroup[action].sensitive = false
            end
            @actiongroup['Properties'].sensitive = selected_library.is_a?(SmartLibrary)
            @actiongroup['Delete'].sensitive = determine_delete_option
            false
          end
        else
          on_books_selection_changed
        end
      end

      def determine_delete_option
        sensitive = (@libraries.all_regular_libraries.length > 1 or selected_library.is_a?(SmartLibrary))
        sensitive
      end

      def on_close_sidepane
        log.debug { 'on_close_sidepane' }
        @actiongroup['Sidepane'].active = false
      end

      def select_a_book(book)
        select_this_book = proc do |bk, view|
          @filtered_model.refilter
          iter = iter_from_book bk
          unless iter
            next
          end
          path = iter.path
          unless view.model
            next
          end
          path = view.model.convert_path_to_child_path(path)
          path = @filtered_model.convert_path_to_child_path(path)
          log.debug { "Path for #{bk.ident} is #{path}" }
          selection = view.respond_to?(:selection) ? @listview.selection : @iconview
          selection.unselect_all
          selection.select_path(path)
        end
        begin
          log.debug { 'select_a_book: listview' }
          select_this_book.call(book, @listview)
          log.debug { 'select_a_book: listview' }
          select_this_book.call(book, @iconview)
        rescue => ex
          trace = ex.backtrace.join("\n> ")
          log.warn { "Failed to automatically select book: #{ex.message} #{trace}" }
        end
        # TODO: Figure out why this frequently selects the wrong book!
      end

      def update(*ary)
        log.debug { "on_update #{ary}" }
        caller = ary.first
        if caller.is_a?(UndoManager)
          @actiongroup['Undo'].sensitive = caller.can_undo?
          @actiongroup['Redo'].sensitive = caller.can_redo?
        elsif caller.is_a?(Library)
          unless caller.updating?
            Gtk.queue do
              handle_update_caller_library ary
            end
          end
        else
          raise 'unrecognized update event'
        end
      end

      def handle_update_caller_library(ary)
        library, kind, book = ary
        if library == selected_library
          @iconview.freeze # This makes @iconview.model == nil
          @listview.freeze # NEW
          case kind
          when Library::BOOK_ADDED
            append_book(book)
          when Library::BOOK_UPDATED
            iter = iter_from_ident(book.saved_ident)
            if iter
              fill_iter_with_book(iter, book)
            end
          when Library::BOOK_REMOVED
            @model.remove(iter_from_book(book))
          end
          @iconview.unfreeze
          @listview.unfreeze # NEW
          select_a_book(book) if [Library::BOOK_ADDED, Library::BOOK_UPDATED].include? kind
        elsif selected_library.is_a?(SmartLibrary)
          refresh_books
        end
      end

      #######
      # private
      #######

      def open_web_browser(url)
        if url.nil?
          log.warn('Attempt to open browser with nil url')
          return
        end
        if (cmd = Preferences.instance.www_browser)
          launch_command = cmd
          if cmd.downcase.index('%u')
            launch_command = cmd.gsub(/%U/i, "\"" + url + "\"")
          else
            launch_command = cmd + " \"" + url + "\""
          end
          Thread.new { system(launch_command) }
        else
          ErrorDialog.new(@main_app,
                          _('Unable to launch the web browser'),
                          _('Check out that a web browser is ' \
                            'configured as default (Desktop ' \
                            'Preferences -> Advanced -> Preferred ' \
                            'Applications) and try again.'))
        end
      end

      def open_email_client(url)
        if (cmd = Preferences.instance.email_client)
          launch_command = cmd
          if cmd.downcase.index('%u')
            launch_command = cmd.gsub(/%u/i, "\"" + url + "\"")
          else
            launch_command = cmd + " \"" + url + "\""
          end
          Thread.new { system(launch_command) }
        else
          ErrorDialog.new(@main_app,
                          _('Unable to launch the mail reader'),
                          _('Check out that a mail reader is ' \
                            'configured as default (Desktop ' \
                            'Preferences -> Advanced -> Preferred ' \
                            'Applications) and try again.'))
        end
      end

      def detach_old_libraries
        log.debug { 'Un-observing old libraries' }
        @libraries.all_regular_libraries.each do |library|
          if library.is_a?(Library)
            library.delete_observer(self)
            @completion_models.remove_source(library)
          end
        end
      end

      def load_libraries
        log.info { 'Loading Libraries...' }
        @completion_models = CompletionModels.instance
        if @libraries
          detach_old_libraries
          @libraries.reload
        else
          @libraries = Libraries.instance
          @libraries.reload
          handle_ruined_books unless @libraries.ruined_books.empty?
        end
        @libraries.all_regular_libraries.each do |library|
          library.add_observer(self)
          @completion_models.add_source(library)
        end
      end

      def handle_ruined_books
        new_message = _("The data files for the following books are malformed or empty. Do you wish to attempt to download new information for them from the online book providers?\n")

        # message = _("These books do not conform to the ISBN-13
        # standard. We will attempt to replace them from the book
        # providers. Otherwise, we will turn them into manual
        # entries.\n" )

        @libraries.ruined_books.each { |bi|
          new_message += "\n#{bi[1] or bi[1].inspect}"
        }
        recovery_dialog = Gtk::MessageDialog.new(@main_app, Gtk::Dialog::MODAL,
                                                 Gtk::MessageDialog::WARNING,
                                                 Gtk::MessageDialog::BUTTONS_OK_CANCEL,
                                                 new_message).show
        recovery_dialog.signal_connect('response') do |_dialog, response_type|
          recovery_dialog.destroy
          if response_type == Gtk::Dialog::RESPONSE_OK
            # progress indicator...
            @progressbar.fraction = 0
            @appbar.children.first.visible = true   # show the progress bar

            total_book_count = @libraries.ruined_books.size
            fraction_per_book = 1.0 / total_book_count
            prog_percentage = 0

            @libraries.ruined_books.reverse!
            Gtk.idle_add do
              ruined_book = @libraries.ruined_books.pop
              if ruined_book
                book, isbn, library = ruined_book
                begin
                  book_rslt = Alexandria::BookProviders.isbn_search(isbn.to_s)
                  book = book_rslt[0]
                  cover_uri = book_rslt[1]

                  # TODO if the book was saved okay, make sure the old
                  # empty yaml file doesn't stick around esp if doing
                  # isbn-10 --> isbn-13 conversion...
                  if isbn.size == 10
                    filename = library.yaml(isbn)
                    log.debug { "removing old file #{filename}" }
                    begin
                      File.delete(filename)
                    rescue => ex
                      log.error { "Could not delete empty file #{filename}" }
                    end
                  end

                  log.debug { "Trying to add #{book.title}, #{cover_uri} in library ''#{library.name}'" }
                  unless cover_uri.nil?
                    library.save_cover(book, cover_uri)
                  end
                  library << book
                  library.save(book)
                  set_status_label(_("Added '%s' to library '%s'") % [book.title, library.name])

                rescue => ex
                  log.error { "Couldn't add book #{isbn}: #{ex}" }
                  log.error { ex.backtrace.join("\n") }
                end

                prog_percentage += fraction_per_book
                @progressbar.fraction = prog_percentage

                true
              else
                ## Totally copied and pasted from refresh_books...
                ## call this the second strike... (CathalMagus)

                # @iconview.unfreeze
                # @filtered_model.refilter
                # @listview.columns_autosize

                @progressbar.fraction = 1
                ## Hide the progress bar.
                @appbar.children.first.visible = false
                ## Refresh the status bar.
                set_status_label('')
                # on_books_selection_changed
                false
              end
            end
          end
        end
      end

      def cache_scaled_icon(icon, width, height)
        log.debug { "cache_scaled_icon #{icon}, #{width}, #{height}" }
        @cache ||= {}
        @cache[[icon, width, height]] ||= icon.scale(width, height)
      end

      ICON_TITLE_MAXLEN = 20   # characters
      ICON_HEIGHT = 90         # pixels
      REDUCE_TITLE_REGEX = Regexp.new("^(.{#{ICON_TITLE_MAXLEN}}).*$")

      def fill_iter_with_book(iter, book)
        log.debug { "fill iter #{iter} with book #{book}" }
        iter[Columns::IDENT] = book.ident.to_s
        iter[Columns::TITLE] = book.title
        title = book.title.sub(REDUCE_TITLE_REGEX, '\1...')
        iter[Columns::TITLE_REDUCED] = title
        iter[Columns::AUTHORS] = book.authors.join(', ')
        iter[Columns::ISBN] = book.isbn.to_s
        iter[Columns::PUBLISHER] = book.publisher
        iter[Columns::PUBLISH_DATE] = book.publishing_year.to_s
        iter[Columns::EDITION] = book.edition
        iter[Columns::NOTES] = (book.notes or '')
        iter[Columns::LOANED_TO] = (book.loaned_to or '')
        rating = (book.rating or Book::DEFAULT_RATING)
        iter[Columns::RATING] = MAX_RATING_STARS - rating # ascending order is the default
        iter[Columns::OWN] = book.own?
        iter[Columns::REDD] = book.redd?
        iter[Columns::WANT] = book.want?
        if book.tags
          iter[Columns::TAGS] = book.tags.join(',')
        else
          iter[Columns::TAGS] = ''
        end

        icon = Icons.cover(selected_library, book)
        log.debug { "Setting icon #{icon} for book #{book.title}" }
        iter[Columns::COVER_LIST] = cache_scaled_icon(icon, 20, 25)

        if icon.height > ICON_HEIGHT
          new_width = icon.width / (icon.height / ICON_HEIGHT.to_f)
          new_height = [ICON_HEIGHT, icon.height].min
          icon = cache_scaled_icon(icon, new_width, new_height)
        end
        if rating == MAX_RATING_STARS
          icon = icon.tag(Icons::FAVORITE_TAG)
        end
        iter[Columns::COVER_ICON] = icon
        log.debug { 'Full iter: ' + (0..15).map { |num| iter[num].inspect }.join(', ') }
      end

      def append_book(book, _tail = nil)
        log.debug { @model.inspect }
        iter = @model.append
        log.debug { "iter == #{iter}" }
        if iter
          fill_iter_with_book(iter, book)
        else
          log.debug { '@model.append' }
          iter = @model.append
          fill_iter_with_book(iter, book)
          log.debug { "no iter for book #{book}" }
        end
        library = selected_library
        if library.deleted_books.include?(book)
          log.debug { "Stop! Don't delete this book! We re-added it!" }
          library.undelete(book)
          UndoManager.instance.push { undoable_delete(library, [book]) }
        end
        iter
      end

      def append_library(library, autoselect = false)
        log.debug { "append_library #{library.name}" }
        model = @library_listview.model
        is_smart = library.is_a?(SmartLibrary)
        if is_smart
          if @library_separator_iter.nil?
            @library_separator_iter = append_library_separator
          end
          iter = model.append
        else
          iter = if @library_separator_iter.nil?
                   model.append
                 else
                   model.insert_before(@library_separator_iter)
                 end
        end

        iter[0] = is_smart ? Icons::SMART_LIBRARY_SMALL : Icons::LIBRARY_SMALL
        iter[1] = library.name
        iter[2] = true      # editable?
        iter[3] = false     # separator?
        if autoselect
          @library_listview.set_cursor(iter.path,
                                       @library_listview.get_column(0),
                                       true)
          @actiongroup['Sidepane'].active = true
        end
        iter
      end

      def append_library_separator
        log.debug { 'append_library_separator' }
        iter = @library_listview.model.append
        iter[0] = nil
        iter[1] = nil
        iter[2] = false     # editable?
        iter[3] = true      # separator?
        iter
      end

      def refresh_books
        log.debug { 'refresh_books' }
        @library_listview.set_sensitive(false)
        library = selected_library
        @model.clear
        @iconview.freeze
        @listview.freeze # NEW / bdewey
        @progressbar.fraction = 0
        @appbar.children.first.visible = true   # show the progress bar
        set_status_label(_("Loading '%s'...") % library.name)
        total = library.length
        log.debug { "library #{library.name} length #{library.length}" }
        n = 0

        Gtk.idle_add do

          block_return = true
          book = library[n]
          if book
            Gtk.queue do
              begin
                append_book(book)
              rescue => ex
                trace = ex.backtrace.join("\n > ")
                log.error { "append_books failed #{ex.message} #{trace}" }
              end
              # convert to percents
              coeff = total / 100.0
              percent = n / coeff
              fraction = percent / 100
              log.debug { "#index #{n} percent #{percent} fraction #{fraction}" }
              @progressbar.fraction = fraction
              n += 1
            end
          else
            Gtk.queue do
              @iconview.unfreeze
              @listview.unfreeze # NEW / bdewey
              @filtered_model.refilter
              @listview.columns_autosize
              @progressbar.fraction = 1
              # Hide the progress bar.
              @appbar.children.first.visible = false
              # Refresh the status bar.
              on_books_selection_changed
              @library_listview.set_sensitive(true)
              block_return = false
            end
          end

          block_return
        end
      end

      def selected_library
        log.debug { 'selected_library' }
        if (iter = @library_listview.selection.selected)
          @libraries.all_libraries.find { |x| x.name == iter[1] }
        else
          @libraries.all_libraries.first
        end
      end

      def select_library(library)
        log.debug { "select library #{library}" }
        iter = @library_listview.model.iter_first
        ok = true
        while ok
          if iter[1] == library.name
            @library_listview.selection.select_iter(iter)
            break
          end
          ok = iter.next!
        end
      end

      def book_from_iter(library, iter)
        log.debug { "Book from iter: #{library} #{iter}" }
        library.find { |x| x.ident == iter[Columns::IDENT] }
      end

      def iter_from_ident(ident)
        log.debug { "#{ident}" }
        iter = @model.iter_first
        ok = true
        while ok
          if iter[Columns::IDENT] == ident
            return iter
          end
          ok = iter.next!
        end
        nil
      end

      def iter_from_book(book)
        log.debug { "#{book}" }
        iter_from_ident(book.ident)
      end

      def collate_selected_books(page)
        a = []
        library = selected_library
        view = page == 0 ? @iconview : @listview
        selection = page == 0 ? @iconview : @listview.selection

        selection.selected_each do |_the_view, path|
          # don't use the_view which is passed in by this block
          # as it doesn't consider the filtering for some reason
          # see bug #24568
          unless view.model
            next
          end
          path = view.model.convert_path_to_child_path(path)
          if path
            path = @filtered_model.convert_path_to_child_path(path)
            # FIX this sometimes returns a nil path for iconview...
            if path
              iter = @model.get_iter(path)
              if iter
                a << book_from_iter(library, iter)
              end
            end
            # This used to cause a crash when manually adding the first
            # book to a Library displayed in an Iconview
            # TODO find root cause of this
          end
        end
        a
      end

      def selected_books
        a = collate_selected_books(@notebook.page)
        selected = a.select { |x| !x.nil? }
        log.debug { "Selected books = #{selected.inspect}" }
        selected
      end

      def refresh_libraries
        log.debug { 'refresh_libraries' }
        library = selected_library

        # Change the application's title.
        @main_app.title = library.name + ' - ' + TITLE

        # Disable the selected library in the move libraries actions.
        @libraries.all_regular_libraries.each do |i_library|
          action = @actiongroup[i_library.action_name]
          if action
            action.sensitive = i_library != library
          end
        end
        sensitize_library library
      end

      def sensitize_library(library)
        smart = library.is_a?(SmartLibrary)
        log.debug { "sensitize_library: smartlibrary = #{smart}" }
        Gtk.idle_add do
          @actiongroup['AddBook'].sensitive = !smart
          @actiongroup['AddBookManual'].sensitive = !smart
          @actiongroup['Properties'].sensitive = smart
          can_delete = smart || (@libraries.all_regular_libraries.length > 1)
          @actiongroup['Delete'].sensitive = can_delete ## true #(@libraries.all_regular_libraries.length > 1)
          log.debug { "sensitize_library delete: #{@actiongroup['Delete'].sensitive?}" }
          false
        end
      end

      def get_view_actiongroup
        case @prefs.view_as
        when 0
          @actiongroup['AsIcons']
        when 1
          @actiongroup['AsList']
        end
      end

      def restore_preferences
        log.debug { 'Restoring preferences...' }
        if @prefs.maximized
          @main_app.maximize
        else
          @main_app.move(*@prefs.position) unless @prefs.position == [0, 0]
          @main_app.resize(*@prefs.size)
          @maximized = false
        end
        @paned.position = @prefs.sidepane_position
        @actiongroup['Sidepane'].active = @prefs.sidepane_visible
        @actiongroup['Toolbar'].active = @prefs.toolbar_visible
        @actiongroup['Statusbar'].active = @prefs.statusbar_visible
        @appbar.visible = @prefs.statusbar_visible
        action = get_view_actiongroup
        action.activate
        library = nil
        unless @prefs.selected_library.nil?
          library = @libraries.all_libraries.find do |x|
            x.name == @prefs.selected_library
          end
        end
        select_a_library library
      end

      def select_a_library(library)
        if library
          select_library(library)
        else
          # Select the first item by default.
          iter = @library_listview.model.iter_first
          @library_listview.selection.select_iter(iter)
        end
      end

      def save_preferences
        log.debug { 'save_preferences' }
        @prefs.position = @main_app.position
        @prefs.size = @main_app.allocation.to_a[2..3]
        @prefs.maximized = @maximized
        @prefs.sidepane_position = @paned.position
        @prefs.sidepane_visible = @actiongroup['Sidepane'].active?
        @prefs.toolbar_visible = @actiongroup['Toolbar'].active?
        @prefs.statusbar_visible = @actiongroup['Statusbar'].active?
        @prefs.view_as = @notebook.page
        @prefs.selected_library = selected_library.name
        cols_width = {}
        @listview.columns.each do |c|
          cols_width[c.title] = [c.widget.size_request.first, c.width].max
        end
        @prefs.cols_width = '{' + cols_width.to_a.map do |t, v|
          '"' + t + '": ' + v.to_s
        end.join(', ') + '}'
        log.debug { "cols_width: #{@prefs.cols_width} " }
        @prefs.save!
      end

      def undoable_move(source, dest, books)
        log.debug { 'undoable_move' }
        Library.move(source, dest, *books)
        UndoManager.instance.push { undoable_move(dest, source, books) }
      end

      def move_selected_books_to_library(library)
        books = selected_books.select do |book|
          !library.include?(book) or
            ConflictWhileCopyingDialog.new(@main_app,
                                           library,
                                           book).replace?
        end
        undoable_move(selected_library, library, books)
      end

      def setup_move_actions
        @actiongroup.actions.each do |action|
          next unless /^MoveIn/.match(action.name)
          @actiongroup.remove_action(action)
        end
        actions = []
        @libraries.all_regular_libraries.each do |library|
          actions << [
            library.action_name, nil,
            _("In '_%s'") % library.name,
            nil, nil, proc { move_selected_books_to_library(library) }
          ]
        end
        @actiongroup.add_actions(actions)
        @uimanager.remove_ui(@move_mid) if @move_mid
        @move_mid = @uimanager.new_merge_id
        @libraries.all_regular_libraries.each do |library|
          name = library.action_name
          ['ui/MainMenubar/EditMenu/Move/',
           'ui/BookPopup/Move/'].each do |path|
            @uimanager.add_ui(@move_mid, path, name, name,
                              Gtk::UIManager::MENUITEM, false)
          end
        end
      end

      def current_view
        case @notebook.page
        when 0
          @iconview
        when 1
          @listview
        end
      end

      # Gets the sort order of the current library, for use by export
      def library_sort_order
        # added by Cathal Mc Ginley, 23 Oct 2007
        log.debug { "library_sort_order #{@notebook.page}: #{@iconview.model.inspect} #{@listview.model.inspect}" }
        sorted_on = current_view.model.sort_column_id
        if sorted_on
          sort_column = sorted_on[0]
          sort_order = sorted_on[1]

          column_ids_to_attributes = { 2 => :title,
                                       4 => :authors,
                                       5 => :isbn,
                                       6 => :publisher,
                                       7 => :publishing_year,
                                       8 => :edition, # binding
                                       12 => :redd,
                                       13 => :own,
                                       14 => :want,
                                       9 => :rating }

          sort_attribute = column_ids_to_attributes[sort_column]
          ascending = (sort_order == Gtk::SORT_ASCENDING)
          LibrarySortOrder.new(sort_attribute, ascending)
        else
          LibrarySortOrder::Unsorted.new
        end
      end

      def get_previous_selected_library(library)
        log.debug { "get_previous_selected_library: #{library}" }
        @previous_selected_library = selected_library
        if @previous_selected_library != library
          select_library(library)
        else
          @previous_selected_library = nil
        end
      end

      def remove_library_iter
        old_iter = @library_listview.selection.selected
        # commenting out this code seems to fix #20681
        # "crashes when switching to smart library mid-load"
        # next_iter = @library_listview.selection.selected
        # next_iter.next!
        @library_listview.model.remove(old_iter)
        # @library_listview.selection.select_iter(next_iter)
      end

      def undoable_delete(library, books = nil)
        # Deleting a library.
        if books.nil?
          library.delete_observer(self) if library.is_a?(Library)
          library.delete
          @libraries.remove_library(library)
          remove_library_separator
          remove_library_iter
          get_previous_selected_library library
          setup_move_actions
          select_library(@previous_selected_library) unless @previous_selected_library.nil?
          @previous_selected_library = nil
        else
          # Deleting books.
          books.each { |book| library.delete(book) }
        end
        UndoManager.instance.push { undoable_undelete(library, books) }
      end

      def remove_library_separator
        if !@library_separator_iter.nil? and @libraries.all_smart_libraries.empty?
          @library_listview.model.remove(@library_separator_iter)
          @library_separator_iter = nil
        end
      end

      def undoable_undelete(library, books = nil)
        # Undeleting a library.
        if books.nil?
          library.undelete
          @libraries.add_library(library)
          append_library(library)
          setup_move_actions
          library.add_observer(self) if library.is_a?(Library)
          # Undeleting books.
        else
          books.each { |book| library.undelete(book) }
        end
        select_library(library)
        UndoManager.instance.push { undoable_delete(library, books) }
      end

      def setup_window_icons
        @main_app.icon = Icons::ALEXANDRIA_SMALL
        Gtk::Window.set_default_icon_name('alexandria')
        @main_app.icon_name = 'alexandria'
      end

      ICONS_SORTS = [
        Columns::TITLE, Columns::AUTHORS, Columns::ISBN,
        Columns::PUBLISHER, Columns::EDITION, Columns::RATING, Columns::REDD, Columns::OWN, Columns::WANT
      ]

      def setup_books_iconview_sorting
        sort_order = @prefs.reverse_icons ? Gtk::SORT_DESCENDING : Gtk::SORT_ASCENDING
        mode = ICONS_SORTS[@prefs.arrange_icons_mode]
        @iconview_model.set_sort_column_id(mode, sort_order)
        @filtered_model.refilter # force redraw
      end
    end
  end
end