require 'active_record'
require 'yaml'

class GraphLabel < ActiveRecord::Base
  has_many :network_elements
end

class NetworkElement < ActiveRecord::Base
  belongs_to :graph_label
  validates_presence_of :graph_label_id
end

YAML.add_domain_type("yaml.org,2002", "") do |type, val|
  klass = type.split(":").last.constantize

  #Without removing this element, we get a "`log_protected_attribute_removal': undefined method `debug' for nil:NilClass (NoMethodError)"
  # why ????
  val["attributes"].delete("id")

  warn "Creating object class: #{klass} values: #{val["attributes"].inspect}"

  if klass == NetworkElement then
    NetworkElement.new(val["attributes"])
  end

  if klass == GraphLabel then
    GraphLabel.new(val["attributes"])
  end
    #YAML.object_maker(klass,val)
end

class ActiveRecord::Base
  def to_yaml_type
    "!yaml.org,2002:#{self.class}"
  end
end

# database.yml [3] =
#- adapter: mysql
#  host: localhost
#  database: VNet_db

$config = YAML.load_file(File.join(File.dirname(__FILE__), 'database.yml'))
ActiveRecord::Base.establish_connection $config[3]

# Just make sure database is empty...
  NetworkElement.delete_all
  GraphLabel.delete_all

# Create the master object and 2 slave objects
  gl1 = GraphLabel.create(:role_identifier => "SNode 111", :graph_type => "ML", :graph_nr => 0)
  gl1.network_elements.create(:identifier => "testnode1", :alias => "testnode1alias", :ne_type => "/node/host/generic")
  gl1.network_elements.create(:identifier => "testnode2", :ne_type => "/node/host/generic")

# use of warn(stderr) instead of print(stdin) for unbuffered-readable output in Windows

# Create yaml file with contents of the database ...
  graph = GraphLabel.first(:include => :network_elements)
  gf = File.open("graph.yml","w")
  gf.write graph.to_yaml
  gf.close

# Empty database AGAIN.
  NetworkElement.delete_all
  GraphLabel.delete_all

# Try to recreate from the yaml file the objects and it's associations...
File.open( 'graph.yml' ) do |yf|
  YAML.each_document( yf ) do |gl|
    # if we comment  the YAML.add_domain_type and AR::Base blocks, we get a full dump, but still no network_elements array filled...
    warn gl.to_yaml

    if gl.network_elements.count > 0 then
      gl.network_elements.first.alias = "alias field changed"
      warn gl.network_elements.first.to_yaml
#      gl.instance_variable_set("@new_record", true)
#      gl.id = nil
#      gl.save!    # Updates or creates a new one?
      warn gl.network_elements.first.to_yaml
    else
      warn "   ==> Error: Net Elem array is empty!!!"
    end
#    warn gl.to_yaml
  end
end

warn "\nScript has finished."

#Database creation

#CREATE  TABLE IF NOT EXISTS `VNet_db`.`graph_labels` (
#  `id` INT NOT NULL AUTO_INCREMENT ,
#  `role_identifier` VARCHAR(45) NOT NULL COMMENT 'VNP A' ,
#  `graph_type` VARCHAR(2) NOT NULL COMMENT 'OL ML UL' ,
#  `graph_nr` INT NOT NULL COMMENT 'OL/UL#n(from top/bottom)' ,
#  `graph_tag` VARCHAR(45) NULL ,
#  `v_net_identifier` VARCHAR(120) NULL ,
#  PRIMARY KEY (`id`) )
#ENGINE = InnoDB;
#
#CREATE  TABLE IF NOT EXISTS `VNet_db`.`network_elements` (
#  `id` INT NOT NULL AUTO_INCREMENT COMMENT 'elementID (db purposes)' ,
#  `identifier` VARCHAR(120) NOT NULL DEFAULT 'unused' COMMENT 'ID as in topology description' ,
#  `alias` VARCHAR(120) NULL DEFAULT NULL COMMENT 'alias name (as given by the role managing this db)' ,
#  `ne_type` VARCHAR(20) NOT NULL DEFAULT '/node/host/generic' COMMENT 'host/switch/router' ,
#  `console_interface_id` INT NULL DEFAULT NULL ,
#  `customer_console_interface_id` INT NULL ,
#  `graph_label_id` INT NULL ,
#  `provisioning_interface_id` INT NULL ,
#  PRIMARY KEY (`id`) ,
#  INDEX `fk_network_elements_graph_labels1` (`graph_label_id` ASC) ,
#  CONSTRAINT `fk_network_elements_graph_labels1`
#    FOREIGN KEY (`graph_label_id` )
#    REFERENCES `VNet_db`.`graph_labels` (`id` )
#    ON DELETE CASCADE
#    ON UPDATE NO ACTION,
#ENGINE = InnoDB;

# Database contents in YAML format
#
#--- !yaml.org,2002:GraphLabel
#attributes:
#  graph_type: ML
#  id: "340"
#  role_identifier: SNode 111
#  v_net_identifier:
#  graph_tag:
#  graph_nr: "0"
#attributes_cache: {}
#
#network_elements:
#- !yaml.org,2002:NetworkElement
#  attributes:
#    graph_label_id: "340"
#    ne_type: /node/host/generic
#    id: "866"
#    provisioning_interface_id:
#    console_interface_id:
#    alias: testnode1alias
#    identifier: testnode1
#    customer_console_interface_id:
#  attributes_cache: {}
#
#- !yaml.org,2002:NetworkElement
#  attributes:
#    graph_label_id: "340"
#    ne_type: /node/host/generic
#    id: "867"
#    provisioning_interface_id:
#    console_interface_id:
#    alias:
#    identifier: testnode2
#    customer_console_interface_id:
#  attributes_cache: {}
#