# Copyright (c) 2020 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/data_binding/observable'
require 'glimmer/data_binding/observer'

module Glimmer
  module DataBinding
    module Tk
      # Tk List widget selection binding
      class ListSelectionBinding
        include Glimmer
        include Observable
        include Observer
  
        attr_reader :widget_proxy
  
        PROPERTY_TYPE_UPDATERS = {
          :string => lambda do |widget_proxy, value| 
            widget_proxy.selection = value.to_s
          end,
          :array => lambda do |widget_proxy, value| 
            widget_proxy.selection = (value || [])
          end
        }
  
        PROPERTY_EVALUATORS = {
          :string => lambda do |selection_array|
            return nil if selection_array.empty?
            selection_array.map(&:text)[0]
          end,
          :array => lambda do |selection_array|
            selection_array.map(&:text)
          end
        }
  
        # Initialize with list widget and property_type
        # property_type :string represents default list single selection
        # property_type :array represents list multi selection
        def initialize(widget_proxy)
          property_type = widget_proxy.selectmode == 'browse' ? :string : :array
          @widget_proxy = widget_proxy
          @property_type = property_type
        end
  
        def call(value)
          PROPERTY_TYPE_UPDATERS[@property_type].call(@widget_proxy, value) unless evaluate_property == value
        end
  
        def evaluate_property
          selection_array = @widget_proxy.tk.selection.to_a
          PROPERTY_EVALUATORS[@property_type].call(selection_array)
        end
      end
    end
  end
end