# Copyright (c) 2007-2021 Andy Maleh
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

require 'glimmer/swt/swt_proxy'
require 'glimmer/swt/widget_proxy'
require 'glimmer/swt/display_proxy'

module Glimmer
  module SWT
    # Proxy for org.eclipse.swt.widgets.Shell
    #
    # Follows the Proxy Design Pattern
    class ShellProxy < WidgetProxy
      include_package 'org.eclipse.swt.widgets'
      include_package 'org.eclipse.swt.layout'

      WIDTH_MIN = 190
      HEIGHT_MIN = 0

      attr_reader :opened_before, :last_shell_closing
      alias last_shell_closing? last_shell_closing
      alias opened_before? opened_before

      # Instantiates ShellProxy with same arguments expected by SWT Shell
      # if swt_widget keyword arg was passed, then it is assumed the shell has already been instantiated
      # and the proxy wraps it instead of creating a new one.
      def initialize(*args, swt_widget: nil)
        auto_exec do
          if swt_widget
            @swt_widget = swt_widget
          else
            if args.first.respond_to?(:swt_widget) && args.first.swt_widget.is_a?(Shell)
              @parent_proxy = args[0]
              args[0] = args[0].swt_widget
            end
            style_args = args.select {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}.map(&:to_sym)
            fill_screen = nil
            if style_args.include?(:fill_screen)
              args.delete(:fill_screen)
              style_args.delete(:fill_screen)
              fill_screen = true
            end
            if style_args.any?
              style_arg_start_index = args.index(style_args.first)
              style_arg_last_index = args.index(style_args.last)
              args[style_arg_start_index..style_arg_last_index] = SWTProxy[style_args]
            end
            if args.first.nil? || (!args.first.is_a?(Display) && !args.first.is_a?(Shell))
              @display = DisplayProxy.instance.swt_display
              args = [@display] + args
            end
            args = args.compact
            @swt_widget = Shell.new(*args)
            @swt_widget.set_data('proxy', self)
            @swt_widget.setLayout(FillLayout.new)
            @swt_widget.setMinimumSize(WIDTH_MIN, HEIGHT_MIN)
            # TODO make this an option not the default
            shell_swt_display = Glimmer::SWT::DisplayProxy.instance.swt_display
            on_swt_show do
              if @filled_screen.nil? && fill_screen # only the first time
                @swt_widget.set_size(@display.bounds.width, @display.bounds.height)
              end
              Thread.new do
                sleep(0.25)
                shell_swt_display.async_exec do
                  @swt_widget.setActive unless @swt_widget.isDisposed
                end
              end
            end
          end
          on_widget_disposed do
            @last_shell_closing = true if @display.shells.count == 1 && @display.shells.first == @swt_widget
            clear_shapes unless @last_shell_closing
          end
          @display ||= @swt_widget.getDisplay
        end
      end

      # Centers shell within monitor it is in
      def center_within_display
        auto_exec do
          primary_monitor = @display.getPrimaryMonitor()
          monitor_bounds = primary_monitor.getBounds()
          shell_bounds = @swt_widget.getBounds()
          location_x = monitor_bounds.x + (monitor_bounds.width - shell_bounds.width) / 2
          location_y = monitor_bounds.y + (monitor_bounds.height - shell_bounds.height) / 2
          @swt_widget.setLocation(location_x, location_y)
        end
      end

      # Opens shell and starts SWT's UI thread event loop
      def open
        open_only
        start_event_loop unless nested?
      end
      alias show open
      
      # Opens without starting the event loop.
      def open_only
        auto_exec do
          if @opened_before
            @swt_widget.setVisible(true)
          else
            @opened_before = true
            @swt_widget.pack
            center_within_display
            @swt_widget.open
          end
        end
      end
      
      def nested?
        auto_exec do
          !swt_widget&.parent.nil?
        end
      end
      alias nested nested?
      
      def disposed?
        swt_widget.isDisposed
      end
      alias disposed disposed?

      # Hides shell. Automatically checks if widget is disposed to avoid crashing.
      def hide
        auto_exec do
          @swt_widget.setVisible(false) unless @swt_widget.isDisposed
        end
      end
      
      # Closes shell. Automatically checks if widget is disposed to avoid crashing.
      def close
        auto_exec do
          @swt_widget.close unless @swt_widget.isDisposed
        end
      end

      def visible?
        auto_exec do
          @swt_widget.isDisposed ? false : @swt_widget.isVisible
        end
      end
      alias visible visible?

      # Setting to true opens/shows shell. Setting to false hides the shell.
      def visible=(visibility)
        visibility ? show : hide
      end
      
      def include_focus_control?
        DisplayProxy.instance.focus_control&.shell == swt_widget
      end

      def pack_same_size
        auto_exec do
          bounds = @swt_widget.getBounds
          if OS.mac?
            @swt_widget.pack
            @swt_widget.setBounds(bounds)
          elsif OS.windows? || OS::Underlying.windows?
            minimum_size = @swt_widget.getMinimumSize
            @swt_widget.setMinimumSize(bounds.width, bounds.height)
            listener = on_control_resized { @swt_widget.setBounds(bounds) }
            @swt_widget.layout(true, true)
            @swt_widget.removeControlListener(listener.swt_listener)
            @swt_widget.setMinimumSize(minimum_size)
          elsif OS.linux?
            @swt_widget.layout(true, true)
            @swt_widget.setBounds(bounds)
          end
        end
      end

      def content(&block)
        Glimmer::DSL::Engine.add_content(self, Glimmer::DSL::SWT::ShellExpression.new, 'shell', &block)
      end

      # (happens as part of `#open`)
      # Starts SWT Event Loop.
      #
      # You may learn more about the SWT Event Loop here:
      # https://help.eclipse.org/2019-12/nftopic/org.eclipse.platform.doc.isv/reference/api/org/eclipse/swt/widgets/Display.html
      # This method is not needed except in rare circumstances where there is a need to start the SWT Event Loop before opening the shell.
      def start_event_loop
        auto_exec do
          until @swt_widget.isDisposed
            begin
              @display.sleep unless @display.readAndDispatch
            rescue => e
              Glimmer::Config.logger.info {e.full_message}
            end
          end
        end
      end

      def add_observer(observer, property_name)
        case property_name.to_s
        when 'visible?' #TODO see if you must handle non-? version and/or move elsewhere
          visibility_notifier = proc do
            observer.call(visible?)
          end
          on_swt_show(&visibility_notifier)
          on_swt_hide(&visibility_notifier)
          on_swt_close(&visibility_notifier)
        else
          super
        end
      end
      
    end
    
    WindowProxy = ShellProxy
    
  end
  
end