require 'mongoid'
require 'pp'

Mongoid.load!('mongoid.yml', :test)

# the big container object
class Book
  include Mongoid::Document
  embeds_many :pages
end

# the smaller embeded_in object
class Page
  include Mongoid::Document
  embedded_in :book
  embeds_many :notes
  field :content, :type => String
end

# and one more time
class Note
  include Mongoid::Document
  embedded_in :page
  field :message, :type => String
end

# clear previous test cases
Book.mongo_session[Book.collection.name].drop

# setup the basic object

book = Book.new({
  :pages => [
    {
      content: "Page 1", 
      notes: [ 
        { message: "Page 1 / Note A" },
        { message: "Page 1 / Note B" }
      ]
    },
    {
      content: "Page 2", 
      notes: [ 
        { message: "Page 2 / Note A" },
        { message: "Page 2 / Note B" }
      ]
    }
  ]
})
book.id = '123'
book.save

puts "---------------- A good copy of the document"
pp book.as_document

require 'mongoid'
require 'pp'
require 'byebug'
require 'pry-byebug'

Mongoid.load!('mongoid.yml', :test)

# the big container object
class Book
  include Mongoid::Document
  embeds_many :pages
end

# the smaller embeded_in object
class Page
  include Mongoid::Document
  embedded_in :book
  embeds_many :notes
  field :text, :type => String

  if true # true, breaks the code; false, allows the code to work.
    after_initialize do
      if self[:content]
        self[:text] = self[:content]
        self.remove_attribute(:content)
      end
    end
  end
end

class Note
  include Mongoid::Document
  embedded_in :page
  field :message, :type => String
end

book = Book.find '123'
# we will now remove those notes, and a new "C" note
book.pages.each do | page | 
  # going to make sure we actually clear it
  page.notes.clear
  page.notes = nil
  page.notes.destroy_all
  page.save
  page.notes.new(message: "Note C")
  page.save
end

if ! book.save
   puts "-------------- Oh noes! We didn't save"
end

puts "---------------- We have removed all notes from all pages; and added a new 'Note C'; Below is correct"
pp book.as_document

puts "\n\n---------------- Now reloading the book we see that 'Note C' was never saved"
book = Book.find '123'
pp book.as_document

$ bundle exec ruby test.rb
---------------- A good copy of the document
{"_id"=>"123",
 "pages"=>
  [{"_id"=>"525e0b789f4a1a800c000001",
    "content"=>"Page 1",
    "notes"=>
     [{"_id"=>"525e0b789f4a1a800c000002", "message"=>"Page 1 / Note A"},
      {"_id"=>"525e0b789f4a1a800c000003", "message"=>"Page 1 / Note B"}]},
   {"_id"=>"525e0b789f4a1a800c000004",
    "content"=>"Page 2",
    "notes"=>
     [{"_id"=>"525e0b789f4a1a800c000005", "message"=>"Page 2 / Note A"},
      {"_id"=>"525e0b789f4a1a800c000006", "message"=>"Page 2 / Note B"}]}]}
$ bundle exec ruby test2.rb
---------------- We have removed all notes from all pages; and added a new 'Note C'; Below is correct
{"_id"=>"123",
 "pages"=>
  [{"_id"=>"525e0b789f4a1a800c000001",
    "notes"=>[{"_id"=>"525e0b7b9f4a1aec2c000001", "message"=>"Note C"}],
    "text"=>"Page 1"},
   {"_id"=>"525e0b789f4a1a800c000004",
    "notes"=>[{"_id"=>"525e0b7b9f4a1aec2c000002", "message"=>"Note C"}],
    "text"=>"Page 2"}]}


---------------- Now reloading the book we see that 'Note C' was never saved
{"_id"=>"123",
 "pages"=>
  [{"_id"=>"525e0b789f4a1a800c000001",
    "notes"=>
     [{"_id"=>"525e0b789f4a1a800c000002", "message"=>"Page 1 / Note A"},
      {"_id"=>"525e0b789f4a1a800c000003", "message"=>"Page 1 / Note B"}],
    "text"=>"Page 1"},
   {"_id"=>"525e0b789f4a1a800c000004",
    "notes"=>
     [{"_id"=>"525e0b789f4a1a800c000005", "message"=>"Page 2 / Note A"},
      {"_id"=>"525e0b789f4a1a800c000006", "message"=>"Page 2 / Note B"}],
    "text"=>"Page 2"}]}
$