class ViewModel::Changes

def ==(other)
  return false unless other.is_a?(ViewModel::Changes)
  self.new? == other.new? &&
    self.changed_nested_children? == other.changed_nested_children? &&
    self.changed_referenced_children? == other.changed_referenced_children? &&
    self.deleted? == other.deleted? &&
    self.changed_attributes.contains_exactly?(other.changed_attributes) &&
    self.changed_associations.contains_exactly?(other.changed_associations)
end

def changed?
  new? || deleted? || changed_attributes.present? || changed_associations.present?
end

def changed_any?(associations: [], attributes: [])
  associations.any? { |assoc| changed_associations.include?(assoc.to_s) } ||
    attributes.any? { |attr| changed_attributes.include?(attr.to_s) }
end

def changed_nested_tree?
  changed? || changed_nested_children?
end

def changed_owned_tree?
  changed? || changed_nested_children? || changed_referenced_children?
end

def contained_to?(associations: [], attributes: [])
  !deleted? &&
    changed_associations.all? { |assoc| associations.include?(assoc.to_s) } &&
    changed_attributes.all? { |attr| attributes.include?(attr.to_s) }
end

def initialize(new: false, changed_attributes: [], changed_associations: [], changed_nested_children: false, changed_referenced_children: false, deleted: false)
  @new                         = new
  @changed_attributes          = changed_attributes.map(&:to_s)
  @changed_associations        = changed_associations.map(&:to_s)
  @changed_nested_children     = changed_nested_children
  @changed_referenced_children = changed_referenced_children
  @deleted                     = deleted
end

def to_h
  {
    'changed_attributes'          => changed_attributes.dup,
    'changed_associations'        => changed_associations.dup,
    'new'                         => new?,
    'changed_nested_children'     => changed_nested_children?,
    'changed_referenced_children' => changed_referenced_children?,
    'deleted'                     => deleted?,
  }
end