class Dystruct

# File lib/dystruct.rb, line 10
def self.inherited(subclass)
  subclass.extend ClassMethods
  subclass.include InstanceMethods
end

# File lib/dystruct.rb, line 19
def initialize(hash = {})
  unless hash.class <= Hash
    fail WrongArgument, "[Dystruct ERROR]: `#{self.class}` expects to receive a `Hash` or and object having `Hash` as ancestor."
  end
  @attrs = hash
  @attrs.each do |k, v|
    define_dystruct_method(k, v)
  end
end

# File lib/dystruct.rb, line 29
def [](key)
  attrs[key]
end

# File lib/dystruct.rb, line 33
def []=(key, value)
  set_attribute(key, value)
end

# File lib/dystruct.rb, line 37
def method_missing(name, *args, &block)
  if name =~ /\A\w+=\z/
    set_attribute_macro(name, *args, &block)
  elsif out = provided_macro(name)
    out[:out]
  else
    super
  end
end

# File lib/dystruct.rb, line 67
def define_dystruct_method(key, value)
  define_singleton_method(key) { attrs.fetch(key) }
  define_singleton_method("#{key}_provided?") { true }
  define_singleton_method("#{key}_not_provided?") { false }
end

# File lib/dystruct.rb, line 55
def provided_macro(name)
  case name.to_s
  when /\A\w+_not_provided\?\z/ then { out: true }
  when /\A\w+_provided\?\z/ then { out: false }
  end
end

# File lib/dystruct.rb, line 62
def set_attribute(key, value)
  attrs[key] = value
  define_dystruct_method(key, value)
end

# File lib/dystruct.rb, line 49
def set_attribute_macro(name, *args, &block)
  value = args.first || block
  key = name.to_s.gsub('=', '').to_sym
  set_attribute(key, value)
end