class Shoulda::Matchers::ActiveRecord::AcceptNestedAttributesForMatcher

def allow_destroy(allow_destroy)
  @options[:allow_destroy] = allow_destroy
  self
end

def allow_destroy_correct?
  failure_message = "#{should_or_should_not(@options[:allow_destroy])} allow destroy"
  verify_option_is_correct(:allow_destroy, failure_message)
end

def config
  model_config[@name]
end

def description
  description = "accepts_nested_attributes_for :#{@name}"
  if @options.key?(:allow_destroy)
    description += " allow_destroy => #{@options[:allow_destroy]}"
  end
  if @options.key?(:limit)
    description += " limit => #{@options[:limit]}"
  end
  if @options.key?(:update_only)
    description += " update_only => #{@options[:update_only]}"
  end
  description
end

def exists?
  if config
    true
  else
    @problem = 'is not declared'
    false
  end
end

def expectation
  "#{model_class.name} to accept nested attributes for #{@name}"
end

def failure_message_for_should
  "Expected #{expectation} (#{@problem})"
end

def failure_message_for_should_not
  "Did not expect #{expectation}"
end

def initialize(name)
  @name = name
  @options = {}
end

def limit(limit)
  @options[:limit] = limit
  self
end

def limit_correct?
  failure_message = "limit should be #{@options[:limit]}, got #{config[:limit]}"
  verify_option_is_correct(:limit, failure_message)
end

def matches?(subject)
  @subject = subject
  exists? &&
    allow_destroy_correct? &&
    limit_correct? &&
    update_only_correct?
end

def model_class
  @subject.class
end

def model_config
  model_class.nested_attributes_options
end

def should_or_should_not(value)
  if value
    'should'
  else
    'should not'
  end
end

def update_only(update_only)
  @options[:update_only] = update_only
  self
end

def update_only_correct?
  failure_message = "#{should_or_should_not(@options[:update_only])} be update only"
  verify_option_is_correct(:update_only, failure_message)
end

def verify_option_is_correct(option, failure_message)
  if @options.key?(option)
    if @options[option] == config[option]
      true
    else
      @problem = failure_message
      false
    end
  else
    true
  end
end