module Audited::Auditor::AuditedInstanceMethods

def audit_create
  write_audit(:action => 'create', :audited_changes => audited_attributes,
              :comment => audit_comment)
end

def audit_destroy
  write_audit(:action => 'destroy', :audited_changes => audited_attributes,
              :comment => audit_comment)
end

def audit_update
  unless (changes = audited_changes).empty? && audit_comment.blank?
    write_audit(:action => 'update', :audited_changes => changes,
                :comment => audit_comment)
  end
end

def audited_attributes
  attributes.except(*non_audited_columns)
end

def audited_changes
  changed_attributes.except(*non_audited_columns).inject({}) do |changes,(attr, old_value)|
    changes[attr] = [old_value, self[attr]]
    changes
  end
end

def audits_to(version = nil)
  if version == :previous
    version = if self.version
                self.version - 1
              else
                previous = audits.descending.offset(1).first
                previous ? previous.version : 1
              end
  end
  audits.to_version(version)
end

def empty_callback #:nodoc:
end

def require_comment
  if auditing_enabled && audit_comment.blank?
    errors.add(:audit_comment, "Comment required before destruction")
    return false
  end
end

def revision(version)
  revision_with Audited.audit_class.reconstruct_attributes(audits_to(version))
end

def revision_at(date_or_time)
  audits = self.audits.up_until(date_or_time)
  revision_with Audited.audit_class.reconstruct_attributes(audits) unless audits.empty?
end

def revision_with(attributes)
  self.dup.tap do |revision|
    revision.id = id
    revision.send :instance_variable_set, '@attributes', self.attributes
    revision.send :instance_variable_set, '@new_record', self.destroyed?
    revision.send :instance_variable_set, '@persisted', !self.destroyed?
    revision.send :instance_variable_set, '@readonly', false
    revision.send :instance_variable_set, '@destroyed', false
    revision.send :instance_variable_set, '@_destroyed', false
    revision.send :instance_variable_set, '@marked_for_destruction', false
    Audited.audit_class.assign_revision_attributes(revision, attributes)
    # Remove any association proxies so that they will be recreated
    # and reference the correct object for this revision. The only way
    # to determine if an instance variable is a proxy object is to
    # see if it responds to certain methods, as it forwards almost
    # everything to its target.
    for ivar in revision.instance_variables
      proxy = revision.instance_variable_get ivar
      if !proxy.nil? and proxy.respond_to? :proxy_respond_to?
        revision.instance_variable_set ivar, nil
      end
    end
  end
end

def revisions(from_version = 1)
  audits = self.audits.from_version(from_version)
  return [] if audits.empty?
  revisions = []
  audits.each do |audit|
    revisions << audit.revision
  end
  revisions
end

def save_without_auditing
  without_auditing { save }
end

def without_auditing(&block)
  self.class.without_auditing(&block)
end

def write_audit(attrs)
  attrs[:associated] = self.send(audit_associated_with) unless audit_associated_with.nil?
  self.audit_comment = nil
  run_callbacks(:audit)  { self.audits.create(attrs) } if auditing_enabled
end