module Morph
  VERSION = "0.1.2"

  def self.included(base)
    base.extend ClassMethods
    base.send(:include, InstanceMethods)
  end

  module ClassMethods

    @@morph_methods = {}

    def convert_to_morph_method_name label
      name = label.downcase.tr('()*',' ').gsub('%','percentage').strip.chomp(':').strip.gsub(/\s/,'_').squeeze('_')
      name = '_'+name if name =~ /^\d/
      name
    end

    def morph_accessor symbol
      attribute = symbol.to_s
      @@morph_methods[attribute] = true
      @@morph_methods[attribute+'='] = true
      class_eval "attr_accessor :#{attribute}"
    end

    def morph_methods
      @@morph_methods.keys.sort
    end

    def remove_method symbol
      @@morph_methods.delete symbol.to_s
      super
    end

    def remove_morph_writers
      writers = morph_methods.select { |m| m =~ /=\Z/ }
      writers.each do |writer|
        class_eval "remove_method :#{writer}"
      end
    end

    def print_morph_methods
      methods = morph_methods
      writers = methods.select { |m| m =~ /=\Z/ }
      readers = methods.reject { |m| m =~ /=\Z/ }

      accessors = readers.select { |m| writers.include? "#{m}=" }
      readers =   readers.reject { |m| accessors.include? m }
      writers =   writers.reject { |m| accessors.include? m.chomp('=') }

      attributes = accessors.collect { |attribute| "attr_accessor :#{attribute}\n" }
      attributes += readers.collect {  |attribute| "attr_reader :#{attribute}\n" }
      attributes += writers.collect {  |attribute| "attr_writer :#{attribute}\n" }

      attributes.join.chop
    end
  end

  module InstanceMethods

    def morph label, value
      attribute = self.class.convert_to_morph_method_name label
      send("#{attribute}=".to_sym, value)
    end

    def method_missing symbol, *args
      is_writer = symbol.to_s =~ /=\Z/

      if is_writer
        attribute = symbol.to_s.chomp '='
        if Object.instance_methods.include?(attribute)
          raise "'#{attribute}' is an instance_method on Object, cannot create accessor methods for '#{attribute}'"
        elsif args.size > 0
          value = args[0]
          empty_value = (value.nil? or (value.is_a?(String) && value.strip.size == 0))
          unless empty_value
            self.class.morph_accessor attribute.to_sym
            send(symbol, *args)
          end
        end
      else
        super
      end
    end
  end
end