# Author::    Eric Crane  (mailto:eric.crane@mac.com)
# Copyright:: Copyright (c) 2019 Eric Crane.  All rights reserved.
#
# An object with an boolean value.
#

module Gloo
  module Objs
    class Boolean < Gloo::Core::Obj
      
      KEYWORD = 'boolean'
      KEYWORD_SHORT = 'bool'
      TRUE = 'true'
      FALSE = 'false'

      # 
      # The name of the object type.
      # 
      def self.typename
        return KEYWORD
      end

      # 
      # The short name of the object type.
      # 
      def self.short_typename
        return KEYWORD_SHORT
      end

      # 
      # Set the value with any necessary type conversions.
      # 
      def set_value new_value
        self.value = Gloo::Objs::Boolean.coerse_to_bool( new_value )
      end
      
      # 
      # Coerse the new value to a boolean value.
      # 
      def self.coerse_to_bool new_value
        if new_value.nil?
          return false
        elsif new_value.class.name == "String"
          return true if new_value.strip.downcase == TRUE
          return false if new_value.strip.downcase == FALSE
          return true if new_value.strip.downcase == 't'
          return false if new_value.strip.downcase == 'f'
        elsif new_value.class.name == "Integer"
          return false if new_value == 0
          return true
        else
          return new_value == true
        end
      end
      
      # 
      # Is the given token a boolean?
      # 
      def self.is_boolean? token
        return true if token == true
        return true if token == false
        if token.class.name == "String"
          return true if token.strip.downcase == TRUE
          return true if token.strip.downcase == FALSE
        end
        return false
      end

      
      # 
      # Get the value for display purposes.
      # 
      def value_display
        return value ? TRUE : FALSE
      end

      
      # ---------------------------------------------------------------------
      #    Messages
      # ---------------------------------------------------------------------

      # 
      # Get a list of message names that this object receives.
      # 
      def self.messages
        return super + [ "not", "true", "false" ]
      end
      
      # Set the value to the opposite of what it is.
      def msg_not
        v = ! value
        set_value v
        $engine.heap.it.set_to v
        return v
      end

      # Set the value to true.
      def msg_true
        set_value true
        $engine.heap.it.set_to true
        return true
      end

      # Set the value to false.
      def msg_false
        set_value false
        $engine.heap.it.set_to false
        return false
      end

    end
  end
end