module AASM::Persistence::ActiveRecordPersistence::InstanceMethods

def aasm_column_is_blank?(state_machine_name)
  attribute_name = self.class.aasm(state_machine_name).attribute_name
  attribute_names.include?(attribute_name.to_s) &&
    (send(attribute_name).respond_to?(:empty?) ? !!send(attribute_name).empty? : !send(attribute_name))
end

def aasm_column_looks_like_enum(name=:default)
  column_name = self.class.aasm(name).attribute_name.to_s
  column = self.class.columns_hash[column_name]
  raise NoMethodError.new("undefined method '#{column_name}' for #{self.class}") if column.nil?
  column.type == :integer
end

def aasm_ensure_initial_state
  AASM::StateMachineStore.fetch(self.class, true).machine_names.each do |state_machine_name|
    # checking via respond_to? does not work in Rails <= 3
    # if respond_to?(self.class.aasm(state_machine_name).attribute_name) && send(self.class.aasm(state_machine_name).attribute_name).blank? # Rails 4
    if aasm_column_is_blank?(state_machine_name)
      aasm(state_machine_name).enter_initial_state
    end
  end
end

def aasm_enum(name=:default)
  case AASM::StateMachineStore.fetch(self.class, true).machine(name).config.enum
  when false then nil
  when true then aasm_guess_enum_method(name)
  when nil then aasm_guess_enum_method(name) if aasm_column_looks_like_enum(name)
  else AASM::StateMachineStore.fetch(self.class, true).machine(name).config.enum
  end
end

def aasm_execute_after_commit
  begin
    require 'after_commit_everywhere'
    raise LoadError unless Gem::Version.new(::AfterCommitEverywhere::VERSION) >= Gem::Version.new('0.1.5')
    self.extend ::AfterCommitEverywhere
    after_commit do
      yield
    end
  rescue LoadError
    warn <<-MSG
CATION] :after_commit AASM callback is not safe in terms of race conditions and redundant calls.
        Please add `gem 'after_commit_everywhere', '~> 1.0'` to your Gemfile in order to fix that.
    MSG
    yield
  end
end

def aasm_guess_enum_method(name=:default)
  self.class.aasm(name).attribute_name.to_s.pluralize.to_sym
end

def aasm_invalid_state?(state_machine_name)
  aasm(state_machine_name).current_state && !aasm(state_machine_name).states.include?(aasm(state_machine_name).current_state)
end

def aasm_raise_invalid_record
  raise ActiveRecord::RecordInvalid.new(self)
end

def aasm_raw_attribute_value(state, name=:default)
  if aasm_enum(name)
    self.class.send(aasm_enum(name))[state]
  else
    super
  end
end

def aasm_read_attribute(name)
  read_attribute(name)
end

def aasm_save
  self.save
end

def aasm_transaction(requires_new, requires_lock)
  self.class.transaction(:requires_new => requires_new) do
    lock!(requires_lock) if requires_lock
    yield
  end
end

def aasm_update_column(attribute_name, value)
  self.class.unscoped.where(self.class.primary_key => self.id).update_all(attribute_name => value) == 1
end

def aasm_validate_states
  AASM::StateMachineStore.fetch(self.class, true).machine_names.each do |state_machine_name|
    unless aasm_skipping_validations(state_machine_name)
      if aasm_invalid_state?(state_machine_name)
        self.errors.add(AASM::StateMachineStore.fetch(self.class, true).machine(state_machine_name).config.column , "is invalid")
      end
    end
  end
end

def aasm_write_attribute(name, value)
  write_attribute(name, value)
end